Zootaxa, Revision of the crab genus Garthambrus Ng, 1996, with the ...

Zootaxa 2122: 1–50 (2009) www.mapress.com / zootaxa/ Copyright © 2009 · Magnolia Press

ISSN 1175-5326 (print edition)

Article

ZOOTAXA ISSN 1175-5334 (online edition)

Revision of the crab genus Garthambrus Ng, 1996, with the description of two new genera and discussion of the status of Tutankhamen Rathbun, 1925 (Crustacea: Brachyura: Parthenopidae) COLIN L. MCLAY1 & S. H. TAN2 ,3 1

School of Biological Sciences, University of Canterbury, Christchurch, New Zealand. E-mail: [email protected] Raffles Museum of Biodiversity Research, Department of Biological Science, National University of Singapore, 6 Science Drive 2, Level 3, Singapore 117546, Republic of Singapore 3 Corresponding author: E-mail: [email protected] 2

Table of contents Abstract ............................................................................................................................................................................... 2 Introduction ......................................................................................................................................................................... 2 Materials and methods ........................................................................................................................................................ 3 Systematic account .............................................................................................................................................................. 7 Parthenopinae Macleay, 1838 ............................................................................................................................................. 7 Garthambrus Ng, 1996 ....................................................................................................................................................... 7 Key to Garthambrus species ............................................................................................................................................... 9 Garthambrus poupini (Garth, 1993) ............................................................................................................................ 9 Garthambrus allisoni (Garth, 1993) .......................................................................................................................... 11 Garthambrus cidaris (Garth & Davie, 1995) ............................................................................................................ 12 Garthambrus complanatus (Rathbun, 1906) ............................................................................................................. 13 Garthambrus darthvaderi sp. nov. ............................................................................................................................ 13 Garthambrus lacunosus (Rathbun, 1906) .................................................................................................................. 16 Garthambrus posidon Ng, 1996 ................................................................................................................................ 17 Garthambrus pteromerus (Ortmann, 1893) nov. comb............................................................................................. 17 Garthambrus stellatus (Rathbun, 1906) .................................................................................................................... 20 Garthambrus tani Ahyong, 2008................................................................................................................................ 22 Garthambrus undulatus sp. nov. ............................................................................................................................... 30 Hispidolambrus gen. nov. ................................................................................................................................................ 32 Hispidolambrus mironovi (Zarenkov, 1990) nov. comb. ......................................................................................... 33 Zarenkolambrus gen. nov. ................................................................................................................................................. 35 Key to Zarenkolambrus species ....................................................................................................................................... 35 Zarenkolambrus minutus sp. nov. .............................................................................................................................. 35 Zarenkolambrus epibranchialis (Zarenkov, 1990) comb. nov. ................................................................................. 38 Tutankhamen Rathbun, 1925 ............................................................................................................................................. 39 Tutankhamen cristatipes (A. Milne-Edwards, 1880) ................................................................................................. 40 Key to genera .................................................................................................................................................................... 43 Discussion ......................................................................................................................................................................... 43 Acknowledgements ........................................................................................................................................................... 44 References ......................................................................................................................................................................... 44

Accepted by P. Castro: 18 Apr. 2009; published: 1 Jun 2009

1

Abstract The Indo-West Pacific genus Garthambrus Ng, 1996, is revised. Two new species are described from New Caledonia and French Polynesia. Lambrus (Parthenopoides) pteromerus Ortmann, 1893, is now transferred to Garthambrus. The genus now consists of 11 nominal species, viz. G. allisoni (Garth, 1992), G. cidaris (Garth and Davie, 1995), G. complanatus (Rathbun, 1906), G. lacunosus (Rathbun, 1906), G. posidon Ng, 1996, G. poupini (Garth, 1992), G. pteromerus (Ortmann, 1892), G. stellatus (Rathbun, 1906), G. tani Ahyong, 2008, G. darthvaderi sp. nov. and G. undulatus sp. nov. Although originally included in Garthambrus, Asterolambrus mironovi Zarenkov, 1990, is herein transferred to a new genus, Hispidolambrus gen nov. Most of these species are known from the West Pacific, but Garthambrus posidon only occurs in the Indian Ocean. Most specimens of Garthambrus have been collected from depths between 81–600 m. The monotypic Caribbean genus Tutankhamen Rathbun, 1925, which closely resembles Garthambrus, is also discussed. Heterocrypta epibranchialis Zarenkov, 1990, has some resemblance to Garthambrus but is here referred to a new genus, Zarenkolambrus, along with a new species, Z. minutus sp. nov. Key words: Garthambrus, Hispidolambrus, Tutankhamen, Zarenkolambrus, Parthenopidae, taxonomy, Pacific Ocean, Caribbean Sea, Indian Ocean, new species, new genus

Introduction The large number of parthenopids collected during MUSORSTOM expeditions, and held in the Muséum national d’Histoire naturelle, Paris, offered the opportunity to revise many of the genera in this family. The bulk of this work, which includes many undescribed new species, remains part of an unpublished doctoral dissertation (Tan, 2004). Tan & Ng (2007) updated the generic system of the Parthenopidae Macleay, 1838 and they synonymised the subfamilies, Cryptopodiinae Stimpson, 1871, and Lambrachaeinae Števčić, 1994, with the Parthenopinae Macleay, 1838. They recognised 32 genera, of which 12 were described as new, and provided a key to these genera. The present paper deals with the genus Garthambrus Ng, 1996, a discussion about the related genus Tutankhamen Rathbun, 1925, and the description of new genera, Hispidolambrus gen. nov. and Zarenkolambrus gen. nov., that are closely allied to Garthambrus. The genus Garthambrus was established by Ng (1996) for a number of species previously placed in Platylambrus Stimpson, 1871, a heterogeneous group that was in urgent need of revision. Tan & Ng (2007) later recognised several genera that were previously placed in Platylambrus sensu lato viz. Spinolambrus Tan & Ng, 2007, and Piloslambrus Tan & Ng, 2007. The genus Platylambrus is now restricted to only two species in the Atlantic, P. serratus (H. Milne Edwards, 1834) and P. granulatus (Kingsley, 1879) (Tan & Ng, 2007: 99). Ng (1966) differentiated Garthambrus from Platylambrus mainly by the shape of the carapace. Six species were included in the genus at that time: G. complanatus (Rathbun, 1906), G. lacunosus (Rathbun, 1906), G. mironovi (Zarenkov, 1990), G. posidon Ng, 1996, G. poupini (Garth, 1993) and G. stellatus (Rathbun, 1906). Herein we place G. mironovi in a new genus. The carapace of Garthambrus has strongly inflated gastric, cardiac and branchial regions, lacks sub-cylindrical or sub-lamelliform spines on the metabranchial region and posterior epibranchial margins, a trifid rostrum, broad posterior epistomial margin, and a G2 which has an elongate flagellum as long as or longer than the length of the thickened basal part. The definition of Garthambrus needs to be modified in order to accommodate the species originally included, especially with reference to the smooth carapace surface of some species. The inclusion of species that do not have a tuberculate carapace means that the carapace surface character must be expanded to become “dorsal surface tuberculate, smooth or pitted. In a paper on the parthenopids of Hawaii, Ng & Tan (1999) elaborated on the three species of Garthambrus found there (G. complanatus, G. lacunosus and G. stellatus), added two more species, G. allisoni (Garth, 1993) and G. cidaris (Garth & Davie, 1995), and provided a key to all species included in Garthambrus at the time. Ahyong (2008) recently described a new species, G. tani Ahyong, 2008, from New Zealand, which is also the first record of a parthenopid species from that area.

2

· Zootaxa 2122 © 2009 Magnolia Press

MCLAY & TAN

Results from the present study indicate that the genus Garthambrus now consists of 11 species. Other than the aforementioned species, Lambrus (Parthenopoides) pteromerus Ortmann, 1893, was also found to belong to Garthambrus, and two new species are described herein: G. darthvaderi sp. nov. and G. undulatus sp. nov. The monotypic Caribbean genus Tutankhamen, which closely resembles Garthambrus, is also discussed. Heterocrypta epibranchialis Zarenkov, 1990, which bares some resemblance to Garthambrus, is here referred to a new genus, Zarenkolambrus, along with a new species Z. minutus sp. nov. Both species have triangular “arrow-head shaped bodies. The very spinous Asterolambrus mironovi Zarenkov, 1990 is transferred from Garthambrus to Hispidolambrus gen. nov.

Materials and methods Measurements of the carapace dimensions are given as CW x CL, in millimetres, measured at the tips of the lateral teeth, and along mid-line respectively. The complexity of the parthenopid carapace and conflicting use of terms by various authors demands that our descriptive terms be clearly defined. A tubercle is defined as a protuberance that is more or less smooth and slightly taller than wide. When a tubercle is covered with numerous, much smaller protuberances, it is described as granular. Some tubercles may support a plate-like structure at the tip. This type of tubercle is described as paxillate. The edges of the plate-like structure are usually irregular, but in some cases there are small spines extending from the edges. This type of paxilliform tubercle is described as stellate (Fig. 1).

FIGURE 1. Stellate paxilliform tubercles of Garthambrus stellatus (Rathbun, 1906).

Terminology used is depicted in Figs. 2–4 and is largely self explanatory. Terms used deviate considerably from Flipse (1930) because they were not treated in sufficient detail, as in the carapace margins and the position and terminology of the carapace grooves. Flipse (1930) used the archaic term “sulcus semilunaris” but this has been designated here as the “branchiocardiac groove”. The shape of the hepatic margin of the carapace is a useful feature to distinguish the genera dealt with herein. In some genera it forms a right angle that we term the “hepatic shoulder” whose corner may be variously ornamented. The anterior epibranchial margin varies in shape and it terminates at a corner that may carry the lateral tooth. The boundary between the hepatic and epibranchial margins may be marked by a hepatobranchial notch. The abbreviation P refers to the pereopods, with P1 being the chelipeds and P2, P3, P4 and P5 are the first, second, third and fourth pairs of ambulatory legs respectively. The propodus of the cheliped is referred to as the manus and is prismatic in cross-section. The manus has three margins, which are usually dentate. The row of teeth facing outwards away from the frontal region is on the outer margin, the row facing upwards is on the upper margin, and the row that is beneath the upper margin and faces downwards is on the lower margin. The surface between the outer and the upper margins is called the upper surface, that between the upper and the lower margins is called the inner surface and that between the lower margin and the outer margin is called the lower surface. Use of the term “dorsal surface” in relation to the pereopods is not appropriate with these crabs.

REVISION OF THE CRAB GENUS GARTHAMBRUS

Zootaxa 2122 © 2009 Magnolia Press ·

3

FIGURE 2. Selected figures illustrating the terminology used to describe regions, margins and teeth on the dorsal surface

of the carapace of a generalised Garthambrus species: A, regions and teeth; B, carapace grooves and margins.

The number of tubercles on the margins of the P2–P5 meri, carpi, propodi and dactyli are described as the number on the superior margin over the number on the inferior margin. The anterior-most row is given first in cases where there are two rows of tubercles: “Merus 9/(9 + 11)” means that there are 9 tubercles on the superior margin and two rows on the inferior margin, with 9 tubercles in the anterior-most row and 11 in the more posterior row. “0/0” indicates that there are no tubercles on either margin. The same convention is used for the carpus.

4


MCLAY & TAN

FIGURE 3. Terminology used in this work based on a generalised Garthambrus species: A, ventral regions (note absence

of the sub-gastrobranchial groove); B, view of the anterior ventral portion of the carapace.



5

FIGURE 4. Selected figures illustrating the terminology used to describe crabs of the genus Garthambrus based on G.

pteromerus (Ortmann, 1893): A, right major chela; B, right major chela, outer surface; C, male abdomen; D, female abdomen.

In all Garthambrus species, and also in almost all parthenopids, the merus of the chelipeds interact with the teeth on the epibranchial margin in such a way that the chelipeds are prevented from being extended all the

6


MCLAY & TAN

way backwards. In addition, there is either a tooth or several teeth on the sub-epibranchial region that also interact with the teeth on the proximal part on the outer margin of the cheliped merus that restrict posterior movement of the chelipeds. We refer to this as the “cheliped-blocking mechanism”. It is not clear why this interaction of the teeth on the carapace and those on the cheliped merus exists. The male abdomen has segments three to five fused with the sutures absent. In the female, all abdominal segments are free with well defined sutures. In addition, the press button, located on sternite five and used as the abdominal locking mechanism (see Guinot & Bouchard 1998), is present in mature female specimens as well as males. The first and second male gonopods are abbreviated as G1 and G2 respectively. The narrow distal portion of G2 is referred to as the flagellum while the thicker proximal portion is referred to as the basal section. Note that not all of the gonopods are drawn from the same view or angle. Differences are noted in the figure captions. For Hispidolambrus mironovi nov. comb. (Fig. 16C, D) and Zarenkolambrus epibranchialis nov. comb. (Fig. 18C, D) the gonopods have not been drawn by the present authors, but are reproduced from the original publication, so that they are not of equal quality and detail. The female gonopore is usually closed by a flexible cover, but it should not be described as “operculate” because the cover is not calcified and there is no hinge line. When comparing some older parthenopid descriptions with those given here, particular attention needs to be paid to the terms used for the antennae. We have standardized the terms used so as to ensure proper numbering of the articles of these two appendages. The articles of the antenna are numbered from 1 to 4. Article 1 has been called by other authors the “urinary article” while article 2 has been called the “basal article”. The first article in these crabs is mobile, not embedded in the epistome, while the second article is fixed to the epistome on one side and the sub-orbital margin on the other and so is immobile. Almost all the material examined for this study was collected during numerous MUSORSTOM expeditions and deposited in the Muséum national d’Histoire Naturelle, Paris (MNHN,). Other specimens are deposited in the following institutions: Bernice P. Bishop Museum, Honolulu (BPBM); Queensland Museum, Brisbane (QM); Los Angeles County Museum (LACM); Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts (MCZ); Natural History Museum, London (NHM); National Institute of Water and Atmospheric Research Ltd., Wellington, New Zealand (NIWA); Department of Aquaculture of the National Kaohsiung Institute of Marine Technology, Taiwan (NKIMT); National Science Museum, Tokyo (NSMT); National Taiwan Ocean University, Taiwan (NTOU); Rijksmuseum van Natuurlijke Histoire, Leiden (RMNH); Natur-Museum und Forschung Institut Senckenberg, Frankfurt (SMF); National Museum of Natural History, Smithsonian Institution, Washington D. C. (USNM); Instituut voor Taxonomische Zoologie (Zoologisch Museum), Amsterdam (ZMA); Zoologisk Museum, Copenhagen (ZMUC); Zoological Reference Collection, Raffles Museum of Biodiversity Research, National University of Singapore, Singapore (ZRC).

Systematic Account Parthenopinae Macleay, 1838 Garthambrus Ng, 1996 Garthambrus Ng, 1996: 156. – Ng & Tan 1999: 121. – Davie 2002: 387. – Tan & Ng, 2007: 99. – Ng et al., 2008: 130.

Type species. Parthenope (Platylambrus) poupini Garth, 1993, by original designation. Gender masculine. Other species included. G. allisoni (Garth, 1993), G. cidaris (Garth & Davie, 1995), G. complanatus (Rathbun, 1906), Garthambrus darthvaderi sp. nov., G. lacunosus (Rathbun, 1906), G. posidon Ng, 1996, G. pteromerus (Ortmann, 1893), G. stellatus (Rathbun, 1906), G. tani Ahyong, 2008, and G. undulatus sp. nov. Diagnosis. Carapace sub-triangular to pentagonal, broader than long, regions inflated; dorsal surface granulose, tuberculate, smooth or pitted; anterior epibranchial margin expanded, partially covering ambulatory legs; not produced beyond base of abdomen; no lateral ventral depression. Postorbital angle



7

broadly acute. Hepatic margin distinct, not continuous with anterior epibranchial margin. Hepatobranchial notch present, distinct. Anterior epibranchial margin convex to slightly convex; teeth triangular to subtriangular, triangular gaps between adjacent teeth present. Proto-, meso-, metagastric regions distinct, without ridges. Hepatic region slightly inflated, lower than anterior epibranchial gastric regions. Sub-orbital region without diagonal ridge, usually depressed or excavated; upper suborbital margin gently curving. Epistome slightly depressed medially, smooth, tuberculate or pitted, without protrusion below antennular article 1, lower margin broadly chevron-shaped. Pterygostomial region not excavated, afferent channel not distinct. Pterygostomial ridge present, without dense setae covering afferent channel, not continuous with sub-epibranchial ridge, sub-hepatobranchial notch present. Sub-epibranchial region smooth or tuberculate. Posterior sub-branchial teeth absent. Antennal article 3 long, reaching to disto-lateral corner of antennular article 1; antennal article 4 above disto-lateral corner of antennular article 1, half antennal length of article 3. Merus of third maxilliped subquadrate, upper margin usually entire; distal portion of carpus upper surface with small tubercle; propodus and dactylus hidden; exopod exposed, mesial margin distal one-third with tooth. Cheliped margins dentate, teeth relatively short, triangular; upper surface of merus smooth to tuberculate, with median row of tubercles; dactylus down-curved Male thoracic sternum fused, tuberculate to smooth, depressed; transverse and longitudinal grooves present, fused medially, forming inverted V-shaped depression. Male telson triangular, equilateral. G1 relatively stout, tip rounded, not armed with long spines or stiff setae. G2 longer than G1; flagellum longer or subequal to basal section. Remarks. The genus Garthambrus was established by Ng (1996) to separate several species of Indo-West Pacific parthenopids that were placed in the genus Platylambrus Stimpson, 1871. Despite the separation, Platylambrus still appears to be heterogeneous. Ng (1996) broadly divided Platylambrus sensu lato into two groups. The first group consists of Lambrus serratus H. Milne Edwards, 1834, and Lambrus granulatus Kingsley, 1879, the only two species that should be placed in Platylambrus sensu stricto [type species: Lambrus crenulatus Saussure, 1858 (= Lambrus serratus H. Milne Edwards, 1834)] (see Gore 1977). The other group consists of all the Indo-West Pacific and American species currently placed in Platylambrus. Although not specified by Ng (1996), the American species clearly refers to representatives from both the Atlantic and eastern Pacific Oceans. The Atlantic group is homogenous whereas the eastern Pacific group is still very heterogeneous. Ng (1996) noted that this group is still “not sufficiently defined” and “any attempt to separate the Indo-West Pacific and Atlantic Platylambrus species at the generic level would be premature.” Tan & Ng (2007) restricted Platylambrus to only P. serratus and P. granulatus and for the other species formerly in Platylambrus, they placed all species from the Indo-West Pacific in Enoplolambrus A. MilneEdwards, 1878; two species from the Atlantic and eastern Pacific are referred to the genera, Spinolambrus Tan & Ng, 2007, and Piloslambrus Tan & Ng, 2007, respectively. According to Ng (1996) Garthambrus is “almost certainly a deep water genus” since most species have been obtained from considerable depths. This is clearly not true for all species in the genus as Garthambrus pteromerus has been collected from depths of around 81 m. The definition of this genus is also revised to accommodate several new species described herein and species that were previously overlooked. Of the eight species included in Garthambrus by Ng (1996) only seven remain: G. mironovi (Zarenkov, 1990) from the Eastern Pacific is herein transferred to a new genus. Including the new species, eleven Garthambrus species are now recognised. All of these species are found in the Indo-West Pacific.

8


MCLAY & TAN

Key to Garthambrus species 1.

Posterior edge of metabranchial region with a raised triangular patch and anterior epibranchial margin with wellseparated evenly-spaced teeth each bearing minute spinules .............................................................. G. complanatus Posterior edge of metabranchial region without raised triangular patch and anterior epibranchial margin otherwise 2 2. Posterior edge of metabranchial region with several tubercles, which can be stellate or granular leading to edge of posterior margin .......................................................................................................................................................... 3 Posterior edge of metabranchial region with either a spine or tubercle, not leading to edge of posterior margin ..... 4 3. Dorsal surface of carapace with paxillate tubercles; tubercles on upper margin of ambulatory legs rounded at tip; tubercles on surfaces of ambulatory legs well spaced .................................................................................. G. poupini Dorsal surface of carapace with stellate granules; sharp tipped tubercles on upper margin of ambulatory legs; tubercles on surfaces of ambulatory legs very close together ............................................................................... G. allisoni 4. Upper margin of ambulatory legs cristate ................................................................................................................... 5 Upper margin of ambulatory legs tuberculate ............................................................................................................ 7 5. Subhepatic region not excavated ............................................................................................................... G. lacunosus Subhepatic region excavated ...................................................................................................................................... 6 6. Hepatic tooth absent. Hepatic cavity broad and deep ............................................................................ G. darthvaderi Hepatic tooth present. Hepatic cavity narrow and shallow .................................................................... G. pteromerus 7. Upper margin of ambulatory legs with only one or two rounded tubercles on proximal and distal portion, middle portion smooth .............................................................................................................................................. G. posidon Upper margin of ambulatory legs with well-spaced tubercles on entire upper margin .............................................. 8 8. Dorsal surface of carapace densely covered with granulate tubercles, ambulatory legs with spines ......... G. stellatus Dorsal surface of carapace not densely tuberculate, ambulatory legs without spines ................................................ 9 9. Distal tubercles of upper margin of ambulatory leg meri flattened laterally, sub-cristatiform. Hepatic tooth cristatiform. Teeth on anterior epibranchial margin narrow, well-spaced from each other .......................................... G. tani Distal tubercles of upper margin of ambulatory leg meri not flattened laterally. Hepatic shoulder forms right-angle not cristatiform. Teeth on anterior epibranchial margin broad, bases almost adjacent ............................................. 10 10. Lateral tooth at epibranchial corner short, not elongated. Tubercles on dorsal surface of carapace paxilliform .......... ........................................................................................................................................................................ G. cidaris Lateral tooth at epibranchial corner elongated, tip acute. Tubercles on dorsal surface of carapace not paxilliform ..... ................................................................................................................................................................... G. undulatus

Garthambrus poupini (Garth, 1993) (Figs 5A, B, 9A) Parthenope (Platylambrus) poupini Garth, 1993: 782, figs 1, 2. Garthambrus poupini — Ng 1996: 159. – Ng & Tan 1999: 122.

Type material. HOLOTYPE: male 35.5 x 28.0 mm (MNHN-B22424), French Polynesia, Tuamotu, Fangataufa, SMCB stn 84, 22°11.1’S, 138°45.1’W, 520–570 m, 22 Jul 1988. PARATYPES: 1 male 37.9 x 28.9 mm (MNHN-B 21364), French Polynesia, Tuamotu, Fangataufa, SMCB stn 135, 22º15.2’S, 138º46.3’W, 720 m, 25 Feb 1989; 1 male 39.4 x 29.9 mm (MNHN, MP B-22420), French Polynesia, Tuamotu, Fangataufa, SMCB stn 395, 22°15.3’S, 138°42.9’W, 660 m, 15 Mar 1991; 1 female 25.6 x 19.4 mm (MNHN, MP B-21363), Moruroa, SMCB: stn 125, 21°51’S, 138°47’W, 530–630 m, 29 Oct 1988. Material examined. New Caledonia: CHALCAL II: stn DW74, 24°40.36’S, 168°38.38’E, 650 m, 29 Oct 1986: 1 male 10.0 x 8.0 mm (MNHN). SMIB 8: stn DW151, 24°53.0’S, 168°21.4’E, 530–547 m, 27 Jan 1993: 1 female 14.1 x 11.0 mm (MNHN). Redescription. Carapace shape pentagonal, wider than long, ratio CW/CL = 1.3, surface covered with mixture of coarse, fine granules. Larger granules fungiform-shaped, all granules bear tiny granules themselves. Rostrum elongate, prominent, horizontal, increasing in thickness near tip. Frontal region concave, dorsal orbital area swollen into 2 convex parts separated by notch. Protogastric region with 2 more densely granular, convex areas. Broad median ridge of denser granules extends across mesogastric, metagastric areas,



9

on to cardiac region. Anterior branchial region bears 2 prominent ridges: anterior diagonal ridge lies at lower level than posterior diagonal ridge, which is more densely granular, ends just behind posterior epibranchial corner. Posterior branchial region with short, densely granular ridge. Branchiocardiac groove contains 3 well marked pits with large paxillate tubercle. Orbital margin granular, strongly concave posteriorly, supraorbital suture partially obscured by granules. Margin of suborbital region concave, ending bluntly. Posterior corner of hepatic margin with granular swelling followed by small tooth before hepatic notch. Anterior epibranchial margin with 11 truncated teeth decreasing in size posteriorly until reaching large posterior slightly upturned epibranchial tooth. Posterior epibranchial margin slightly concave without teeth. Posterior margin with 3 heavily granular swellings separated by short concave areas. Epistome T-shaped with central broadly V-shaped depression, shallow concavity at each end. Subhepatic region concave without fissure. Well marked, closely spaced line of granules begins at corner of buccal frame, extending posteriorly across pterygostomial region. After interruption by hepatic notch, line of granules continues on to sub-branchial region. Cheliped-blocking mechanism consists of stout proximal spine on posterior margin of cheliped merus meeting large sub-branchial spine. Deep U-shaped depression on sternites 3, 4 with large tubercle at each corner. Sternites 5–7 have small slightly projecting tuberculate ridges each proceeded by small depression. Sternal sutures 4/5, 5/6, 6/7, 7/8 all interrupted. Eyes mobile, eyestalks granular, short, diameter same as cornea, margin of orbit incomplete ventrally, orbital fossa deep, formed by lateral, suborbital margin, around 80% of cornea is concealed when eye is folded away.

FIGURE 5. Gonopods. Garthambrus poupini (Garth, 1993): A, B, holotype, male 35.5 x 28.0 mm (MNHN B 22424), French Polynesia, Tuamotu Archipelago, Fangataufa (after Garth 1992: figs. 2d, e) (scale bar not available). — Garthambrus allisoni (Garth, 1993): C, D, holotype, male 23.5 x 17.8 mm (LACM; ex. AHF 645), Easter I. Fracture Zone (after Garth 1992: fig. 5f ) (scale bar = 1 mm). — Garthambrus complanatus (Rathbun, 1906): E, F, lectotype, male 17.3 x 12.7 mm (USNM 29845a), Hawaiian Is, Kauai (scale bar = 1mm). A, E, left G1; B, F, left G2; C, right G1; D, right G2.

10


MCLAY & TAN

Article 1 of antennule mobile, 6-sided; article 2 much longer than wide, inserted medially, folded away at an oblique angle; articles 3, 4 normally kept folded away in antennular fossa. Article 1 of antenna mobile, wider than long, convex; article 2 trapezoidal, convex, fixed to epistome, suborbital margin; articles 3, 4 mobile, longer than wide; flagellum as long as articles 3, 4 combined. Basis-ischium of third maxilliped with central longitudinal cavity, medial side with edentate knife-like margin. Merus wider than long with 2 concavities separated by ridge. Lateral corner covers distal end of exopod. Carpus forms part of external cover, but propodus, dactylus hidden beneath merus of endopod. Inner margin of cheliped merus with 11 or 12 well developed granules interspersed with smaller ones; outer margin with similar number, especially large granule mid-way. Surface of carpus granular. Margins of propodus have about 12 granules of varying size, last 3 granules on inner margin curve up towards base of dactylus. Upper margin of dactylus with 3 blunt granules. Right cheliped a crusher with 3 or 4 obsolete distal teeth while left cheliped a cutter with similar number of weakly developed interlocking teeth. Male cheliped length 2.2 x CW or 2.9 x CL. Length of walking legs decrease posteriorly. Arrangement of tubercles on legs: P2: merus 6/1, none on carpus or propodus; P3: merus 6/3, carpus 0/0, propodus, 1/0; P4: merus 5/(5 + 3), carpus 1/0, propodus 2/2; P5: merus 6/(7 + 5), carpus, 2/0, propodus 3/3. Dactyli unarmed, shorter than propodi. Abdominal segments 4–6 medially convex with median hooked tubercle on segment 6. Abdominal segments 3–5 fused in male, but sutures still mostly evident. Abdominal locking mechanism of smooth sternal tubercles on sternite 5 fitting into deep sockets on posterior corners of sixth abdominal segment. Telson triangular, wider than long, tip rounded. Telson medial pit present, surrounded by elevated granules. G1 extends to middle of sternite 5, while G2 extends to middle of sternite 4. Sperm aperture opens medially, tip covered with short, acute spines directed proximally. Spines only on distal 0.14 of G1 length. Ratio of lengths of G2/G1 = 1.22. Flagellum of G2, twisted, 0.48 of length, no notch marking transition from basal section to flagellum. Distribution. Previously recorded only from type locality, French Polynesia. Reported here for the first time from New Caledonia. Remarks. Garthambrus poupini can be distinguished from all other species of Garthambrus by the blunt tips of the epibranchial teeth and by the blunt tubercles on the outer margins of the cheliped merus, carpus and manus. In all the other Garthambrus species, the tips of the epibranchial teeth and the teeth on the outer margins of the cheliped are sharp or pointed. Ng (1996) recorded as a paratype a male specimen (MNHN MP B-22421) from SMCB stn 395. This is in error since this male specimen was not listed as a type specimen (Garth 1993).

Garthambrus allisoni (Garth, 1993) (Figs 5C, D, 9B) Parthenope (Platylambrus) allisoni Garth, 1993: 790, fig. 5 (in part). Garthambrus allisoni — Ng, 1996: 157.

Type material. HOLOTYPE: male 23.5 x 17.8 mm (LACM; ex. AHF 645), Easter I. Fracture Zone, 25º03’S 97º29’W, Carrousel Expedition, Dredge 5, stn 19, 591 m, Scripps Institution of Oceanography 64–527, 1 Aug 1964 (after Garth 1993). Originally deposited at the Alan Hancock Foundation collection, the holotype male was apparently transferred to the Natural History Museum of Los Angeles County along with Garth’s crab collection. It was given a LACM catalogue number but this specimen has been misplaced (G. Davis, pers. comm.). Material examined. Taiwan. MUSORSTOM EXPEDITION TAIWAN 1, stn DW56, 24º29.8’N 122º12.6’E to 24º28.1’N, 122º12.6’E, 438–539 m, 4 Aug 2000: 1 female14.1 x 10.9 mm (NTOU); Same data as above: 1 ovig. female 12.5 x 9.9 mm (ZRC 2001.2224).



11

French Polynesia. Bora Bora, SMCB, stn D32, 16º28.37’S, 151º47.52’E, 562 m, 23 Jun 1901: 1 female 14.1 x 11.0 mm (MNHN, MP B-22421). Diagnosis. Carapace dorsally tuberculate, not spinose, without deep lacunae; supra-orbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions fusing to form smooth ridges or plates. Frontal projection short, less than one quarter length of carapace. Epibranchial marginal teeth tips sharp. Mesobranchial margin with raised angular patch; patch not smooth. Sub-orbital spine produced, spine tip extending beyond anterior outer corner of antennal article 2. Sub-branchial region densely tuberculate. Cheliped merus and carpus outer margins tuberculate, tubercles irregular, granular, tips sharp. P5 merus, carpus and propodus upper margins tuberculate; posterior surface of merus, carpus and propodus tuberculate, tubercles paxilliform, stellate, edges fusing with adjacent tubercles. Distribution. Garthambrus allisoni is known from the type locality near the island of Bora Bora, French Polynesia, and is now recorded for the first time from Taiwan. Remarks. The specimen from Bora Bora (MNHN, MP B-22421) was originally listed by Garth (1993: 782) as Parthenope (Platylambrus) poupini. Re-examination of this specimen indicated that it should be referred to G. allisoni instead. The tips of the epibranchial teeth are serrated and not blunt, like those in G. poupini. In addition, the tubercles on the protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions fuse to form ridges, characters that are absent in G. poupini. This species is one of two Garthambrus species that have stellate tubercles, the other being G. stellatus. It can be easily distinguished from G. stellatus, however, by having differently shaped epibranchial marginal teeth. In G. allisoni, the epibranchial teeth are arranged close together, whereas in G. stellatus, the epibranchial teeth are more widely spaced. In addition, G. allisoni has a fused patch of tubercles and ridges of tubercles on the dorsal surface of the carapace, which are absent in G. stellatus.

Garthambrus cidaris (Garth & Davie, 1995) (Fig. 10A) Parthenope (Platylambrus) cidaris Garth & Davie, 1995: 223, figs 1, 2A. Garthambrus cidaris — Ng 1996: 159. – Ng & Tan 1999: 122 (key). – Davie 2002: 387 (list).

Type material. HOLOTYPE: female 52.8 x 36.1 mm (QM W 16086), Australia, northeast Queensland, Coral Sea, CIDARIS II, stn 23–4, 14º52’S, 145º46’E, 685 m, epibenthic sledge 9 Sep 1988. Diagnosis. Carapace tuberculate, not spinose, without deep lacunae; supra-orbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial, mesobranchial, cardiac regions not fused to form smooth ridges or plates. Frontal projection short, less than one quarter carapace length. Tips of epibranchial margin teeth sharp. Mesobranchial margin without raised, smooth triangular patch. Sub-orbital spine produced, extending beyond anterior outer corner of antennal article 2. Sub-branchial region densely tuberculate. Cheliped merus, outer margins of carpus tuberculate, tubercle tips sharp. P5 merus, carpus, upper margins of propodus tuberculate; merus, carpus, posterior surface of propodus tuberculate; tubercles very small, low. Sternal sutures 4/5, 5/6, 6/7, 7/8 all interrupted. Male unknown. Distribution. Currently still only represented by the single female specimen from Queensland, Australia. Remarks. Garth & Davie (1995) compared G. cidaris with G. stellatus when they described the former species, and noted that it lacks the stellate tubercles of G. stellatus. They also noted that the epibranchial ridge is more swollen, that the branchiocardiac groove is deeper than in G. stellatus, and that the lateral tooth is spatulate. The lateral tooth is not spatulate in G. stellatus, but triangular. Garthambrus cidaris is closer to G. poupini than to G. stellatus. Garthambrus cidaris can be differentiated from G. poupini by having sharp-tipped teeth on the outer margins of the chelipeds The teeth on the epibranchial margin also have sharp tips in G. cidaris, but these are blunt in G. poupini.

12


MCLAY & TAN

Garthambrus complanatus (Rathbun, 1906) (Figs 5E, F, 10B) Parthenope (Platylambrus) stellata complanata Rathbun, 1906: 884. Parthenope (Platylambrus) stellata complanatus — Serène 1968: 60. Parthenope (Platylambrus) complanata — Garth 1993: 789. Parthenope complanata — Garth & Davie 1995: 226, fig. 3B. Garthambrus complanata — Ng 1996: 156, 158. – Ng & Tan 1999: 128, figs 4A–B, 6G–I

Type material. LECTOTYPE: male 17.3 x 12.7 mm (USNM 29845a), Hawaiian Is, Kauai, Hanamaulu Bay, RV Albatross, stn 4132, 22º01’30”N, 150º21’10”W, 470–570 m, 8 foot Blake beam trawl gear, 1 Aug 1902. PARALECTOTYPE: 1 male (USNM 29845b) (not examined), same data as lectotype. Diagnosis. Carapace tuberculate, not spinose, without deep lacunae; supra-orbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial, cardiac regions not fused to form smooth ridges or plates. Frontal projection short, less than one quarter carapace length. Epibranchial margin teeth broad, tips denticulate. Mesobranchial margin with raised, smooth, triangular patch. Sub-orbital spine produced, spine tip extending beyond anterior outer corner of antennal article 2. Posterior sub-branchial region sparsely tuberculate. Cheliped merus, carpus outer margins tuberculate, tubercle tips triangular. P5 merus, carpus, upper margins of propodus tuberculate; merus, carpus, posterior surface of propodus tuberculate; tubercles very small, low. Female unknown. Distribution. Known only from the Hawaiian Is. Remarks. One of the diagnostic features of this species is the presence of a smooth triangular patch at the metabranchial margin, which is absent in the other species of Garthambrus. A similar structure is seen in G. allisoni, but the patch is heavily tuberculate and vaguely shaped like an inverted ‘V’ rather than triangular.

Garthambrus darthvaderi sp. nov. (Figs 6A, B, 11) Type material. HOLOTYPE: male 19.9 x 14.0 mm (MNHN), New Caledonia, BIOCAL, stn DW44, 22°47’S, 167°14’E, 440–450 m, 30 Aug 1985. PARATYPES: 1 female 13.0 x 9.5 mm, 1 ovig. female 20.5 x 14.5 mm (MNHN), New Caledonia, MUSORSTOM IV, stn 162, 18º35.0’S, 163º10.3’E, 525 m, 16 Sep 1985; 1 female 17.8 x 13.4 mm (MNHN), BATHUS 3, stn DW838, 23º01’S, 166º56’E, 400–407 m, 30 Nov 1993; 1 female 19.2 x 13.4 mm (MNHN), BATHUS 4, stn DW925, 18º54.55’S, 163º23.75’E, 370–405 m, 7 Aug 1994. Material examined. New Caledonia. VAUBAN: Dredge 16 (ex DR2)”, 22º46’S, 167º12’E, 390–400 m, 10 Apr 1978: 1 female 14.1 x 9.9 mm (MNHN). MUSORTSOM IV: stn 230, 22º52.50’S, 167º11.80’E, 390–420 m, 30 Sep 1985: 1 female 20.4 x 14.1 mm (MNHN). BIOCAL: Stn DW77, 22º15’S, 167º15’E, 440 m, 5 Sep 1985: 1 female 18.0 x 13.0 mm (MNHN). MUSORSTOM IV: stn 162, 18º35.0’S, 163º10.3’E, 525 m, 16 Sep 1985: 1 ovig. female 20.5 x 14.5 mm (MNHN). SMIB 1: stn DW10, 22º54’S, 167º12’E, 410 m, 6 Feb 1986: 1 male 18.9 x 13.4 mm (MNHN). SMIB 2: stn DW14, 22º53’S, 167º13’E, 405–444 m, 18 Sep 1986: 1 male 19.4 x 13.6 mm, 1 female 18.1 x 12.7 mm (MNHN). MUSORSTOM V: stn 301, 22º06.9’S, 159º24.6’E, 487–610 m, 21 Oct 1986: 1 female 15.2 x 10.8 mm (MNHN); Stn 379, 19º53.20’S, 158º39.50’E, 370–400 m, 20 Oct 1986: 1 male 18.9 x 13.1 mm (MNHN). BERYX 11: stn DW11, 24º44’S, 168º10’E, 320–350 m, 16 Nov 1992: 1 male 19.0 x 13.1 mm (MNHN); Stn CP21, 24º44’S, 168º07’E, 430–450 m, 17 Oct 1992: 1 male 18.9 x 13.3 mm, 1 female 19.0 x 13.4 mm (MNHN). REVISION OF THE CRAB GENUS GARTHAMBRUS


13

SMIB 8: stn DW187, 23º17.7’S, 168º05.6’E, 390–540 m, 31 Jan 1993: 1 male 18.2 x 13.2 mm (MNHN); Stn DW189, 23º17.6’S, 168º05,5’E, 400–402 m, 31 Jan 1993: 1 male 15.4 x 10.8 mm, 1 female 18.9 x 13.3 mm (MNHN); Stn DW191, 22º57.5’S, 168º19.2’E, 564–580 m, 1 Feb 1993: 1 female 8.8 x 6.6 mm (MNHN). BATHUS 2: stn DW719, 22º47.57’S, 167º14.58’E, 444–455 m, 11 May 1993: 1 male 18.8 x 12.5 mm (MNHN); Stn DW729, 22º52.42’S, 167º11.90’E, 400 m, 12 May 1993: 1 female 19.4 x 12.0 mm (MNHN); Stn DW730, 23º02.56’S, 166º58.30’E, 397–400 m, 12 May 1993: 2 males 6.5 x 5.2, 8.0 x 5.9 mm, 2 females 9.0 x 6.5, 17.4 x 12.8 mm (MNHN); Stn CP736, 23º03.38’S, 166º58.96’E, 452–464 m, 13 May 1993: 1 female 15.8 x 10.9 mm (MNHN); Stn CP737, 23º03.42’S, 166º59.97’E, 350–400 m, 13 May 1993: 2 males 9.3 x 7.0, 15.6 x 10.7 mm (MNHN). BATHUS 3: stn DW830, 23º20’S, 168º01’E, 361–365 m, 29 Nov 1993: 2 females 13.0 x 9.4, 18.3 x 12.9 mm (MNHN); Stn DW838, 23º01’S, 166º50’E, 400–407 m, 30 Nov 1993: 1 female 18.2 x 13.0 mm; Stn CP847, 23º03’S, 166º58’E, 405–411 m, 1 Dec 1993: 2 females 14.2 x 10.3, 16.9 x 12.1 mm (MNHN). HALIPRO 1: stn CP877, 23º3’S, 166º59’E, 464–480 m, 31 Mar 1994: 1 male 6.4 x 4.8 mm (MNHN). BATHUS 4: stn DW927, 18º55.48’S, 163º22.11’E, 452–444 m, 7 Aug 1994: 2 males 13.4 x 9.0, 34.5 x 25.0 mm, 1 female 25.8 x 18.4 mm (MNHN). HALICAL 1: stn DW04, 18º55’S, 163º24’E, 350–365 m, 28 Nov 1994: 1 female 18.0 x 12.7 mm (MNHN). Loyalty Islands. MUSORSTOM VI: stn DW391, 20º47.35’S, 167º05.70’E, 390 m, 13 Feb 1989: 1 male 13.0 x 9.2 mm, 1 female 11.5 x 8.4 mm (MNHN); Stn DW406, 20º40.65’S, 167º6.80’E, 373 m, 15 Feb 1989: 1 male 13.0 x 9.2 mm (MNHN); Stn DW411, 20º40.60’S, 167º3.35’E, 424 m, 15 Feb 1989: 2 females 9.8 x 7.2, 19.4 x 13.2 mm (MNHN); Stn DW412, 20º40.60’S, 167º3.25’E, 437 m, 15 Feb 1989: 1 male 10.1 x 7.4 mm (MNHN); Stn DW459, 21º01.39’S, 167º31.47’E, 425 m, 20 Feb 1989: 1 female 19.1 x 13.1 mm (MNHN); Stn CP464, 21º2.30’S, 167º31.60’E, 430 m, 21 Feb 1989: 3 males 9.5 x 7.2–19.3 x 14.1 mm, 6 females 17.3 x 11.9–19.4 x 13.1 mm (MNHN); Stn DW479, 21º13.50’S, 167º54.95’E, 310 m, 22 Feb 1989: 1 female 13.0 x 9.5 mm (MNHN); Stn DW487, 21º23.20’S, 167º46.40’E, 500 m, 23 Feb 1989: 2 males 18.3 x 12.1, 18.3 x 12.5 mm, 2 females 9.2 x 6.9, 14.5 x 10.3 mm (MNHN). Chesterfield Islands- Bellona Plateau. CHALCAL 1984: stn CP8, 19º43.80’S, 158º35.25’E, 348 m, 19 Jul 1984: 1 male 18.7 x 12.4 mm (MNHN). Norfolk Ridge. SMIB 5: stn DW98, 23º01.7’S, 168º16.1’E, 335 m, 14 Sep 1989: 1 male 12.4 x 9.1 mm (MNHN). Description. Carapace sub-pentagonal, wider than long, ratio CW/CL = 1.4, surface smooth except for occasional eroded areas or small pits scattered over surface. Carapace surface without any major projections. Median rostral tooth short bluntly rounded, horizontal. Lateral rostral teeth scarcely evident. Frontal region with small central concavity. Dorsal orbital margins not elevated, mid-orbital depression only faintly marked. Protogastric region convex, mesogastric with narrow, rounded median ridge that extends posteriorly, continues after small constriction on to metagastric, cardiac, intestinal regions. Hepatic region slopes steeply to hepatic margin which stands out strongly behind orbit. Anterior branchial region with only one broad ridge (corresponding to posterior ridge) that does not quite extend to posterior epibranchial margin. Small low rounded prominence in posterior branchial region close to posterior epibranchial margin. Branchiocardiac groove with 3 small pits on each side, solitary tubercle absent. Orbital margin smooth, concave to well marked supraorbital suture. Concave suborbital margin ends in sub-acute tooth. Complete hepatic margin prominent, descending almost vertically from beneath postorbital corner; posterior edge bluntly rounded. First anterior epibranchial tooth close to hepatic projection, armed with 11 finely tuberculate teeth, initially distinct, but tending to merge, forming flattened margin near posterior epibranchial corner. Posterior epibranchial margin concave, one large tooth just behind posterior epibranchial corner. Posterior margin marked by broad blunt tubercles on each side with slightly concave margin in between. Epistome with small central depression widely separated from depressions at each corner. Sub-hepatic region deeply concave with deep open fissure at bottom; fissure running from near base of suborbital tooth to

14


MCLAY & TAN

posterior hepatic margin. Strong lamelliform ridge runs parallel to hepatic fissure, interrupted by hepatic notch lying beneath first anterior epibranchial tooth, continuing on sub-branchial area where it disappears. Cheliped-blocking mechanism involves proximal spine on posterior margin of cheliped merus meeting subbranchial spine near cheliped base. Depression on male sternites 3, 4 U-shaped, with larger tubercle at each corner. Sternites 5, 6, 7 with curved tuberculate ridges on anterior epibranchial corners decreasing in size posteriorly, preceded by small concavities. No ridges on mature females, where space is taken up by abdomen. Only sternal suture 6/7 complete in males, females.

FIGURE 6. Gonopods. Garthambrus darthvaderi sp. nov.: A, B, holotype, male 19.9 x 14.0 mm (MNHN), New

Caledonia, BIOCAL, stn DW44, 22°47’S, 167°14’E, 440–450 m, 30 Aug 1985. — Garthambrus lacunosus (Rathbun, 1906): C, D, holotype, male 30.9 x 21.8 mm (USNM 29842), Hawaiian Is, west coast of Hawaii, Kawaihae. — Garthambrus posidon Ng, 1996: E, F, male 35.3 x 23.8 mm (MNHN), Madagascar; A, C, left G1; B, D, left G2; E, right G1; F, right G2. Scale bar = 1 mm.

Eyes mobile, eyestalks granular, short, diameter same as cornea, at right angles to body axis; margin of orbit incomplete ventrally, orbital fossa deep, formed by lateral, suborbital margins Around 80% of cornea concealed when eye folded away. Antennal article 1 (urinal article) mobile, wider than long, convex; article 2 (basal article) trapezoidal, convex, fixed to epistome, suborbital margin; articles 3, 4 mobile, longer than wide; flagellum as long as articles 3, 4 combined. Medial edge of basis-ischium of third maxilliped blade-like, without setae; central longitudinal concavity present. Surface of merus densely granular; distal depressions, separated by ridge marked by one strong tubercle plus several other tubercles. Distolateral corner of endopod merus conceals end of third maxilliped exopod. Carpus, propodus, dactylus of endopod decreasing in size distally, last two articles folded under merus. REVISION OF THE CRAB GENUS GARTHAMBRUS


15

Inner margin of cheliped merus armed with 12 sub-acute tubercles of varying size; outer margin with 8 tubercles, last 3 median, curving downward from dorsal to ventral margin. Most distal tubercle largest. Cheliped carpus with one sub-acute tubercle mid-way near upper border. Outer margin of propodus armed with 5 or 6 evenly spaced, blunt tubercles; inner margin with 8 tubercles, increasing in size distally, last 4 curving towards base of dactylus. Dactylus with 3 or 4 obsolete tubercles on upper margin. Teeth on cheliped fingers weakly developed: right cheliped (crusher) gaping, with 2 teeth, left cheliped (cutter) with 3 teeth on opposing margins. Male cheliped length 2.4x CW or 3.3x CL; mature female cheliped length 1.8x CW or 2.5x CL. Ambulatory legs decrease in length posteriorly. Formula describing arrangement of tubercles on articles of each limb: P2: without tubercles; P3: merus 0/(3+1); P4 merus 0/(3+3); P5 merus 1/(3+2); all other articles without tubercles. Third abdominal segment lateral areas have prominent tubercle, central area depressed. Segments 4–6 with central ridge, scattered tubercles. Medial hook on segment 6 absent in males, females. Segments 3–5 fused in male, only suture 4/5 evident near margins. Abdominal locking mechanism present in males, immature females, sometimes in mature females, although tubercles on sternite 5, sockets on abdominal segment 6 present. Telson wider than long, tip bluntly rounded in males, females. Female gonopore circular, situated mid-way on sternite 6, not raised above sternal surface, closed by flexible cover (but non-operculate). G1 reaches anterior margin of sternite 5, narrows quickly to straight section distally, sperm aperture sub-terminal, medial, tip minutely spinose. Spinose tip occupies last 21% of G1. G2 reaches middle of sternite 4, slightly longer than G1, flagellum twisted. Proximal end of flagellum marked by small notch. Ratio of flagellum length/total length of G2 = 0.47. Ratio of length of G2/G1 = 1.28. Distribution. New Caledonia, Loyalty Is, Chesterfield Plateau and Norfolk Ridge. Etymology. The species name is derived from the sinister “Star Wars” character, “Darth Vader”, the “helmeted one”, and it alludes to the helmet-like appearance of the front of this species. Remarks. Garthambrus darthvaderi resembles G. pteromerus but differs mainly in that the hepatic tooth is absent in G. darthvaderi, but present in G. pteromerus; the carapace surface is more pitted in G. pteromerus. Also G. pteromerus has a small concavity immediately behind the orbits that is much shallower G. darthvaderi.

Garthambrus lacunosus (Rathbun, 1906) (Figs 6C, D, 12A, B) Parthenope (Platylambrus) stellata lacunosa Rathbun, 1906: 884, pl. 15 fig. 7. Parthenope (Platylambrus) lacunosa — Garth 1993: 788. Parthenope lacunosa — Garth & Davie 1995: 226, fig. 3A. Garthambrus lacunosa — Ng 1996: 156, 158. – Ng & Tan 1999: 122, 126, figs 2A–B, 3A–C, 6D–F.

Type material. HOLOTYPE: male, 30.9 x 21.8 mm (USNM 29842), Hawaiian Is, west coast of Hawaii, Kawaihae, RV Albatross, stn 4045, 20º01’45”N, 155º54’15”W, 147–198 fm (269–362 m), 8 hemp tangles gear, 11 Jul 1902. PARATYPES: 1 female 30.2 x 21.3 mm (USNM 29841), Hawaiian Is, south coast of Molokai, off Lae-OKa Laau Lighthouse, RV Albatross, stn 3835, 64º00’N, 00º13’42”W, 169–182 fm (309–333 m), 3 Apr 1902; 1 male 30.0 x 20.7 mm (USNM 29843a), Hawaiian Is, Pailolo Channel, between Maui and Molokai islands, southeast of Mokuhooniki Islet, RV Albatross, stn 4100, 21º05’30”N, 156º40’30”W, 8 hemp tangles gear, 130–151 fm (238–276 m), 23 Jul 1902; 1 female (USNM 29844) (not examined); 1 male, transferred to Stanford University (not examined; see Ng & Tan 1999), Hawaiian Is, Northwest coast of Oahu, RV Albatross, stn 4114, 154–195 fm (282–357 m). Material examined. Indonesia. KARUBAR, Kai Is, stn DW32, 5º47’S, 132º51’E, 170–206 m, 26 Oct 1991: 1 female 19.2 x 14.4 mm (MNHN-B31870).

16


MCLAY & TAN

Hawaiian Islands. Pailolo Channel, between Maui and Molokai islands, southeast of Mokuhooniki Islet, RV Albatross, stn 4100, 130–151 fms (238–276 m), 23 Jul 1902: 1 male 30.9 x 21.0 mm (USNM 29843b). Diagnosis. Carapace tuberculate, not spinose, with deep lacunae on protogastric, epibranchial and cardiac regions; supra-orbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial and cardiac regions fuse together to form smooth ridges or plates. Frontal projection short, less than one quarter carapace length. Epibranchial marginal teeth triangular, tips sharp. Mesobranchial margin without raised smooth triangular patch. Sub-orbital spine not produced, spine tip not extending beyond anterior outer corner of antennal article 2. Posterior sub-branchial region tuberculate. Cheliped merus and outer margins dentate, teeth triangular; carpus outer margin entire. Upper margins of P5 merus, carpus, propodus cristate; posterior surface of merus, carpus, propodus smooth. Distribution. Kai Is, Indonesia and Hawaiian Is. Remarks. Rathbun (1906) originally described this species as a subspecies of G. stellatus. Ng & Tan (1999) showed that it is distinct from G. stellatus (Rathbun, 1906). This species is actually very similar to G. pteromerus (Ortmann, 1893) primarily due to the less strongly tuberculate carapace dorsal surface and the presence of lamelliform cristae on the ambulatory legs. However, G. lacunosus can be easily differentiated from G. pteromerus by the strongly tuberculate sub-branchial region, which is smooth in G. pteromerus.

Garthambrus posidon Ng, 1996 (Figs 6E, F, 13A) Garthambrus posidon Ng, 1996: 159, figs 1–5. – Ng & Tan 1999: 122.

Type material. HOLOTYPE: male 66.1 x 41.6 mm, (RMNH D 42686), data after Ng (1996) (not examined), Seychelles, south of Alphonse Atoll, Tyro Seychelles Expedition 1992/93, stn 794, 7º03’S, 52º43’E, on coral rubble with poor epifauna, 480–600 m, rectangular dredge, 5–6 Jan 1993. Material examined. Madagascar. Stn P3, trawl 37, 12º51’S, 48º06.30’E, 675–705 m, A. Crosnier coll., 14 Sep 1972: 1 male 35.3 x 23.8 mm (MNHN-B31871). – Stn unknown, trawl 119, 12º50.7’S, 48º06.0’E, 750–765 m, A. Crosnier coll., 10 Oct 1974: 1 male 39.4 x 26.5 mm (MNHN-B31872). Diagnosis. Carapace surface sparsely tuberculate, not spinose, without deep lacunae; supra-orbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions not fusing together to form smooth ridges or plates. Frontal projection short, less than one quarter carapace length. Tips of epibranchial margin teeth acute. Mesobranchial margin without a raised smooth triangular patch. Suborbital spine produced, spine tip extending beyond anterior outer corner of antennal article 2. Sub-branchial region tuberculate. Cheliped merus and carpus outer margin dentate, teeth low, tips blunt. Upper margin of P5 merus, carpus and propodus tuberculate; posterior surface of merus, carpus and propodus smooth. Distribution. Seychelles and here for the first time Madagascar. Remarks. Garthambrus posidon bears some resemblance to G. poupini in the morphology of the carapace. Ng (1996) listed several other characters that can be used to differentiate these species. The CW/CL ratio in G. posidon is larger (1.5–1.6) compared with 1.3 in G. poupini. Another character is the shape of the epibranchial teeth, which are short but sharp in G. posidon, but blunt, the larger ones becoming slightly paxilliform, in G. poupini.

Garthambrus pteromerus (Ortmann, 1893) nov. comb. (Figs 7A, B, 12C, D, 22E–H) Lambrus (Parthenopoides) pteromerus Ortmann, 1893: 416, pl. 17, fig. 1. – Balss 1922: 135; 1924: 61. – Yokoya 1933: 166 (list). – Sakai 1934: 299. Parthenopoides pteromerus — Flipse 1930: 85 (list). – Sakai 1935: 72, text-fig. 6; 1936: 110, text-fig. 51.



17

Tutankhamen pteromerus — Sakai 1938: 339, pl. 41 figs 1, 2. – Miyake 1961: 17. – Sakai 1965: 97, pl. 44 fig. 4. – Takeda & Miyake 1969: 473, fig. 1. – Miyake 1983: 53, 211 (list), pl. 18. – Cai et al. 1994: 583. Parthenope (Platylambrus) validus forma intermedius — Dong et al. 1988: 88, fig. 80. Not Lambrus intermedius Miers, 1879a.

Material examined. China: unknown location, 1 male 19.3 x 13.7 mm (ZRC). Taiwan. TAIWAN 1: stn CP58, 24º35.1’N, 122º5.8’E to 24º33.3’N 122º05.6’E, 221–254 m, dense crinoids, 4 Aug 2000: 1 male 22.2 x 15.3 mm (ZRC 2001.2225); Same data as previous: 1 male 16.4 x 11.6 mm, 1 female 11.4 x 8.4 mm (MNHN). TAIWAN 2: stn 2, waters off Kaohsiung, 200 m, 9 Apr 2002: 1 male 13.1 x 10.0 mm, 1 female 20.0 x 14.4 mm (MNHN) Japan.: unknown location, 17 Mar 1967, 1 female 18.2 x 13.7 mm (SFM) (TS00383); Sagami Bay, Hatsushima bei Atami, Kanagawa Ken, dredge, forschungsschiff der Uni Yokohama, no date: 1 male 20.9 x 15.5 mm. Albatross: stn 4807, Cape Tsiuka, from Hakodata, Japan to Ebisu, Sado I., Sea of Japan (via Tsugaru Strait), 81 m, 16 Jul 1906: 2 males 19.1 x 14.1, 21.9 x 16.2 mm (USNM 50912); Stn 4894, Ose Sakai Strait, 10 to20 miles SW of Goto Is, Eastern Sea, 174 m, 9 Aug 1906: 1 female, 16.9 x 12.2 mm (USNM 50910). Danish Pacific Expedition, 1914–1915: 23 miles northwest, 3/4 miles west of Goto (or Osesaki), 32º49’N, 128º14’E, 210 m, 14 May 1914: 1 ovig. female 14.0 x 10.3 mm (ZMUC); Off Misaki, 80–100 fm (146-183 m), 19 Jun 1914: 1 male 33.1 x 22.4 m. (ZMUC). Bungo Strait, Shikoku I., Tosa Bay, T. & K. Sakai coll., 16 Nov 1958: 1 male 31.8 x 19.9 mm (USNM 120717); Kii Peninsula, west of Shionomisaki, 33º26.72’N, 135º39.20’E, 180 m, 16 Apr 1997: 2 males 9.8 x 8.1, 15.9 x 11.6 mm, 1 female 18.1 x 12.9 mm (ZRC). Indonesia. KARUBAR: stn DW32, Kai Is, 05º47’S, 132º51’E, 170–206 m, 26 Oct 1991: 1 female 19.2 x 14.4 mm (MNHN). Philippines. MUSORSTOM 1, stn 35, 13º59.0’N, 120º18.5’E, 186–187 m, 23 Mar 1976: 1 male 29.5 x 19.0 mm (MNHN-B31873). MUSORSTOM 2, stn DG32, 13º40’N, 120º54’E, 192–220 m, 24 Nov 1980: 1 female 16.7 x 12.8 mm, 1 ovig. female 22.9 x 14.6 mm (MNHN-B31874). Visayas, Bohol, Panglao I., off Panglao town, Balicasag I.: about 200–300 m, tangle nets, Dec 2000: 1 male 27.6 x 18.3 mm (ZRC). – about 200–300 m, tangle nets, Dec 2000: 1 male 20.1 x 14.1 mm (ZRC). – about 50–500 m, in tangle nets, 28 Nov 2001: 10 males (ZRC). Redescription. Carapace sub-pentagonal, wider than long, CW/CL = 1.35–1.55, surface finely granular with some eroded/pitted areas, especially on prominent parts of carapace. Median rostral tooth blunt, narrowing anteriorly, horizontal; lateral teeth hardly produced, edge eroded to accommodate antennules. Frontal region concave, dorsal orbital region slightly elevated with small mid-way eroded area. Protogastric area elevated, pitted, eroded, with pair of faint rounded tubercles. Mesogastric region with broad pitted median ridge topped by prominent tubercle. Ridge continues through metagastric area at lower level, faint tubercle sometimes present. Cardiac region has narrow median ridge with prominent rounded tubercle, weak tubercle present in intestinal area as ridge descends towards posterior margin. Anterior branchial region with diagonal ridge ending in low rounded tubercle behind posterior epibranchial corner. Posterior branchial region with distinct narrow tubercle which overhangs posterior epibranchial margin. Three pits in branchiocardiac groove, also faint tubercle. Total number of carapace tubercles 10. Orbital margin finely granular, strongly concave posteriorly to well marked supraorbital suture. Suborbital concave margin ends in sub-acute tooth with large gap between tooth, lateral rostral tooth. Posterior corner of hepatic margin produced, with small tubercle on posterior edge. First anterior epibranchial tooth immediately above hepatic notch followed by 8–10 distinct teeth. Anterior epibranchial margin laciniate, posterior epibranchial corner flange-like, with, small tooth. All anterior epibranchial teeth tend to be curved upwards. Posterior epibranchial margin with 2 teeth posterior to epibranchial corner, first larger. Posterior margin with 3 blunt teeth, lateral ones larger.

18


MCLAY & TAN

FIGURE 7. Gonopods. Garthambrus pteromerus (Ortmann, 1893): A, B, male 31.8 x 19.9 mm (USNM 120717), Japan,

Buno Straits, Shikoku I. — Garthambrus stellatus (Rathbun, 1906): C, D, holotype, male 48.6 x 32.8 mm (USNM 29839), Hawaiian Is, south coast, Oahu. A, C, left G1; B, D, left G2. Scale bar = 1 mm.

Epistome T-shaped, central region with adjacent circular concavities separated by ridge; lateral concavities lack complete encircling ridge. Subhepatic region concave with hepatic fissure extending forward towards corner of buccal frame. Fissure surrounded by tubercles. Strong ridge begins at corner of buccal frame, below hepatic fissure, after interruption by distinct notch beneath first anterior epibranchial tooth, extends posteriorly on to sub-branchial region. Cheliped-blocking mechanism consists of proximal meral spine on cheliped meeting strong sub-branchial spine. Surface of sternites 3, 4 have U-shaped depression with large tubercle at each corner. Sternites 5 –7 with small slightly projecting tuberculate ridges each preceded by small depression. Only sternal suture 6/7 complete in both sexes. Eyes mobile, eyestalks granular, short, diameter same as cornea, articulate at right angles to body axis; margin of orbit incomplete ventrally, orbital fossa deep, formed by lateral, suborbital margin, approximately 80% of cornea concealed when eye folded away. Antennule article 1 mobile, 6-sided; article 2 much longer than wide, inserted medially, folded away at an oblique angle; article 3 much longer than wide; articles 3, 4 normally kept folded away in antennular fossa. Antennal article 1 (“urinal article”) mobile, wider than long, convex; article 2 ( “basal article”) trapezoidal, convex, fixed to epistome, suborbital margin; articles 3, 4 mobile, longer than wide; flagellum as long as articles 3, 4 combined. Third maxilliped basis-ischium with longitudinal central depression, blade-like medial margin. Merus with dense coarse granules obscuring adjacent depressions. Distolateral corner of merus covers distal end of exopod. Carpus, propodus, dactylus of endopod decrease in size distally, last 2 articles folded under merus. Cheliped length in males 2.7 x CW or 4.0 x CL. Corresponding ratios for females 1.9, 2.6. Inner margin of merus with 17 well developed subacute tubercles, with many smaller ones interspersed. Outer meral margin with 10 or 11 similar tubercles with, mid-way, a group of 4 tubercles curving down from dorsal to ventral surface, but these are not involved with the cheliped-blocking mechanism. Carpus with 7 tubercles of varying size on inner margin, 3 or 4 on the surface. Outer margin of propodus with 8 to 10 tubercles (4 larger evenly REVISION OF THE CRAB GENUS GARTHAMBRUS


19

spaced tubercles with smaller ones in between), outer margin with 12 tubercles of various sizes, last 5 curving up toward base of dactylus. Upper surface of dactylus with 3 or 4 tubercles decreasing in size distally. Right cheliped (crusher) with essentially obsolete teeth, left (cutter) with 3 very weak teeth. Length of ambulatory legs decreases posteriorly. Formula for leg tubercles: P2: no tubercles on any articles; P3: merus 0/(0 + 3), none on carpus, propodus; P4: merus 0/(3 + 3), none on carpus, propodus; P5: merus 0/(3 + 3), carpus 0/0, propodus 0/3. Most leg margins have continuous crest except for meral segments where crests interrupted to produce teeth-like features. Dactyli of P2–P5 shorter than propodi. Abdominal segment 3 with lateral ridge on each side, central depression, while segments 4-6 have low central median ridge. Segments 3-5 fused in male, sutures only indicated by marginal notches. Acute medial hook present on segment 6. Abdominal locking mechanism complete, working in males, females. Telson triangular, wider than long, tip narrowly rounded. Tip more pointed in female with telson occupying most of fourth sternite. Male G1 reaches mid-way of sternite 5 in situ, sub-terminal sperm aperture opens medially, surface minutely spinose over distal 27% of length. G2 reaches mid-way of sternite 4 in situ, tip acute, twisted. G2 made up of two sections, proximal calcified section followed by horny flexible, twisted flagellum 0.48 of length. Beginning of flagellum marked by presence of small notch, sudden reduction in diameter of gonopod. Ratio of G2/G1 = 1.4. Female gonopore in middle of sternite 6, only slightly raised above sternal surface, subcircular in shape, covered by flexible layer. Distribution. Japan and China, and now for the first time from. Taiwan, Philippines and Indonesia. Remarks. The generic placement of Lambrus (Parthenopoides) pteromerus Ortmann, 1893, has been the subject of considerable debate. This species is certainly not related to Parthenopoides Miers, 1879b (type species: Lambrus massena Roux, 1830), due to the very different carapace shape and the considerably longer chelipeds. Sakai (1938) placed it in Tutankhamen Rathbun, 1925 (type species: Mesorhoea cristatipes A. Milne-Edwards, 1878), based mainly on the carapace shape and the size of the basal antennal segment (antennal article 2) and synonymised G. lacunosus with it. Garth (1993) refuted the synonymy because G. lacunosus does not possess a lamellar ridge that lines the afferent respiratory channels, which is present in L. (P.) pteromerus. Ng (1996) pointed out that the restriction of Tutankhamen to the Atlantic Ocean, the different carapace dimensions and gonopod structure makes it very unlikely that the two species are congeneric. He noted that it is very close to Garthambrus but due to a lack of specimens hesitated to place it in Garthambrus. The examination of specimens of L. (P.) pteromerus and of the type species of T. cristatipes allowed us to conclusively place it in Garthambrus. Some generic characters were also clarified. Balss (1922) commented that G. pteromerus is “scheint der L. (Parthenolambrus) exilipes Rathbun, 1893 von Californien und den Galapagos-Inslen zu sein” [i.e. G. pteromerus “appears to be the same as L. (Parthenolambrus) exilipes from California and the Galapagos Islands”]. Sakai (1935) identified his material as Parthenopoides pteromerus but commented that they were similar to G. lacunosus. It is clear from his figure, however, that they belonged to G. pteromerus. The identification by Dong et al. (1988) of Parthenope (Platylambrus) validus forma intermedius from the East China Seas is incorrect and should be referred to G. pteromerus. All three specimens from the Albatross Expedition were originally identified by M. Rathbun as Parthenope (Platylambrus) stellata lacunosa Rathbun, 1906. These old records were apparently never published by Rathbun.

Garthambrus stellatus (Rathbun, 1906) (Figs 7C, D, 13B) Parthenope (Platylambrus) stellata Rathbun, 1906: 884 (part), pl. 15, figs 1, 2. – Garth 1993: 786, figs 3, 4. Parthenope (Platylambrus) stellatus — Serène 1968: 60. Parthenope stellata — Garth & Davie 1995: 225, fig. 2B.

20


MCLAY & TAN

Garthambrus stellata — Ng, 1996: 158. – Ng & Tan 1999: 122, figs 1A–D, 6A–C; Tan et al. 1999: 199, figs 5, 13d. Garthambrus stellatus — Ng et al., 2008: 130 (list). Not Parthenope (Platylambrus) stellata Rathbun, 1906 — Edmondson 1951: 213, fig. 18 [= Pseudolambrus calappoides (Adams & White, 1849)].

Type material. HOLOTYPE: 1 male 48.6 x 32.8 mm (USNM 29839), Hawaiian Is, south coast of Oahu, 435–461 m, RV Albatross, stn 3811, 27 Mar 1902. PARATYPE: male 32.9 x 23.1mm (USNM 29840), Hawaiian Is, Albatross, stn 4045, Hawaii, Kawaihae, 20º01'45"N, 155º54'15"W, 269–362 m, 8 hemp tangles gear, 11 Jul 1902. Material examined. Philippines. Bohol, Panglao I., off Panglao town, Balicasag I., 50–500 m, in tangle nets, 28 Nov 2001: 1 male 45.9 x 31.3 mm (ZRC). Taiwan. Nangfangau, Ilan County, 150 m, trawler, coll. J.-F. Huang, 17 Dec 1991: 1 ovig. female 29.8 x 20.3 mm (NKIMT). New Caledonia. BIOCAL: stn DW66, 24º5’S, 168º22’E, 505–515 m, 3 Sep 1985: 1 female 6.4 x 5.4 mm (MNHN). MUSORSTOM IV: stn 215, 22º55.7’S, 167º17.0’E, 485–520 m, 29 Sep 1985: 1 male 14.5 x 10.7 mm (MNHN). CHALCAL II: stn DW74, 24º40.36’S, 168º38.38’E, 450 m, 29 Oct 1986: 1 male 17.0 x 12.7 mm (MNHN). – Stn DW75, 24º39.31’S, 168º39.67’E, 600 m, 29 Oct 1986: 1 male 11.6 x 9.3 mm, 1 female 13.2 x 10.4 mm (MNHN). SMIB 3: stn 13, 23º37.5’S, 167º41.6’E, 448 m, 25 May 1987: 1 male 21.6 x 16.0 mm (MNHN). AZTEQUE: stn 6, 23º37950’S, 167º42.50’E, 425–470 m, 14 Feb 1990: 1 male 24.9 x 18.7 mm, 1 female 32.3 x 22.9 mm (MNHN). BERYX 11: stn CP07, 24º55’S, 168º21’E, 510–550 m, 15 Oct 1992: 1 female 14.0 x 9.9 mm (MNHN). SMIB 8: stn DW167, 23º38.1’S, 168º43.1’E, 430–452 m, 29 Jan 1993: 1 female 45.6 x 32.2 mm (MNHN). – Stn DW169, 23º37.7’S, 167º42.5’E, 447–450 m, 29 Jan 1993: 1 female 46.0 x 32.2 mm (MNHN). – Stn DW187, 23º17.7’S, 168º05.6’E, 390–540 m, 31 Jan 1993: 1 female 30.7 x 21.1 mm (MNHN). BATHUS 3: stn CP811, 23º41.42’S, 168º15.50’E, 283–408 m, 28 Nov 1993: 1 female 51.8 x 35.1 mm (MNHN). – Stn DW830, 23º20’S, 168º01’E, 316–365 m, 29 Nov 1993: 1 female 9.2 x 7.3 mm (MNHN). – Stn DW 838, 23º01’S, 166º56’E, 400–402 m, 30 Nov 1993: 1 female, 20.7 x 14.0 mm. BATHUS 4, stn CP928, 18º54.72’S, 163º23.73’E, 452–420 m, 7 Aug 1994: 1 ovig. female 35.5 x 26.6 mm (MNHN). – Stn DW929, 18º51.55’S, 163º23.27’E, 502–516 m, 7 Aug 1994: 1 male 20.0 x 14.1 mm, 1 female 18.6 x 14.1 mm (MNHN). MUSORSTOM 6: Loyalty Is, stn DW410, 20º38.50’S, 167º6.65’E, 490 m, 15 Feb 1989: 1 female 47.6 x 31.3 mm (MNHN). Vanuatu. MUSORSTOM 8: stn DW 986, 19º20.57’S, 169º31.48’E, 602–648 m, 23 Sep 1994: 1 female 7.8 x 6.6 mm (MNHN-B31875). French Polynesia. Tuamotu Archipelago. Mururoa: stn D14, 21º05.45’S, 139º02.50’W, 319 m, SMCB coll., 24 May 1990: 1 male 62.1 x 41.0 mm (MNHN MP B-22426). Marquesas Islands. MUSORSTOM 9: Ua Pou, stn DW1148, 9º18.9’S, 140º06.3’W, 300 m, 22 Aug 1997: 1 female 9.8 x 7.9 mm (MNHN-B31876); Mutu One, Hatutaa, stn CP1282, 7º51.7’S, 140º30.6’W, 416–460 m, 7 Sep 1997: 1 female 52.6 x 35.7 mm (MNHN-B31877); Nuku Hiva I., stn CP1306, 8º55.2'S, 140º14.8'W, 283–448 m, 10 Sep 1997: 1 male 58.0 x 39.1 mm (MNHN-B31878). Hawaiian Islands. Oahu, off Pearl Harbour, dredge spoil site, found on sediment bottom in vicinity of outcrop, Hurl Makalii Dive, stn 82–105, 200 fms (366 m), D. M. Devaney & B. Bartko coll., 1 Sep 1982: 1 male 69.2 x 45.6 mm (ZRC 1997.441).



21

Diagnosis. Carapace dorsal surface tuberculate, tubercles paxilliform to stellate, without lacunae; supraorbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions not fusing together to form smooth ridges or plates. Frontal projection short, less than one quarter length of carapace. Epibranchial margin teeth with sharp tips. Mesobranchial margin without raised, smooth, triangular patch. Sub-orbital spine produced, spine tip extending beyond anterior outer corner of antennal article. 2 Sub-branchial region densely tuberculate. Cheliped merus and carpus outer margins dentate, teeth tips sharp. Upper margins of P5 merus, carpus and propodus spinose; posterior surface of merus, carpus and propodus spinose. Distribution. French Polynesia, Hawaiian Is and for the first time Vanuatu, Philippines and Taiwan. Remarks. The only species of Garthambrus that G. stellatus bears some resemblance to are G. poupini, G. allisoni and G. cidaris but in these species the density of tubercles is much lower and their CW/CL ratio is smaller. G. stellatus is also similar to Hispidolambrus mironovi in having spinose ambulatory legs, a character which is not found in other Garthambrus species, but it can be differentiated from H. mironovi by not having a spinose carapace surface. In addition, G. stellatus is now known only from the western Pacific Ocean, whereas H. mironovi appears to be restricted to the eastern Pacific Ocean. Variation in G. stellatus has been discussed in some detail by Ng & Tan (1999). Edmondson (1951) examined two specimens from the Hawaiian Is (BPBM S 5508) and identified them as belonging to this species, however, examination of these specimens shows that they belong instead to Pseudolambrus calappoides (Adams & White, 1849). Their lateral teeth are placed much more posteriorly than G. stellatus, about in the same line as the posterior margin and are more lobate. In addition, the teeth on the cheliped outer margins are less sharp than in G. stellatus. The spines on the ambulatory legs are finer, more numerous, and the base of the spines are also not as broad as those seen in G. stellatus. The group of ‘stellate tubercles’ depicted by Edmondson (1951: Fig. 18b), is definitely not stellate but granular.

Garthambrus tani Ahyong, 2008 (Figs 8A, B, 14)

FIGURE 8. Gonopods. Garthambrus tani Ahyong, 2008: A, B, male 28.5 x 21.2 mm (MNHN), New Caledonia,

VAUBAN, stn CB113, 500 m, 12 Apr 1978. — Garthambrus undulatus sp. nov.: C, D, holotype, male 44.4 x 29.0 mm (MNHN), New Caledonia, VOLSMAR, stn DW30, 22°17.0’S, 171°17.7’E, 550 m, 5 Jun 1989. A, C, left G1; B, D, left G2. Scale bar = 1 mm.

22


MCLAY & TAN

FIGURE 9. Garthambrus poupini (Garth, 1993): A, male 39.4 x 29.9 mm (MNHN B 22420), French Polynesia, Tuamotu Archipelago, Fangataufa. — Garthambrus allisoni (Garth, 1993): B, female 14.1 x 11.0 mm (MNHN B 22421), French Polynesia, Bora Bora.



23

FIGURE 10. Garthambrus cidaris (Garth & Davie, 1995): A, holotype, female 52.8 x 36.1 mm (QM W 16086),

Australia, northeast Queensland. — Garthambrus complanatus (Rathbun, 1906): B, lectotype, male 17.3 x 12.7 mm (USNM 29845a), Hawaiian Is, Kauai.

24


MCLAY & TAN

FIGURE 11. Garthambrus darthvaderi sp. nov. : holotype, male 19.9 x 14.0 mm (MNHN), New Caledonia, BIOCAL,

stn DW44, 22°47’S, 167°14’E, 440–450 m, 30 Aug.1985. A, dorsal view; B, front view; C, side view. Tutankhamen sp — Clark & O’Shea 2001: 15. – Martin & Haney 2005: 451, 497. Not Tutankhamen Rathbun, 1925. Garthambrus tani Ahyong, 2008: 55, figs 25–27.

Types examined. PARATYPES: 1 male, 17.8 x 13.4 mm, 1 ovig. female, 11.7 x 8.2 mm (NIWA 34979), off Curtis I., Kermadec Is, stn K840, 30°17.59’S, 178°25.30’W, 398–412 m, 28 Jul 1974. Material examined. New Caledonia. VAUBAN, stn DC22 (sample also registered as CB113), 22°59.00S, 167°17.00E, 540–545 m, 12 Apr 1978: 1 male 28.5 x 21.2 mm, 1 female, 22.8 x 16.3 mm (MNHN-B31879). MUSORSTOM IV: stn 197, 18º51.3’S, 163º21.0’E, 550 m, 20 Sep 1985: 1 male 25.6 x 19.3 mm, 1 female 18.5 x 14.2 mm (MNHN-B31880); Stn 215, 22º55.7’S, 167º17.0’E, 485–520 m, 29 Sep 1985: 1 male 22.0 x 16.4 mm (MNHN-B31881); Stn 216, 22º59.5’S, 167º22.0’E, 490–515 m, 29 Sep 1985: 1 female 21.0 x 15.1 mm (MNHN-B31882). BIOCAL: stn DW66, 24º55’S, 168º22’E, 505–515 m, 3 Sep 1985: 1 female 7.2 x 5.7 mm (MNHN). SMIB 2: stn DW11, 22º57.1’S, 167º18.3’E, 475–500 m, 18 Sep 1986: 1 male 25.9 x 18.8 mm (MNHN). CHALCAL II: stn DW 72, 24º54.50’S, 168º22.30’E, 527 m, 28 Oct 1986: 1 male 22.7 x 16.6 mm, 1 female 7.4 x 5.9 mm (MNHN); Stn DW73, 24º39.9’S, 168º38.10’, 573 m, 29 Oct 1986: 1 male 15.4 x 11.4 mm, 3 females 7.4 x 5.8–14.2 x 10.5 mm (MNHN); Stn DW74, 24º40.36’S, 168º38.38’E, 650 m, 29 Oct REVISION OF THE CRAB GENUS GARTHAMBRUS


25

1986: 4 males 11.1 x 8.7–17.0 x 12.7 mm, 5 females 10.5 x 8.0–15.1 x 11.5 mm (MNHN); Stn DW75, 24º39.31’S, 168º39.67’E, 600 m, 29 Oct 1986 : 5 males 11.3 x 8.9–17.7 x 12.8 mm, 4 females 10.0 x 7.3–14.5 x 11.3 mm (MNHN); Stn DW76, 23º40.5’S, 167º45.2’E, 470 m, 30 Oct 1986: 3 females 17.4 x 12.8–22.7 x 16.4 mm (MNHN); Stn DW77, 23º38.35’S, 167º42.68’E, 435 m, 30 Oct 1986: 1 female 10.7 x 8.1 mm (MNHN). SMIB 3: stn DW01, 24º55.7’S, 168º21.8’E, 520 m, 20 May 1987: 2 males 15.9 x 12.0, 18.8 x 13.6 mm (MNHN); Stn DW02, 24º53’S, 168º22’E, 530-537 m, 20 May 1987: 1 male 25.6 x 19.0 mm, 1 female 16.3 x 11.7 mm (MNHN). SMIB 4: stn DW39, 24º56.2’S, 168º21.5’E, 560 m, 7 Mar 1989: 1 male 18.0 x 13.0 mm, 1 female 36.4 x 24.2 mm (MNHN). BERYX 11: stn CP08, 24º54’S, 168º21’E, 540–579 m, 15 Oct 1992: 1 male 17.1 x 13.0 mm (MNHN); Stn DW10, 24º53’S, 168º21’E, 565–600 m, 15 Oct 1992: 5 males 6.9 x 5.8–20.2 x 15.0 mm, 5 females 6.9 x 5.8–13.3 x 10.4 mm (MNHN); Stn DW27, 23º37’S, 167º41’E, 460–470 m, 18 Oct 1992: 1 female 18.1 x 14.0 mm (MNHN); Stn DW38, 23º38.5’S, 167º39.0’E, 550–690 m, 19 Oct 1992: 1 female 19.4 x 15.1 mm (MNHN). SMIB 8: stn DW146, 24º55.2’S, 168º21.7’E, 514–522 m, 27 Jan 1993: 1 male 11.6 x 8.8 mm (MNHN); Stn DW148, 24º55.1’S, 168º21.6’E, 510 m, 27 Jan 1993: 1 female 10.1 x 7.7 mm (MNHN); Stn DW 149, 24º54.9’S, 168º21.8’E, 508–510 m, 27 Jan 1993: 2 males 10.1 x 7.7, 10.3 x 8.4 mm, 2 females 7.0 x 5.5, 10.0 x 7.3 mm (MNHN); Stn DW153, 24º55.5’S, 168º21.3’E, 547–560 m, 27 Jan 1993: 1 male 20.2 x 14.9 mm (MNHN); Stn DW164, 24º49.0’S, 168º08.7’E, 300–350 m, 28 Jan 1993: 1 male 12.6 x 9.3 mm, 1 female13.8 x 10.7 mm (MNHN). BATHUS 2: stn DW720, 22º51.62’S, 167º16.40’E, 530–541 m, 11 May 1993: 1 ovig. female 22.2 x 16.4 mm (MNHN); Stn CP735, 23º01.77’S, 166º56.10’E, 530–570 m, 13 May 1993: 1 male 19.9 x 14.7 mm (MNHN). BATHUS 3: stn CP833, 23º03’S, 166º58’E, 441–444 m, 30 Nov 1993: 1 male 11.2 x 8.8 mm (MNHN). HALIPRO 1: stn CP877, 23º3’S, 166º59’E, 464–480 m, 31 Mar 1994: 1 male 10.3 x 8.1 mm (MNHN). SMIB 10: stn DW206, 24º56’S, 168º21’E, 555–548 m, 10 Jan 1995: 1 male 14.5 x 10.6 mm (MNHN). Description. Carapace wider than long, ratio CW/CL = 1.3, sub-pentagonal, covered with fine, rounded granules. Median rostral tooth narrowing anteriorly, blunt tip bent slightly upwards; lateral rostral teeth truncate. Frontal region centrally concave. Dorsal orbital margin slightly swollen, interrupted by small depression. Protogastric region convex, bearing 2 distinct tubercles near mid-line. Meso-, metagastric regions with narrow medial interrupted ridge, but no tubercles. Cardiac region slightly pitted, eroded with prominent blunt posterior tubercle. Intestinal region with broad blunt tubercle, which may be bifid, behind cardiac tubercle. Anterior branchial region dominated by broad posterior diagonal ridge not reaching posterior epibranchial margin but ends in prominent blunt tubercle. Ridge may have some eroded areas. Posterior branchial region has prominent tubercle overhanging posterior epibranchial margin. Three pits in branchiocardiac groove but no solitary tubercle. Eight carapace tubercles. Orbital margin finely granular, very concave to distinct supraorbital suture. Suborbital margin ends in subacute tooth. Posterior corner of hepatic margin projecting, with small tubercle. First anterior epibranchial tooth close to hepatic border, followed by 10 distinct blunt teeth which tend to decrease in size posteriorly. Posterior epibranchial corner is flange-like. Anterior epibranchial teeth tend to be curved upward. Posterior epibranchial margin slightly concave, single distinct tooth behind posterior epibranchial corner. Posterior margin with 3 well developed, blunt teeth, one at each corner, one in middle. Epistome T-shaped, shallow central depression separated from lateral depressions by narrow ridge on each side. Subhepatic region concave with deep fissure running from corner of buccal frame towards first anterior epibranchial tooth. Cheliped-blocking mechanism involves large proximal meral spines meeting spine on sub-branchial area. Sternites 3, 4 of males with shallow V-shaped area impressed upon them with large tubercle at each corner, following sternites without ridges developed at lateral corners. In females these areas are taken up by abdomen. Only thoracic suture 6/7 complete.

26


MCLAY & TAN

Eyes mobile, eyestalks granular, short, diameter same as cornea; margin of orbit incomplete ventrally, orbital fossa deep, formed by lateral, suborbital margin, around 80% of cornea concealed when eye is folded away. Antennular article 1 mobile, 6-sided; article 2 much longer than wide, inserted medially, folded away at an oblique angle; article 3 much longer than wide; articles 3, 4 normally kept folded away in antennular fossa.

FIGURE 12. Garthambrus lacunosus (Rathbun, 1906): A, B, holotype, male 30.9 x 21.8 mm (USNM 29842), Hawaiian

Is, west coast of Hawaii, Kawaihae (after Ng & Tan 1999: 2A). — Garthambrus pteromerus (Ortmann, 1893): C, holotype, M 36.8 x 25.6 mm (MZS 914), Japan, Sagami Bay (photo: T. Komai) (scale bar = 10 mm); D, male 31.8 x 20.1 mm (USNM 1207170). Japan, Bungo Strait, Shikoku. A, C, carapace, dorsal view; B, D, carapace, lateral ventral view.

Antennal article 1 (“urinal article”) mobile, wider than long, convex; article 2 (often called “basal article”) trapezoidal, convex, fixed to epistome, suborbital margin; articles 3, 4 mobile, longer than wide; flagella as long as articles 3, 4 combined. Basis-ischium of third maxilliped with blade-like medial margin which is sinuous in part. Depressions on merus separated by ridge which has at least one large, several small tubercles. Disto-lateral corner of merus covers distal end of exopod, bears small tubercle. Only carpal article of palp exposed. Inner border of cheliped merus has 9 blunt tubercles with many smaller ones interspersed; outer border has 8–10 subacute tubercles with, median group of 3 tubercles curving down from upper to lower surface, most distal tubercle largest, most acute. Cheliped carpus has one prominent subacute median spine. Outer border of propodus has 8 or 9 irregular tubercles; inner border with 8 tubercles, last 5 curving up toward base of dactyl. Dactyl with two or three small tubercles decreasing in size distally. Right cheliped a crusher; left a cutter. Walking legs decrease in length posteriorly. Ornamentation on legs as follows: P2: merus 4/(1 + 0); P3: merus 4/(4 + 3); P4: merus 5/(4 + 3); P5: merus 7(3 + 3). Crest-like ridges on first 3 articles of P2 to P5, but on



27

meri these sometimes interrupted, broken into flattened regions, so that there can be toothed, crested regions on same article. Dactyli shorter than propodi. Lateral parts of third abdominal segment have small tubercle while central part is depressed. Fourth to sixth segments have central ridge. Third to fifth segments fused in male, only suture 4/5 evident near margins. Small median tubercle on segment 6 in male, absent in female. Abdominal locking mechanism effective in male, but in mature females although button, socket present, abdomen too broad, convex to work effectively. Telson wider than long, tip truncate in male more rounded in female. Telson of mature female covers most of sternite 4.

FIGURE 13. Garthambrus posidon Ng, 1996: A, male 35.3 x 23.8 mm (MNHN), Madagascar, stn P3. —Garthambrus

stellatus (Rathbun, 1906): B, holotype, male 48.6 x 32.8 mm (USNM 29839), Hawaiian Is, south coast, Oahu (after Ng & Tan 1999: fig. 1A).

28


MCLAY & TAN

G1 reaches anterior border of sternite 5 in situ, narrows quickly to straight section, sperm aperture opens medially, tip has many very small, acute spines directed proximally. Spines cover last 14% of length of G1. G2 in situ slightly longer than G1, flagella twisted, occupying 52% of length. Transition from calcareous proximal section to flexible flagella not marked by notch. Ratio of length of G2/G1 = 1.3. Female gonopore mid-way on sternite 6, oval in shape, lips raised above sternal surface, hinged laterally, sealed by flexible cover. Distribution. Known from New Caledonia, Kermadec Is and New Zealand.

FIGURE 14. Garthambrus tani Ahyong, 2008: male 28.5 x 21.2 mm (MNHN), New Caledonia, VAUBAN, stn CB113,

500 m, 12 Apr 1978. A, dorsal view; B, front view; C, side view

Remarks. This species was recently described by Ahyong (2008) from the Tumokemoke Seamount and from Curtis I., Kermadec Is, who had corresponded with us with regards to the new species (in manuscript), but considered that his specimens from New Zealand were different from our material. He believed that the key difference was that the New Zealand specimens had stellar paxillate carapace tubercles rather than the granulate tubercles typically seen in New Caledonia, but the variation seen in our much larger sample encompasses the New Zealand specimen. We are convinced that it belongs to the same species found in New Caledonia, so Ahyong’s name has priority. Some of the features included in the present study of Garthambrus were not given by Ahyong (2008) so for the sake of consistency we include our description here. Garthambrus tani is the first parthenopid recorded from New Zealand. Garthambrus tani bears some resemblance to G. stellatus in that both species have well-defined teeth on the upper margin of the ambulatory legs and the epibranchial teeth is distinct and pointed at the tips.



29

Garthambrus tani can be differentiated from G. stellatus in that some of the teeth on the upper margin of the ambulatory legs are fused with adjacent members. In G. stellatus, the teeth are always distinctively separated. In addition, G. stellatus has a densely tuberculate carapace, but the carapace is less tuberculate in G. tani.

Garthambrus undulatus sp. nov. (Figs 8C, D, 15) Type material. HOLOTYPE: male 44.4 x 29.0 mm (MNHN-B31867), New Caledonia, VOLSMAR, stn DW30, 22º17.0’S, 171º17.7’E, 550 m, 5 Jun 1989. PARATYPES: male 41.3 x 27.3 mm (MNHN-B31868), New Caledonia, CHALCAL II, stn DW72, 24º54.50’S, 168º22.30’E, 527 m, 28 Oct 1986; 1 male 19.1 x 13.4 mm (MNHN-B31869), SMIB 8, stn DW151, 24º53.4’S, 168º21.4’E, 530–547 m, 27 Jan 1993. Material examined. See type material. Description. Carapace sub-pentagonal, wider than long, surface undulating, minutely granular with some eroded areas. Median rostral tooth elongated, blunt, deflexed but slightly curving upwards near tip. Lateral rostral teeth truncated. Frontal region slightly concave, supraorbital margin slightly elevated. Protogastric region with pair of prominent, blunt tubercles behind eroded area. Mesogastric region with broad median ridge that extends to metagastric region. Hepatic region with 2 eroded areas behind orbits. Cardiac region with 2 blunt tubercles in line, separated by eroded area. Posterior diagonal ridge on anterior branchial area, with prominent sub-acute tubercle as dominant feature, anterior diagonal ridge scarcely evident. Posterior branchial area with sub-acute tubercle; branchiocardiac groove well marked by series of 3 pits. Total of 8 prominences on carapace. Supraorbital margin minutely granular; strongly concave to well marked supraorbital suture. Suborbital margin ends in prominent tooth. Margins of orbits fringed with short setae. Hepatic margin with well developed, blunt posterior tooth with smaller tooth on posterior margin, small blunt tooth before notch. Anterior epibranchial margin with 11 or 12 blunt teeth of varying size, small granules in between. Last anterior epibranchial tooth long, curved upwards, bifid. Posterior epibranchial margin concave with tooth near posterior epibranchial corner. Tubercle on posterior branchial region overhangs margin. Posterior margin concave at each corner, with prominent sub-acute tubercle. Epistome T-shaped, mostly flat except for depressed median area. Subhepatic region concave with fissure almost completely covered by granules. Pterygostomial area slightly concave, minutely granular. Subbranchial ridge not well developed. Cheliped-blocking mechanism involves stout proximal spine on posterior margin of merus, against large sub-branchial spine near base of cheliped. Depression on sternites 3, 4 Vshaped. Corners on sternite 4 depression marked by large tubercle with several smaller ones. Anterior epibranchial corners of sternites 5–7 with slightly raised, tuberculate ridges preceded by slight depression. Only sternal suture 6/7 is complete. Eyes mobile, eyestalks granular, short, diameter same as cornea, articulated at right angles to body axis; margin of orbit ventrally incomplete, orbital fossa deep, formed by lateral, suborbital margin, around 80% of cornea concealed when eye folded. Antennular article 1 mobile, 6-sided; article 2 much longer than wide, inserted medially, folded at oblique angle; article 3 much longer than wide; articles 3, 4 normally kept folded in antennular fossa. Antennal article 1 (“urinal article”) mobile, wider than long, convex; article 2 (“basal article”) trapezoidal, convex, fixed to epistome, suborbital margin; articles 3, 4 mobile, longer than wide; flagellum as long as articles 3, 4 combined. Medial edge of third maxilliped basis-ischium knife-like, meeting its opposite in mid-line. Longitudinal median concavity on basis-ischium. Merus wider than long, with 2 depressions separated by ridge. Lateral corner of merus covers distal end of exopod. Palp folded medially, last 2 articles concealed by merus; carpus, propodus, dactylus of decreasing size, upper distal corners of carpus, propodus slightly produced.

30


MCLAY & TAN

FIGURE 15. Garthambrus undulatus sp. nov. : holotype, male 44.4 x 29.0 mm (MNHN), New Caledonia, VOLSMAR, stn DW30, 22°17.0’S 171°17.7’E, 550 m, 5 Jun 1989. A, dorsal view; B, front view; C, side view

Inner margin of cheliped merus with 7 or 8 small blunt granules; outer margin with 7 or 8 sub-acute granules, distal 4 longer. Single, prominent sub-acute granule in middle of carpus. Outer margin of propodus armed with 8 or 9 granules, 5 longer than others. Inner border of propodus armed with 6 granules, last 3 longer, curving upwards towards base of dactyl. Upper border of dactyl with 4 sub-acute granules. Right cheliped (crusher) gaping, with only 2 distal teeth. Left cheliped (cutter) with only 4 weakly developed interlocking teeth. Male cheliped length 2x CW or 3x CL. Ambulatory legs decreasing in length posteriorly. Tubercle formula for ambulatory legs: P2: merus 6/2, carpus 1/0, propodus 0/0; P3: merus 6/2; no tubercles on carpus or propodus; P4 merus 5/(5 + 1), carpus 0/0, propodus 3/0; P5: merus 5(4 + 2), carpus 0/0, propodus 3/3. All tubercles stout, blunt. Dactyli shorter than propodi, ending in horny claw. REVISION OF THE CRAB GENUS GARTHAMBRUS


31

Male abdomen finely granular, medially convex; segments 3–5 fused, sutures only evident at margins. Medial curved hook on segment 6. Abdominal locking mechanism with large, smooth tubercles on sternite 5 fitting into deep sockets on posterior corners of segment 6. Telson triangular, distinctly wider than long, distally rounded, small medial pit present. Female unknown. G1 extends to middle of sternite 5, almost straight, narrowing distally, sperm aperture subterminal, directed medially, distal 10% covered by small, acute, proximally directed spines. G2 slightly longer than first, extending to middle of sternite 4, flagellum 46% of total length, twisted 90°. Transition from basal section of G2 to flagellum is not marked by notch. Ratio of length of G2/G1 = 1.15. Female unknown. Distribution. Known only from New Caledonia. Etymology. The species name refers to the smooth, undulating carapace surface of this species. Remarks. Garthambrus undulatus and G. cidaris look similar due to the broad epibranchial tooth. However, G. undulatus can be distinguished from G. cidaris because the anterior epibranchial margin ends in a long lateral tooth that is bifurcated at the tip. In G. cidaris, the lateral tooth is shorter and the tip is not bifurcated. In addition, the tubercles on the dorsal surface of the carapace are paxilliform and more numerous in G. cidaris, but blunt and less numerous in G. undulatus.

Hispidolambrus gen. nov. Diagnosis. Carapace sub-triangular, wider than long, CW/CL ratio around 1.6, surface without lacunae and bearing large acute spines; no smooth ridges or plates. Hepatic margin angular, forming a prominent shoulder and bearing a long spine. Anterior epibranchial margin partially covering walking legs, divided into two sections, both armed with evenly spaced spines. Posterior carapace margin armed with prominent spines. Chelipeds almost three times CL, fingers dentate, down-curved, upper margin of dactylus spinose. Margins of ambulatory pereopods densely spinose. Merus of third maxilliped subquadrate, wider than long, with prominent angled spinose ridge that continues across basis-ischium; mesial margin straight lateral margin tuberculate; carpus, propodus and dactylus exposed; exopod exposed, mesial margin distal one-third with tooth. Male thoracic sternum fused, tuberculate, depressed; transverse and longitudinal grooves present, fused medially, forming inverted V-shaped depression. Male telson triangular wider than long. G1 relatively stout, curved distally, tip rounded, armed with short stiff setae. G2 longer than G1; flagellum subequal to basal section. Type species: Asterolambrus mironovi Zarenkov, 1990, by monotypy. Etymology. This generic name derived from the Latin “hispidus”, an adjective meaning “beset with stiff hairs or bristles”, alluding to the accentuated spines covering the body and limbs. The name is an arbitrary combination with Lambrus, a common suffix for many parthenopid genera. Remarks. Although Hispidolambrus mironovi resembles some species of Garthambrus in its body shape, the structure of the anterior epibranchial margin and the many spinose features are not found in any of the species in that genus. In their synopsis of the genera of the Parthenopinae MacLeay, 1838, Tan & Ng (2007) include a new genus Spinolambrus Tan & Ng, 2007. This genus includes nine spinose species that are found in the Atlantic and Mediterranean Seas (seven species) and eastern Pacific (two species). Hispidolambrus mironovi also comes from the eastern Pacific, but is unlikely to be confused with either S. exilipes (Rathbun, 1894) or S. johngarthi (Hendrickx & Landa-Jaime, 1997) because the Spinolambrus species all have an ovoid-shaped body, which does not cover the meri of the ambulatory pereopods, and there is no shoulder on the hepatic margin. While Hispidolambrus might prove to be closely related to Garthambrus, any relationship with Spinolambrus seems more distant.

32


MCLAY & TAN

Hispidolambrus mironovi (Zarenkov, 1990) nov. comb. (Figs 16, 17) Asterolambrus mironovi Zarenkov, 1990: 233, fig. 11. Parthenope (Platylambrus) mironovi — Garth 1993: 792, fig. 6. – Parin et al. 1997: 163 (list). Parthenope mironovi — Parin et al. 1997: 217. Garthambrus mironovi — Ng 1996: 156, 158. – Ng & Tan 1999: 122 (key).

FIGURE 16. Gonopods. Hispidolambrus mironovi (Zarenkov, 1990) nov. comb: A, B, male 42.5 x 26.8 mm (LACM CR 19582671; ex. AHF 5821), Shoal Guyot, Eastern Pacific (after Garth 1992: fig. 6f) (scale bar = 1 mm); C, D, male CL = 30 mm, Kupol Seamount, RV Professor Shtockman, stn 2029, 9 May 1987 (no scale bar available) (after Zarenkov, 1990: fig. 11). A, C, right G1; B, D, right G2.

Type material. SYNTYPES: 1 ovig. female (CL 32.0 mm), Bolshaya Seamount, stn 1921; 1 male (CL 20.2 mm), 1 female (CL 19.4 mm), Bolshaya Seamount, stn 1924; 1 male (CL 17.2 mm), Kupol Seamount, stn 1992; 1 female (CL 26.5 mm), Ichthyologists Seamount, stn 1996; 1 male (CL 21.8 mm), Kupol Seamount, stn 2038; 1 male (CL 30.0 mm), Kupol Seamount, stn 2029. The precise localities were not given in the original description. Garth (1993) examined a male specimen from station 1992 and designated it as a paratype. He noted that this specimen is from the Ichythologists Seamount, but the locality of station 1992 should be from the Kupol Seamount (Zarenkov, 1990: 233). Garth (1993) also gave the carapace measurement of the male specimens (32.0 x 22.3 mm), but the carapace length is different from that given by Zarenkov (1990) which is CL=17.2 mm. The discrepancy could be due to whether the long spine-like teeth on the posterior margins in the carapace length were added to the measurements taken by Garth (1993). Material examined. Shoal Guyot: Scripps Institute of Oceanography Downward Expedition, Station HD–73, 25°44’S, 85°25’W, 228 m, rock dredge, 26 Jan 1958: 1 male 42.5 x 26.8 mm (damaged) (LACM CR 19582671; ex. AHF 5821). Diagnosis. Dorsal surface of carapace tuberculate, tubercles stellate, without deep lacunae; supra-orbital region spinose. Protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions with large spines, tubercle or spines not fusing together to form smooth ridges or plates. Frontal projection short, less than one quarter carapace length. Epibranchial marginal teeth sharp. Anterior epibranchial margin divided into two



33

sections: anterior section arcuate posterior section straight. Mesobranchial margin without a raised smooth triangular patch. Sub-orbital spine produced, spine tip extending beyond anterior outer corner of antennal article 2. Sub-branchial region densely tuberculate, tubercles paxilliform, stellate. Cheliped merus, carpus outer margins spinose. Upper margin of P5 merus, carpus, propodus spinose; posterior surface spinose.

FIGURE 17. Hispidolambrus mironovi (Zarenkov, 1990): male 42.5 x 26.8 mm (LACM CR 19582671; ex. AHF 5821),

Shoal Guyot, Eastern Pacific (after Garth 1992: fig. 6a) (scale bar = 10 mm).

Distribution. Known only from the type locality, Nazca and Sala y Gómez submarine ridges, Eastern Pacific. Specimens of this species had been collected from between 162 to 800 m (Zarenkov, 1990; Garth, 1992).

Remarks. The crushed and dried specimen from the Los Angeles County Museum that was examined was collected almost at the same place where the type material was taken. Hispidolambrus mironovi has distinctively spiny carapace and ambulatory legs. It also has a CW/CL ratio 1.5–1.6, similar to Garthambrus stellatus. Garthambrus stellatus can be distinguished from H. mironovi by not having spines on the carapace and chelipeds, while granules on the carapace are stellate. There is also no distinct notch on the anterior epibranchial margin on G. stellatus, which is present in H. mironovi and divides this margin into two sections. We have not been able to examine the gonopods of this species, but there are two illustrations of these in Zarenkov (1990, his Fig. 11) and Garth (1993, his Fig. 6f) and since there are some minor differences we reproduce both here as Fig. 16.

34


MCLAY & TAN

Hispidolambrus mironovi probably grow to a reasonably large size: Garth (1993) reported a male 42.5 x 26.8 mm from the Guyot Shoal, near San Félix I. (Chile) on the Juan Fernandez Ridge. Zarenkov (1990) recorded an ovigerous female CL = 32.0 mm (using the CW/CL ratio of other specimens, 1.5, that would estimate the CW as being around 48 mm) from the Bolshaya Seamount. Of all the species dealt with herein H. mironovi is found closest to continental South America. Its distribution ranges from Sala y Gomez to San Félix I., both island groups being part of Chile.

Zarenkolambrus gen. nov. Diagnosis. Carapace triangular to pentagonal, carapace wider than long; surface smooth or finely granular; regions not well defined. Hepatic margin approximately linear, without tubercles or teeth; hepatobranchial notch not well marked; anterior epibranchial margin armed with small irregular teeth. Epistome with shallow central depression, lateral depressions only faintly marked. Subhepatic region not concave, no hepatic fissure. Shallow V-shaped depression on third and fourth sternites. Basis-ischium of third maxillipeds with wellmarked central longitudinal ridge, medial blade-like margins meet when closed. Surface of merus concave, covered with tubercles of various sizes, lateral corner covers exopod. Palp folded medially, last 2 articles covered by edge of merus. Cheliped margins minutely dentate; manus outer margin with two low, broad teeth; teeth on fingers poorly developed; prominent single tubercle on upper margin of dactyl. Ambulatory legs decrease in length posteriorly, dactyli longer than propodi. Male telson wider than long. G1 stout, curved, not armed narrows quickly to straight distal portion, sperm aperture sub-terminal and medially directed. G2 slightly longer than G1, flagella as long as basal section, twisted. Type species: Zarenkolambrus minutus sp. nov. Included species: Heterocrypta epibranchialis Zarenkov, 1990 Etymology. The genus is named after N. A. Zarenkov, the prominent Russian carcinologist, in arbitrary combination with the parthenopid generic name, Lambrus, a common suffix for many parthenopid genera. Remarks. This genus resembles the smoother members of the genus Garthambrus but has the regions on the carapace somewhat less elevated. In all Garthambrus species, the epibranchial regions are typically strongly elevated and with varying degrees of tuberculation, rugosity or lacunation. In Zarenkolambrus, the epibranchial region is typically a narrow ridge and the outer margin of the cheliped manus has two low, but broad teeth, whereas in Garthambrus, there are typically more than two teeth on the same margin. Key to Zarenkolambrus Species 1. -

Rostrum long, not deflexed, tip with a varying number of short teeth on lateral margins. Lateral teeth long, carapace width much greater than carapace length ........................................................................................... Z. epibranchialis Rostrum short, deflexed, tip without teeth on lateral margins. Lateral teeth short, carapace width around 1.2 x carapace width .................................................................................................................................................... Z. minutus

Zarenkolambrus minutus sp. nov. (Figs 18A, B, 19) Type material. HOLOTYPE: male 6.2 x 5.1 mm (MNHN-B31883), French Polynesia, Austral Is (Raevavae), SMCB, stn D66, 23°50.54’S 147°42.73’W, 400 m, 3 Dec 1990.



35

FIGURE 18. Gonopods. Zarenkolambrus minutus sp. nov.: A, B, holotype male 6.2 x 5.1 mm (MNHN), French

Polynesia, Austral Is, Raevavae, SMCB, stn D66, 23°50.54′S 147°42.73′W, 400 m, 3 Dec.1990 (scale bar = 1mm). — Zarenkolambrus epibranchialis (Zarenkov, 1990): C, D, male CL 5.0 mm, eastern Pacific Ocean, near Sala y Gómez, Ignolnaya, RV Professor Stockman, stn 2007, 6–7 May 1987 (after Zarenkov 1990: fig. 10) (scale bar not available). A left G1, B, left G2; C, right G1; D, right G2.

PARATYPE: 1 male 4.1 x 3.5 mm (MNHN-B31884), French Polynesia, Austral Is (Raevavae), SMCB, stn D66, 23°50.54’S, 147°42.73’W, 400 m, 3 Dec 1990. Description. Carapace wider than long, sub-pentagonal, surface very finely granular. Rostral region broad, median rostral tooth scarcely projecting, deflexed; lateral rostral teeth absent. Frontal region slightly concave, supraorbital region not elevated, no mid-orbital pit. Convex ridge runs length of mesogastric, metagastric, cardiac regions. No projections on central ridge, weak anterior diagonal branchial ridge ends at posterior epibranchial corner. Weak ridge present on posterior branchial, 3 faint pits in branchiocardiac groove, but solitary tubercle is absent. Regions not clearly marked. Orbital margin finely denticulate, strongly concave to supraorbital suture. Suborbital margin concave to subacute tooth. Hepatic margin not projecting ended by distinct notch. Anterior epibranchial margin armed with 12 or 13 small, blunt teeth, becoming weaker posteriorly. Posterior epibranchial corner blunt, not projecting. Posterior epibranchial margin concave, 3 weak teeth near posterior margin. Blunt tooth present at each end of posterior margin which is convex, granular. Epistome with shallow central depression, lateral depressions only faintly marked. Subhepatic region not concave, no hepatic fissure. Finely granular ridge runs, without interruption, from corner of buccal frame to sub-branchial region. Pterygostomial region finely granular. Cheliped-blocking mechanism involves proximal spine on posterior margin of merus against prominent sub-branchial spine near base of cheliped. Shallow Vshaped depression on sternites 3, 4. Only sternite 6/7 complete. Antennular article 1 mobile, 6-sided; article 2 much longer than wide, inserted medially, folded away at an oblique angle; article 3 much longer than wide; articles 3, 4 normally folded in antennular fossa. Antennal article 1 mobile, wider than long, convex; article 2 trapezoidal, convex, fixed to epistome, suborbital margin; article 3, 4 mobile longer than wide; flagellum as long as articles 3, 4 combined. Basis-ischium of third maxillipeds with well-marked central longitudinal ridge, medial blade-like margins meet when closed. Surface of merus concave, covered with tubercles of various sizes, lateral corner covers exopod. Palp folded medially, last 2 articles covered by edge of merus.

36


MCLAY & TAN

Inner margin of cheliped merus with 7 tubercles, outer margin with tubercle near base (part of the cheliped-blocking mechanism), faint median tubercle. Carpus finely granular. Inner margin of propodus with 3 evenly spaced, low tubercles; outer flange-like margin, continuous from near carpus, curving towards base of dactylus, without tubercles; dactylus with proximal tubercle on upper margin. Right cheliped (crusher), with 2 or 3 faint teeth on each finger, left cheliped (cutter), with 3 or 4 small interlocking teeth.

FIGURE 19. Zarenkolambrus minutus sp. nov. : holotype male 6.2 x 5.1 mm (MNHN), French Polynesia, Austral Is (Rae

Vavae), SMCB, stn D66, 23°50.54’S, 147°42.73’W, 400 m, 3 Dec 1990.

Ambulatory legs decrease in length posteriorly. The arrangement of tubercles on legs as follows: P2: merus 4/0; P3: merus 7/0; P4: merus 6/(6 + 0); P5: merus 6/(7 + 6); all other articles of P2 to P5 are devoid of tubercles. Dactyli longer than propodi. Lateral parts of abdominal segment 3 raised, low central ridge with scattered tubercles on segments 4–6. Segments 3, 4 fused but sutures still evident. No median hooked tubercle on segment 6. Abdominal locking mechanism of tubercles on sternite 5, sockets on segment 6. Male telson slightly wider than long. G1 reaches anterior margin of sternite 5, narrows quickly to straight distal portion, sperm aperture sub-terminal, medially directed. G2 reaches middle portion of sternite 4, slightly longer than G1, tip straight, flagella as long as basal section, twisted. Female unknown. Distribution. Known from the type locality. Etymology. The species name is derived from the Latin minutus alluding to the small size of the new species. Remarks. Zarenkolambrus minutus resembles Z. epibranchialis but differs in the carapace width (CW) to carapace length (CL) ratio, which is 1.2 in Z. minutus but 1.4 in Z. epibranchialis. In addition, the rostrum is much shorter in Z. minutus than in Z. epibranchialis, and the posterior epibranchial corners are not as produced as those in Z. epibranchialis.



37

Zarenkolambrus epibranchialis (Zarenkov, 1990) comb. nov. (Figs 18C,D, 20) Heterocrypta epibranchialis Zarenkov, 1990: 232, fig. 10. – Parin et al. 1997: 163 (list).

Type material. SYNTYPES: 2 males CL 4.8 mm, CL 5.0 mm, Southeast Pacific Ocean. Near Sala y Gómez and Utes seamounts, stn 2003, 330–350 m, RV Professor Shtokman; 1 damaged specimen, Igolnaya Seamount, stn 2007, 290–310 m, RV Professor Shtokman: Data after Zarenkov (1990). None of these specimens were examined. Diagnosis. Carapace finely granular, not spinose, without deep lacunae; supra-orbital region without spines. Tubercles on protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions not fusing together to form smooth ridges or plates. Rostrum long, about one-quarter carapace length. Epibranchial margin teeth flat, edges irregular. Sub-orbital spine produced, tip extending beyond anterior outer corner of antennal article 2. Outer margins of cheliped merus and carpus not tuberculate, appearing entire. P5 upper margin of merus, carpus and propodus dentate. Distribution. Southeastern Pacific (290–350 m) and Nazca and Sala y Gómez submarine ridges, Eastern Pacific (Zarenkov, 1990). Remarks. The diagnostic features, originally given in Russian by Zarenkov (1990) and translated by A. Anker, are as follows: “whole body surface finely granular. Rostrum triangular, apex rounded, sides slightly concave. Posterior edge of orbits with small notch. Border of branchiostegal region with 6–8 irregular, flattened teeth. Lateral border of carapace continued by somewhat rounded process. Posterior epibranchial border of carapace separated from posterior border by some teeth. Dorsal surface of carapace inflated in the middle and bears some feebly marked epibranchial keels. Telson triangular, abdominal segment 6 with large/ tubercle in middle of anterior border. Shape of sixth segment trapezoidal. Eye stalk minutely tuberculate. Basal article of antenna with sub-terminal process. Deep depression of antennule not completely separated from orbit by rostral process. Third maxilliped ischium and merus granular, anterior borders depressed. Lateral anterior part of merus slightly expanded. Cheliped cutting edges not regular. Upper surface of dactylus with teeth and large process near articulation. Three flattened teeth on upper surface of propodus with large process near carpus. Dactylus also with process. Cheliped merus with one shallow process (tooth), with small process (tooth) in the middle, also four on the inner side. Meri of P2–P5, have 5–7 granules/teeth on anterior margin. Same kind of teeth also present on posterior margin of P4 and P5. P2 and P3 without teeth on posterior margin. Lower surface of carpus smooth but upper surface granular (P2–P5). Propodus of P2–P5 granular on both margins. Dactylus straight; surface smooth.” It is clear from the text and the illustration (Zarenkov, 1990: 233, fig. 10) that this species does not belongs in the genus Heterocrypta Stimpson, 1871, or similar genera like Cryptopodia H. Milne Edwards, 1834, or Furtipodia Tan & Ng, 2003. It does not resemble any of these genera because of the differences in carapace shape. The posterior lateral portion of the carapace of Z. epibranchialis is clearly not expanded to cover the ambulatory legs as in Cryptopodia. In addition, Z. epibranchialis has prominently produced lateral teeth, which are absent in Heterocrypta, Cryptopodia and Furtipodia. Although we did not examine any specimens of this species, illustrations of this species, although somewhat schematic, show that it has several unique features. Its most prominent feature is the long rostrum, which is about one quarter of the entire carapace length. We believe that the long rostrum is more apparent than real and is the result of the orientation used by Zarenkov (1990) for his illustration (Fig. 10). The other Zarenkolambrus species, Z. minutus has a much shorter rostrum. The gonopods shown in Fig. 6E & F are probably those of an immature male because the G2 flagellum is not twisted, so the exact adult gonopods are yet to be determined. Zarenkolambrus epibranchialis is only known from two small males (CL 4.8–5.0 mm) and one damaged specimen.

38


MCLAY & TAN

FIGURE 20. Zarenkolambrus epibranchialis (Zarenkov, 1990): lectotype, M CL 5.0 mm, (after Zarenkov 1990: fig. 10).

A, carapace; B, P1; C, P2; D, P3; E, P4; F, P5; G, abdomen; H, ventral view (no scale bar available).

Tutankhamen Rathbun, 1925 Tutankhamen Rathbun, 1925: 530. – Gore & Scotto 1979: 62. – Ng et al., 2008: 132.

Type and only species. Mesorhoea cristatipes A. Milne-Edwards, 1880, by original designation. Gender masculine. Diagnosis. Carapace sub-triangular, broader than long, CW/CL ratio = 1.25, regions inflated; dorsal surface smooth; epibranchial margin expanded, partially covering ambulatory legs; not produced beyond base of abdomen; no lateral ventral depression. Rostrum spatulate. Postorbital angle slightly obtuse. Gastro-orbital notch absent. Hepatic margin not continuous with epibranchial region. Hepatobranchial notch present, distinct, broad. Epibranchial margin slightly convex, posterior one-seventh angled, angle acute; teeth triangular, narrow, U-shaped gaps present between adjacent teeth; last epibranchial tooth anterior to posterior margin, fused with preceding tooth. Proto-, meso- and metagastric regions differentiated, without ridge. Hepatic region slightly inflated, lower than epibranchial and gastric regions. Epibranchial region without continuous diagonal ridge. Sub-orbital region without diagonal ridge, excavated laterally and mesially; suborbital margin gently curving. Epistome slightly depressed medially, anterior half with strong protruding lamelliform ridge, without protrusion below antennular article 1, lower margin broadly V-shaped. Pterygostomial region excavated, no distinct afferent channel. Pterygostomial ridge lamelliform, without dense setae covering afferent channel, not continuous with sub-epibranchial ridge. Distinct sub-hepatobranchial notch present. Sub-epibranchial region narrow, smooth. Posterior sub-branchial teeth absent. Antennal article 3 long, nearly reaching anterior lateral corner of antennular article 1; anterior margin of antennal article 4 above antennular article 1 anterior lateral corner, shorter than antennal article 3.



39

Third maxilliped merus sub-quadrate, upper margin entire, anterior lateral corner expanded, anterior mesial corner with slight diagonal hiatus, carpal junction with indistinct hiatus; carpus outer surface with short distal spine, exposed; propodus outer surface with short distal spine, exposed; dactylus exposed; exopod exposed, tip partially hidden by merus anterior lateral corner, tooth on mesial margin at distal one-third. Cheliped margins dentate to cristate, teeth relatively broad, broadly triangular; merus upper surface smooth; dactylus about 45º to manus central axis. Lamelliform projection on cheliped coxa. Male thoracic sternum smooth, strongly depressed, forming inverted U-shape; transverse and longitudinal grooves absent. Male telson triangular, longer than broad. G1 relatively stout, tip rounded, not armed with long spines or stiff setae. G2 longer than G1; flagellum as long as basal section, twisted. Remarks. The type species of this genus was originally placed in Mesorhoea Stimpson, 1871, but bears no similarities to other species in that genus. Rathbun (1925) noted that the afferent channels of M. cristatipes A. Milne Edwards, 1880, differed markedly from other Mesorhoea species being “shorter and deeper, bordered above by a laminar expansion of the hepatic and anterior branchial margins, below by a parallel lamina having an emargination near the beginning of the branchial regions; the canals terminate in a cul-desac behind the orbit and open on the epistome by a fissure between the external angle of the thin lamina which forms the anterior edge of the buccal cavity and a promontory formed by the infero-internal angle of the orbit. Epistome spacious and very concave, separated by a thin ridge and a considerable interval from the antennules.” It is not quite clear what Rathbun (1925) meant by “infero-internal angle” means and we presume that it refers to the inferior-internal angle. In addition she pointed out that the maxilliped merus does not have the antero-internal angle produced anteriorly unlike Mesorhoea sensu stricto. Rathbun (1925) created Tutankhamen to accommodate M. cristatipes. Tutankhamen cristatipes is, however, morphologically similar to some Garthambrus species, in particular G. pteromerus (see Fig. 22E–H). The similarities include a sub-triangular shaped carapace that is relatively smooth dorsally and the proximal half of the cheliped merus outer margin dentate, whereas the distal half of the cheliped merus outer margin is entire. The resemblance also extends to the similarly shaped G1 and G2. The G2, as in all Garthambrus species, is longer than the G1. However, Tutankhamen is not congeneric with Garthambrus. Tutankhamen can be differentiated from Garthambrus by having a greatly expanded pterygostomial ridge. This ridge is entire and protrudes out so much that it is visible dorsally. In Garthambrus, the pterygostomial ridge is never visible dorsally. In Tutankhamen, there is a strong lamelliform process in the middle of the epistome. This lamelliform process is absent or reduced in Garthambrus. On the first antennular article of Tutankhamen, there is a strong crista of about the same length as that of the first antennal article, which is also parallel to the central axis of the carapace. This crista is absent in Garthambrus. In addition, the ambulatory leg dactyli are glabrous in Tutankhamen, but pubescent in Garthambrus.

Tutankhamen cristatipes (A. Milne-Edwards, 1880) (Figs 21, 22 A–D) Mesorhoea cristatipes A. Milne-Edwards, 1880a: pl. 31A figs 6–6c; 1880b: 352; 1880c: 5; A. Milne-Edwards & Bouvier 1923: 359, pl. 10 fig. 3. Lambrus cristatipes — Rathbun 1898: 261. Tutankhamen cristatipes — Rathbun 1925: 530, pl. 277 figs 3–5. – Ng et al., 2008: 132.

Type material. HOLOTYPE: male 16.9 x 13.5 mm (MCZ 8943), Blake Expedition 1878–79, stn 269, Caribbean Sea, Windward Is, off St. Vincent, 13º07’36”N, 61º05’36”W, 227 m, A. Agassiz coll., 3 Mar 1879. Diagnosis. As for generic diagnosis. Distribution. Known only from the Caribbean Sea: Windward Is and Pourtales Plateau. Depth range 227–366 m (Rathbun, 1925).

40


MCLAY & TAN

Remarks. It is intriguing to note that the species closest in appearance to T. cristatipes is G. pteromerus from the Pacific. Both species have relatively smooth carapace surface, which are sub-triangular in shape, but G. pteromerus is relatively much wider CW/CL = 1.35–1.55 vs 1.25 for T. cristatipes. Both species have strong cristae on the upper and lower margins of the ambulatory legs and also have the proximal half of the cheliped merus outer margin dentate, but with the distal half being entire.

FIGURE 21. Gonopods: (A, B) Tutankhamen cristatipes (A. Milne-Edwards, 1880): holotype, male 16.9 x 13.5 mm

(MCZ 8943), Caribbean Sea, off St. Vincent. Scale bar = 1 mm. A, right G1; B, right G2.

This poses some interesting questions about the relationship between Tutankhamen and Garthambrus. Garthambrus pteromerus is actually atypical of most Garthambrus species, having a relatively smooth carapace surface albeit somewhat pitted. But, most importantly, it has a relatively smooth and entire pterygostomial ridge, which is similar to that of Tutankhamen. However, it is not as expanded as that of T. cristatipes and never visible dorsally in G. pteromerus. As such, G. pteromerus may be possibly a link between Garthambrus and Tutankhamen. However, the easternmost record of G. pteromerus is in the Philippines, a considerable distance from the Caribbean Sea. Alternatively G. lacunosus, which is superficially very similar to G. pteromerus, from Hawaii, is another possible link. This could possibly due to the paucity of sampling because there are very few deep-sea samples from around the Hawaiian Is. Furthermore, very few specimens of T. cristatipes have been reported. The relationship between Garthambrus and Tutankhamen thus, remains unclear, but future discoveries and molecular studies could result in changes such that Tutankhamen includes species that have an Eastern Pacific/Caribbean distribution.



41

FIGURE 22. Tutankhamen cristatipes (A. Milne-Edwards, 1880): A–D, holotype, male 16.9 x 13.5 mm (MCZ 8943),

Caribbean Sea, off St. Vincent. — Garthambrus pteromerus (Ortmann, 1893): E–H, male 19.2 x 13.4 (ZRC), Philippines, Visayas, Bohol, Panglao, Balicasag I. A, E, carapace, dorsal surface; B, F, epistome; C, G, sternum and abdomen; D, H, side profile.

42


MCLAY & TAN

Key to genera The following key may be used to identify the four parthenopid genera dealt with in this paper: 1. 2. 3.

-

Body sub-triangular, arrow-head shaped, hepatic and anterior epibranchial margin form an almost straight line ..... 2 Hepatic margin angular, forming a shoulder that interrupts hepatic-epibranchial margin which may be convex ..... 3 Epistome not strongly lamelliform ...................................................................................... Zarenkolambrus gen. nov. Epistome strongly lamelliform ....................................................................................... Tutankhamen Rathbun, 1925 Carapace surface very spinose, strong acute hepatic tooth on shoulder, anterior epibranchial margin divided into two sections, the anterior section distinctly arcuate the posterior section straight, posterior carapace margin armed with 5–6 strong spines................................................................................................................... Hispidolambrus gen. nov Anterior epibranchial margin not divided into two sections, posterior margin normally trilobed, lobes blunt.............. ................................................................................................................................................. Garthambrus Ng, 1996

In the key provided by Tan & Ng (2007) the species belonging to these genera key out to couplet 25 (p. 100) i.e. Tutankhamen/Garthambrus, so the above key can be inserted at that point in their key.

Discussion Garthambrus Ng, 1996, as envisaged by Ng (1996) enabled re-focussing of the genera Platylambrus Stimpson, 1871, and Parthenope Weber, 1791, by removal of some species and the creation of the new genus. In the present revision of Garthambrus we have altered the carapace surface character from “granulose, spinose or rugose” to “granulose, tuberculate, smooth or pitted”. This allows species with a smooth carapace to be included, but excludes those with a spinose carapace. In fact Ng (1996) had included species with a smooth carapace but not made this explicit in the generic diagnosis. The major effect of the change is to exclude the spinose species, Garthmabrus mironovi (Zarenkov, 1990), which was originally placed in this genus. Table 1 summarizes the characters of Garthambrus and Hispidolambrus gen. nov. as well as Tutankhamen because of its obvious links to Garthambrus. We also include Zarenokolambrus gen. nov. because it also has a similar shaped triangular body. The creation of this genus solves the problem of where to place Heterocrypta epibranchialis Zarenkov, 1990, and, as fortune favours us, we have a new species that can also be placed in Zarenkolambrus. The present work is a further refinement of the parthenopid revision initated by Ng (1996). This brings the total number of genera in the Parthenopinae to 34. A summary of the depth distribution and size range of the species of Garthambrus, Hispidolambrus, Zarenkolambrus and Tutankhamen is provided in Table 2. Garthambrus species have an Indo-West Pacific distribution, as far east as French Polynesia, but the apparent diversity in the west Pacific is to some extent as reflection of the distribution of sampling effort. Ng (1996) stated that Garthambrus is mainly a deep-sea genus. However, we have found that the shallowest depth where a Garthamabrus species has been found is 81 m (G. pteromerus). However, most specimens of Garthambrus have been collected between 250–600 m (greatest depth is 720 m for G. poupini). For most species, where both males and females are known, both sexes grow to a similar size. G. stellatus males grow to CW of almost 70 mm. By contrast, both species of Zarenkolambrus are small (~ 6 mm CW) and only males are known. It is very likely that these specimens are immature so further collections will be required to ascertain the adult size range. Similarly, only male Tutankhamen cristatipes are known, but at CW= 17 mm, these crabs are probably mature. For the other genus, Hispidolambrus, the specimens that have been collected reach sizes, approaching those of Garthambrus posidon and G. stellatus. Zarenkov (1990) reported an ovigerous H. mironovi female of 48 x 32 mm (est.). The geographic distribution of the species of Garthambrus, Hispidolambrus, Zarenkolambrus and Tutankhamen is summarized in Table 2. Looking at the occurrence of the species of Garthambrus across the Indian and Pacific Oceans we find only one species in the Indian Ocean, nine species in the West Pacific, three species from the Hawaiian Is and three from French Polynesia, with easternmost species being G. allisoni



43

which has been collected near Easter I. It seems reasonable to assume that the centre of origin of the genus was in the West Pacific where species diversity is greatest. Only one species, G. posidon, evolved towards the west in the Indian Ocean, while decreasing numbers of species colonized and evolved in seas to the east. The other three closely related genera only occur east of French Polynesia: Hispidolambrus and Zarenkolambrus are only known from the vicinity of Easter I. and San Felix I., while Tutankhamen is only known from the Caribbean. A possible scenario for evolution within these genera could be that Tutankhamen, Hispidolambrus and Zarenkolambrus shared a common ancestor with Garthambrus, having evolved in the Eastern Pacific, with only Tutankhamen colonizing the Caribbean Sea before closure of the Isthmus of Panama.

Acknowledgements We would like to thank Peter Ng (National University of Singapore) and Alain Crosnier (Institut de Recherche pour le Développement, Paris) for initiating and providing support for this project. Colleagues in overseas institution have generously allowed us to examine specimens under their care. We would like to thank Lucius G. Eldredge (BPBM); Joel Martin and George Davis (LACM); Ardis Johnston, (MCZ); Danièle Guinot and Règis Cleva (MNHN); Paul Clark (NHM); Jung-Fu Huang (NKIMT); Masatsune Takeda (NSMT); Tin-Yam Chan (NTOU); Shane Ahyong (NIWA); Peter Davie (QM); the late Lipke B. Holthuis and Charles Fransen (RMNH); Michael Türkay, Michael Apel and Andreas Allspach (SMF); Rafael Lemaitre and Karen Reed (USNM); Dirk Platvoet (ZMA); and Danny Eibye-Jacobson (ZMUC). Arthur Anker helped with the translation of a Russian text. This work was partly supported by the National University of Singapore Academic Research Fund grant R-154-000-044-112 and R-154-000-334-112, and by a grant from the University of Canterbury.

References Adams, A. & White, A. (1849) Crustacea, In: A. Adams (ed.), The Zoology of the Voyage of the H.M.S. Samarang; Under the Command of Captain Sir Edward Belcher, C.B., F.R.A.S., F.G.S. During the Years 1843-1846. Reeve, Benham & Reeve, London, pp. 33–66, pls 7–13. Ahyong, S.T. (2008) Deepwater crabs from seamounts and chemosynthetic habitats off eastern New Zealand (Crustacea: Decapoda: Brachyura). Zootaxa, 1708, 1–72. Balss, H. (1922) Ostasiatische Decapoden. III. Die Dromiaceen, Oxystomen und Parthenopiden. Archiv für Naturgeschichte 88, 104–140. Brito Capello, F. De (1871) Descripção de algumas especies novas de crustaceos. Jornal de Sciencias Mathematicas Physicas e Naturaes, 3 (12), 262–265, pl. 3. Clark, M. & O’Shea, S. (2001) Hydrothermal vent and seamount fauna from the southern Kermadec Ridge, New Zealand. Inter Ridge News, 10(2), 14–17. Crosnier, A. & Clark, P.F. (1998) Publication dates of the Recherches Zoologiques pour Servir à l’Histoire de la Faune de l’Amérique Centrale et du Mexique. Archives of Natural History, 25 (1), 87–101. Davie, P. J. F. (2002) Crustacea: Malacostraca: Eucarida (Part 2): Decapoda — Anomura, Brachyura, in A. Wells & W. W. K. Houston (eds), Zoological Catalogue of Australia. Vol. 19.3B. CSIRO Publishing, Melbourne, xiv + 641 p. Dong, Y.-M., Chen, Y.-S., Wang, F.-Z., Wang B.-Y. & Li, Z.-C. (1988) Report on the Crustaceans of the deep East China Sea: 1–132, 5 pls. Hangzhou University Publications, Hangzhou. (in Chinese). Edmondson, C.H. (1951) Some central Pacific crustaceans. Occasional Papers of the Bernice P. Bishop Museum, 2, 183–243. Flipse, H.J. (1930) Oxyrhyncha: Parthenopidae. Die Decapoda Brachyura der Siboga-Expedition. VI. Siboga Expeditite Monograph, 39c2 (112), 1–96. Garth, J.S. (1958) Brachyura of the Pacific Coast of America Oxyrhyncha. Allan Hancock Pacific Expeditions 21, part 1: i–xii, 1–499; part 2: 677–854, pls. A–Z, Z1–Z4, 1–55. Garth, J.S. (1993) Some deep-water Parthenopidae (Crustacea, Brachyura) from French Polynesia and nearby eastern Pacific Ridges and Seamounts. Bulletin du Muséum National d’Histoire Naturelle, sér. 4, 14, sect. A (3–4) [1992], 781–795. Garth, J.S. & Davie, P.J.F. (1995) A new species of Parthenope (Crustacea: Decapoda: Brachyura) from deep-water off northern Queensland. Memoirs of the Queensland Museum, 38 (1), 223–227. Gore, R.H. (1977) Studies on decapod Crustacea from the Indian River region of Florida. VI. The identity of Parthenope

44


MCLAY & TAN

(Platylambrus) serrata (H. Milne Edwards, 1834) and Parthenope (Platylambrus) granulata (Kingsley, 1879). Proceedings of the Biological Society of Washington 90(3), 505–531. Gore, R.H. & Scotto, L.E. (1979) Crabs of the family Parthenopidae (Crustacea Brachyura: Oxyrhyncha) with notes on specimens from the Indian River region of Florida. Memoirs of the Hourglass Cruises 3(6), 1–98. Guinot, D. & Bouchard, J.-M. (1998) Evolution of the abdominal holding systems of brachyuran crabs (Crustacea, Decapoda, Brachyura). Zoosystema 20(4), 613–694. Haan, W. de (1837) Crustacea. In: P. F. von Siebold, Fauna Japonica sive Descriptio Animalium, quae in Itinere per Japoniam, Jussu et Auspiciis Superiorum, qui Summum in India Batava Imperium Tenent, Suscepto, Annis 1823-1830 Collegit, Notis, Observationibus et Adumbrationibus Illistravit. Fascicle 3, 65–72, pls. 16, 18–24, E, F. LudduniBatavorum, Leiden. Hendrickx, M.E. & Landa-Jaime V. (1997) A new species of Parthenope Weber (Crustacea: Brachyura: Parthenopidae) from the Pacific Coast of Mexico. Bulletin de l’Institut Royal des Sciences Naturelles de Belgique 67, 95–100. Herbst, J.F.W. (1790) Versuch einer Naturgeschichte der Krabben und Krebse, nebst einer systematischen Beschreibung ihrer verschiedenen Arten 1(8), 239–274, pls 18–21. Kingsley, J.S. (1879) Notes on North American Decapoda. Proceedings of the Boston Society of Natural History 20, 145–160. Lanchester, W.F. (1900) On a collection of crustaceans made at Singapore and Malacca. Part I. Crustacea Brachyura. Proceedings of the Zoological Society of London 50, 719–770, pls 44–47. Leach, W.E. (1815) A tabular view of the external characters of four classes of animals, which Linné arranged under Insecta; with the distribution of the genera composing three of these classes into orders, &c. and description of several new genera and species. Transactions of the Linnaean Society of London 11, 306–400. Manning, R.B. & Holthuis, L. (1981) West African brachyuran crabs (Crustacea: Decapoda). Smithsonian Contributions to Zoology, 306, 1–379. Macleay, W.S. (1838) On the Brachyurous Decapod Crustacea. Brought from the Cape by Dr. Smith, in Illustrations of the Annulosa of South Africa; being a portion of the objects of natural history chiefly collected during an expedition into the interior of South Africa, under the direction of Dr. Andrew Smith, in the years 1834, 1835, and 1836; fitted out by “The Cape of Good Hope Association for Exploring Central Africa.” Invertebrate chapter in Illustrations of the Zoology of South Africa; consisting chiefly of figures and descriptions of the objects of natural history collected during an expedition into the interior of South Africa, in the years 1834, 1835, and 1836; fitted out by “The Cape of Good Hope Association for Exploring Central Africa.” by Andrew Smith, M.D., Deputy Inspector General of Army Hospitals; Director of the Expedition. Published under the Authority of the Lords Commissioners of Her Majesty's Treasury. Smith, Elder and Co. 65, Cornhill, London, 1849, 53–71, pls 2, 3. Martin, J.W. & Haney, T.A. (2005) Decapod crustaceans from hydrothermal vents and cold seeps: a review through 2005. Zoological Journal of the Linnean Society, 145, 445–522. Melo, G.A.S. de (1996) Manual de identificação dos Brachyura (caranguejos e siris) do litoral Brasileiro. Editora Plêiade/ FAPESP, São Paulo, 604 p. Miers, E.J. (1879a) On a collection of Crustacean made by Capt. H. C. St. John, R. N., in the Corean and Japanese Seas. Part I. Podophthalmia. With and appendix by Capt. H. C. St. John. Proceedings of the Scientific Meetings of the Zoological Society of London 1879, 18–61, pl. 13. Miers, E.J. (1879b) On the classification of the Maioid Crustacea or Oxyrhyncha, with a synopsis of the families, subfamilies, and genera. Journal of the Linnean Society, Zoology, London 14, 634–673, pls 12, 13. Milne-Edwards, A. (1878) Études sur les Xiphosures et les Crustacés podophthalmaires. In: Mission scientifique au Mexique et dans l’Amerique centrale. Recherches Zoologique pour servir à l’histoire de la fauna de l’Amérique centrale et du Mexique. Cinquième partie. Livraison 4, 121–184, pls 21–27, 29, 30. [See Crosnier & Clark (1998) for publication dates] Milne-Edwards, A. (1880a) Études sur les Xiphosures et les Crustacés podophthalmaires. In: Mission scientifique au Mexique et dans l’Amerique centrale. Recherches zoologique. Cinquième partie. Livraison 7, 265–312, pls 31A, 44, 49–54. Milne-Edwards, A. (1880b) Études sur les Xiphosures et les Crustacés podophthalmaires. In: Mission scientifique au Mexique et dans l’Amerique centrale. Recherches zoologique. Cinquième partie. Livraison 8, 313–368 + 8 pp. (unpaginated), pls 55–61. Milne-Edwards, A. (1880c) Reports on the Results of dredging under the supervision of Alexander Agassiz, in the Gulf of Mexico, and in the Caribbean Sea, 1877, ’78, ’79, by the U. S. Coast Survey Steamer “Blake,” Lieut.-Commander C. D. Sigsbee, U. S. N., and Commander J. R. Bartlett, U. S. N., Commanding. VIII. Études préliminaires sur les Crustacés, 1ere Partie. Bulletin of the Museum of Comparative Zoology at Harvard 8(1), 1–68, pls 1, 2. Milne-Edwards, A. & Bouvier, E.-L. (1923) XLVII. Les porcellanides et des brachyures. In: Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877-78), in the Caribbean Sea (1878-79), and along the Atlantic coast of the United States (1880) by the U. S. Coast Survey Steamer "Blake". Memoires of the Museum of Comparative Zoology 47(4), 283–395, pls 1–12. Milne Edwards, H. (1834) Histoire naturelle des Crustacés, comprenant l'anatomie, la physiologie et la classification des ces animaux, 1, i–xxxv + 1–468. Paris. Miyake, S. (1961) Decapoda Crustacea. In: Fauna and flora of the sea around the Amakusa Marine Biological Laboratory 2 (i–iv), 1–30. Monod, T. (1956) Hippidea et Brachyura ouest-africains. Memoires de l’Institut Français d’Afrique Noire, 45, 1–674.



45

Ng, P.K.L. (1996) Garthambrus, a new genus of deep water parthenopid crabs (Crustacea: Decapoda: Brachyura) from the Indo-Pacific, with description of a new species from the Seychelles. Zoologische Mededelingen, 70(10), 155–168. Ng, P.K.L. & Tan, S.H. (1999) The Hawaiian parthenopid crabs of the genera Garthambrus Ng, 1996, and Dairoides Stebbing, 1920 (Crustacea: Decapoda: Brachyura). Proceedings of the Biological Society of Washington, 112(1), 120–132. Ortmann, A. (1893) Die Decapoden-Krebse des Strassburger Museums, mit besonderer Berücksichtigung der von Herrn Dr. Döderlein bei Japan und bei den Liu-Kiu-Inseln gesammelten und zur Zeit im Strassburger Museum aufbewahrten Formen. VII. Theil. Abtheilung: Brachyura (Brachyura genuina Boas) II. Unterabtheilung: Cancroidea, 2. Section: Cancrinea, 1. Gruppe: Cyclometopa. Zoologische Jahrbüchner, 7, 411–495, pl. 17. Parin N.V., Mironov A.N. & Nesis K.N. (1997) Biology of the Nazca and Sala y Gómez submarine ridges, an outpost of the Indo-West Pacific Fauna in the Eastern Pacific Ocean: composition and distribution of the fauna, its communities and history In: Gebruk, A.V., Southward, E. C. & Tyler, P. A. (eds.), The Biogeography of the Oceans Advances in Marine Biology, 32, 145–242. Poupin, J. (1996) Atlas des Crustacés Marins profonds de Polynésie Française. Récoltes du navire MARARA (1986/1996). Service Mixte de Surveillance Radiologique et Biologique, Montlhéry, Cedex, France, pp. 1–59, pls 1–20. Rathbun, M.J. (1893) Scientific results of explorations by the U.S. Fish Commission steamer Albatross. XXIV. Descriptions of new genera and species of crabs from the west coast of North America and the Sandwich Islands. Proceedings of the United States Museum, 16, 223–260. Rathbun, M.J. (1898) The Brachyura of the biological expedition to the Florida Keys and the Bahamas in 1893. Bulletin from the Laboratories of Natural History of the State University of Iowa 4(3), 250–294, pls 1–9. Rathbun, M.J. (1906) The Brachyura and Macrura of the Hawaiian Islands. Bulletin of the United States Fisheries Commission, 23(1903), 827–830. Rathbun, M.J. (1925) The spider crabs of America. United States National Museum Bulletin, 129, i–xx, 1–613, pls 1–283. Rathbun, M.J. (1937) The oxystomatous and allied crabs of America. Bulletin of the United States National Museum, 166, 1–278. Righi, G. (1965) Uma nova espécie de Parthenopidae (Crustacea, Brachyura). Papéis Avulsos do Departamento de Zoologia. Secretaria da Agricultura, São Paulo, Brasil, 18(7), 57–60. Roux, P. (1828–1830) Crustacés de la Méditerranée et de son littoral, decrits et lithographiés. Paris and Marseille, iv + 176 p, pls 1–45. (See Manning & Holthuis 1981: 374 for details on publication dates) Sakai, T. (1934) Brachyura from the coast of Kyusyu, Japan. Science Reports of the Tokyo Bunrika Daigaku, section B, 1(25), 281–330, pls 17, 18. Sakai, T. (1935) New or rare species of Brachyura, collected by the “Misago” during the zoological survey around the IzuPeninsula. Science Reports of the Tokyo Bunrika Daigaku, section B, 2, 32, 63–88, pls 6–8. Sakai, T. (1936) Crabs of Japan. Sixty-six plates in life colours with descriptions. Sanseido, Tokyo, x + 239 p + 27 p [bibliography and index], pls 1–66. (In Japanese) Sakai, T. (1938) Studies on the Crabs of Japan. III. Brachygnathus, Oxyrhyncha. Yokendo, Tokyo, 193–364, pls 20–41. Sakai, T. 1965 The Crabs of Sagami Bay collected by His Majesty the Emperor of Japan. Maruzen, Tokyo, xvi + 206 p [English text], 92 p [Japanese text], 32 p [bibliography & indices], pls 1–100, 1 map. Saussure, H. De (1858) Mémoire sur divers crustacés nouveaux du Mexique et des Antilles. Memoires Societe Physique et d'Histoire Naturelle de Genève 14(2), 417–496, 6 pls. Serène, R. (1968) The Brachyura of the Indo-West Pacific Region. In: Prodromus for a Check List of the Non-Planctonic Marine Fauna of South East Asia, UNESCO, Singapore National Academy of Sciences, Special Publication 1, Fauna III Cc3, 33–112. Stimpson, W. (1871) Preliminary report on the Crustacea dredged in the Gulf Stream in the Straits of Florida, by L. P. de Pourtales, Assist. U. S. Coast Survey, Part I: Brachyura. Bulletin of the Museum of Comparative Zoology at Harvard College 2(2), 109–160. Takeda, M. & Miyake, S. (1969) Crabs from the East China Sea. III. Brachygnatha Oxyrhyncha. Journal of the Faculty of Agriculture, Kyushu University 15(4), 469–521, pls 17–18. Tan, S.H. (2004) A systematic revision of the Parthenopidae (Crustacea: Decapoda: Brachyura). Unpublished Ph.D. Thesis, National University of Singapore, 729 pp. Tan, S.H., Huang, J.-F. & Ng, P. K. L. (1999) Crabs of the family Parthenopidae of Taiwan (Crustacea: Decapoda). Zoological Sciences, 38(2), 196–206. Tan, S.H. & Ng, P.K.L. (2007) Descriptions of new genera of the sub-family Parthenopinae (Crustacea: Decapoda: Brachyura: Parthenopidae). Raffles Bulletin of Zoology Supplement, 16: 95–119. Weber, F. (1795) Nomenclator entomologicus secundum Entomologiam Systematicam ill. Fabricii adjectis speciebus recens detectis et varietatibus. Chilonii and Hamburgi, viii + 171 pp. Williams, A.B. (1965) Marine decapod crustaceans of the Carolinas. Fishery Bulletin, 65(1), 1–298. Yokoya, Y. (1933) On the distribution of decapod crustaceans inhabiting the continental shelf around Japan, chiefly based upon the materials collected by S. S. Soyo-Maru, during the year 1923–1930. Journal of the College of Agriculture Tokyo Imperial University, 12(1), 1–226. Zarenkov, N.A. (1990) Decapodae (Stenopodidea, Brachyura, Anomura) of the Nazca and Sala-y-Gomes Ridges. Transactions of the P. P. Shirshov Institute of Oceanology, Akademii Nauk, SSSR 124, 218–244. (In Russian)

46


MCLAY & TAN



47

48


MCLAY & TAN



49

50


MCLAY & TAN