Echinoderms through Time

PROCEEDINGS OFTHE EIGHTH INTERNATIONAL ECHINODERM CONFERENCE DIJON / FRANCE / 6-10 SEPTEMBER 1993

Echinoderms through Time Ediled by

\

Bruno David Universite de Bourgogne, Dijon. France

Alain Guille & Jean-Pierre Feral Observatoire Oceanologique. Bcmyuls/Mer, France

Michel Roux Universite de Reims. France

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Lawrmce,JohnM.(ed.) 9061912288 &hjpoderms: Procemiop olthe ioteroatioalll con&aeDDE9 'IlImJThe ~marionaJ ecJJinotUrms cOIIfermce. Tampa Bay. 14-17 Septe~rl98J 1982, 2S em. 552 pp.• H1l.320/SISO.00/£119 119 p&pm & abslracIs on behaviour. ecology. reproduction. development, morphology. paleontology. physiology. evolution. Syslemabcs & zoogeography. 53 photos. Jangoux. MidIeI.(ed.) 9061910773 &hloodrrms: Present and past - Procudings ofthe ~an col/cquium on echiruJderms. Brussels. 3-8 Sept. 1979 1980. 2S em, 480pp.. Hf1320/S1SO.oo/£119 SO selcetl!d pepen & abstracts on: Paleontology; Sk.e1elal SbUClW'eS; SysfmJll[ics & zoogeography; Ecology; Mocphology; FIIIICtiona1 morphology; General physiology; Reproduction; Embryology; Lar­ val biology. 133 phoIos. •...WeII written and carefully docwneoted;. valuable source ofinfor­ mation. Scima (212). Jangoux.M. &J.M Lawrmce(eds.) ISSN 0168-6 100 EdliDodam studies 1983-. 23cm,c.200pp.. Hfl.l45/SSO.oo/£S3 A biennial publicalion lXlIIIlIining comprehensi ve surveys of selcetl!d topics. Covers all aspectS of echinodenn biology. Volume 1.7 pIeoary 1ecIures read at Inl1. Conf. Echiooderms (Tampa,Sepc. 1981). 1983, 204pp.• 3 phoco5. 9061912903. \blume 2 Evolutiooary ecology & biogeography of recent Sla1k.ed ainoids; Larva1 ecology from the egg; EcoIogicaJ role of echioodenns in kelp foresu; Effects of salinily. 1987. 320 pp., 5 black/whirephocos.1 coIorpl.alc, 9061916461. Volume 3.ln1luenceof echinoderms inconl--rconununities; Echioodcrm~: Calciliarioo inechinodenns; Asteroidea: FW'lCtiooaI morphology. classification & phylogeny; Index ofnames of recent AsIeroidea; Biographical nocices. 1989, 396pp.,10pholos.9061917S65. Volume 4. How 10 study evolution in echinoderms: Complere physi­ ology of echinodenn muscle; Pharmacological effects of c0m­ pounds from echinoderms; An index of names ofrecent asteroidea ­ Pan 2: VaivaIida. 1993. 376pp, focos, 9054101172. •.. .for!hose in love with the beauties of the sea it is a n:aI treasure. R~ der ge.ranuen HydrobioL 75(5). ...aII science Iitmlries should consider adding illo lheir sh.elves. Quaff. Rev.Biol. 66( I ).

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Yaoagisawa. T.,I Yaswnasu, C. Oguro, N. Suzuki & T. Mocolcawa (ech.) 9054100109 BioIotlY oIEd1ioodermaaa - Proceedings of/he 7th inlemDlionai conference. AJami. Japan. 9-14 September 1m 1991. 2Scm. 604pp., Hfl.230/S13O.oo/£8S Complere papers and abstracts of all the presentations and posta'S of the conference. Topics: Ecology: Evolution; Reproduction; Mor­ phology; Molecular biology: Deveklpmenlal biology; Physiology; Behavior; 'Palaeon101ogy. 130 papers.

Burte. RD., P.V. M1a1denov. P. Lambcn & RL. PalSley(eds.) Echinoderm bioIoID'- Proceedings ofthe sixlh in/emDlionai COlI­ femra. Wetol"ia, 23-28Aug~ 1987 9061917557 1988, 25 em, 832 pp., Hfl.320/S1SO.ool£119 Ecology; Evolution & sy5lemalics; Reproduction; Morphology; Molecular biology; Development; Palae:ontology: Physiology; Cor­ owes & migrates • AIr. they ecIlinodetms or chordates; Holochwian biology; Hererclrony: R.egenaation; Behavior. •...undoubtedly 10 be recommended 10 all pcopIe iola'eSled in marine biology and invertebrare zoology. Hydrobiol BulL 24(2). Kcegan.B.F,&D.B.S.O'Conoor(ech.) 9061915961 Echioodermaaa - Proceedings ofrhe 5th inJemarionai echinoderm cOIIfel'f!nu, Galway, 24-29 Sep/ember 1984 1985.25 em, 679 pp.. Hfl.345 IS 195.001£128 76 papm & 67 abstnlClS. General: Crinoidea, Echinoidea; Holo­ lhurioidea; Asreroidea; Ophiuroidea. 134 photos.

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Echinoderms through Time. David. Guille. Feral & Raux (eds) © 1994 Balkema. RoNerdam. tSBN 90 54105143

Biogeography and area types of the southern ocean ophiuroids (Echinodermata,ophiuroidea) Igor S.SmimoY Laboratory of Marine Research, ZoologicallnstitUle, Russian Academy ofSciences, St. Petersburg. Russia

ABSTRACT: The ophiurid fauna of Antarctic shelves and Subantarctic islands is characterized by

a wide diversity of species. As a result of working over the Zoological Institute collections

and with the data from the literature included, the list has been enlarged to conSIst of 93

species, 34 genera and 9 families. When analysing the distribution of Antarctic and

subantarctic ophiuroids by comparing theIr species' areas, 19 main types of area have been

establighed. The waters of Antarctic and Subantarctic can be referred to as a single AntarctIC

Region with a high degree of endemism. The Antarct1c Region can then be divided into two

Subregions: Kerguelen and Glacial. The South Georgian region can be ranked as a separate South

Georgian Province within the Glacial Subregion. This will highlight the isolation of thlS

region from the Antarctic, the latter then be1ng referred to as Continental Province. cons1d­

ering 1ts rich fauna and some difference between the faunas of Antarctic peninsula and the

rest of the continent shelf this Province can be divided into two districts: South Polar and

«South Antill».

spaced deep-water shelf faunas of the Notal

Zone: the of Patagonian Shelf, Kerguelen,

Crozet, Heard, Prince Edward, Macquarie Is­

lands, Lena and Ob banks.

The mighty circumpolar current, severe cold

periods and glaciations have led to the forma­

tion of complicated biogeographical complexes

in notal and cold waters of the Southern Hemi­

sphere (Powell,1951; Fell,1953a,1962;

Knox, 1960) .

Today, there exist a great number of schemes

of biogeographical subdivision; it is possible

to sum them up as three main types:

1. The Antarctic district (usually ranked as

a Region) includes the Antarctlc shelf and islands of the Scotia Arc, including South Georgia (Ekman, 1935; Nybelin, 1947, 1951; Ekman, 1953; Knox, 1960; Kussakin, 1965, 1967, 1971; Kussakin, Andreev, 1980). 2. Together with the above mentioned re­ gions, Kerguelen, Crozet, Heard, Prince Edward and Macquar1e islands are also included into the Antarctic Region (Regan,1914; Norman, 1938; Andriashev, Tokarev,1958; Ushakov, 1962; Naurnov, Stepanjants,1962; Andriashev,1964; Averintsev,1972; Pushkin, 1977; Stepanjants,1979; Smirnov,1990). 3. The Antarctic region (zone) is considered as body of water embracing the continental shelf and the neighbouring islands includlng the South Orkney Islands. This conclusion was made by Koehler (1912) during his study of P~tarctic echinoderms distribution, and by Scotsberg (1964) on the basis of floristlc analysis.

The geological history of the Antarctic and adjacent regions, together with the long pe­ riod of formation of shallow water cold-tem­ perate faunas (25 to 30 million years - see Adie, 1963, 1970; Moyano, Hogo, 1978; George, 1979; Schultz,1979; Grosswald,1983,1984; etc.) and dissociation of Antarctic and Subantarctic island shelves has resulted in isolation of faunal groups of temperate and cold waters in the Southern Hemisphere. This isolat1on is characterized by a high degree of endemism at species and generic levels in various marine benthic groups (Ekman,1953; Andrlashev, 1964; Koltun,1969, etc.). Futher, the West Wind Drift (Antarctic Circumpolar current) is a powerful influence in drawing together the detached, mainly tem­ perate, faunas in the Southern Hemisphere. The current is thought to have originated in the Late Oligocene (l.e. 25 million years ago). A number of students consider its formation to be complete by the Middle Miocene (10-15 mil­ lion years ago -see (Kennett,1973,1974,1977; Grosswald,1983) . Transport of benthic organisms on floating macrophytes 1S well known for notal waters of the Southern Ocean (Andrlashev, 1964,1975; Averintsev,1972; Smirnov,1990, etc.). The West Wind Drift creates a considerable hydrological barrier, preventing the warm­ adopted forms of SUbtropical regions from penetrating into Antarctic waters. At the same time, it is a significant unit1ng factor for the widely

477

Echinoderms through Time, David, Guille, Feral & Roux (eds) © 1994 Balkema. Rotterdam, ISBN 90 5410514 3

Biogeography and area types of the southern ocean ophiuroids (Echinodennata, ophiuroidea) Igor S.Smimov Laborarory of Marine Research. Zoological InstiTuTe, Russian Academy ofSciences, ST. PeTersburg, Russia

ABSTRACT: The ophiurid fauna of Antarctic shelves and Subantarctic islands is characterized by

a wide diversity of species. As a result of working over the Zoological Institute collections

and with the data from the literature included, the list has been enlarged to consist of 93

species, 34 genera and 9 farrulles. When analysing the distribution of Antarctlc and

Subantarctic ophiuroids by comparing their specles' areas, 19 main types of area have been

established. The waters of Antarctic and Subantarctic can be referred to as a single Antarctic

Region with a high degree of endemism. The Antarctic Region can then be d~vided into two

Subregions: Kerguelen and Glacial. The South Georgian reg~on can be ranked as a separate South

Georg~an Province within the Glacial Subregion. This will highlight the ~solation of this

region from the Antarctic, the latter then being referred to as Continental Province. Cons~d~

ering its rich fauna and some difference between the faunas of Antarctic peninsula and the

rest of the cont~nent shelf this Province can be divided ~nto two districts: South Polar and

«South Antill».

spaced deep-water shelf faunas of the Notal

Zone : the of Patagonian Shelf, Kerguelen,

Crozet, Heard, Prince Edward, Macquarie Is­

lands, Lena and Ob banks.

The mighty circumpolar current, severe cold

periods and glaciations have led to the forma­

tion of complicated biogeographical complexes

in notal and cold waters of the Southern Hem~­

sphere IPowell,1951; Fell,1953a,1962;

Knox, 1960) .

Today, there exist a great number of schemes

of biogeographical subd~vision; it is possible

to sum them up as three main types:

1. The Antarctic district (usually ranked as

a Reg~on) includes the Antarctic shelf and islands of the Scot~a Arc, including South Georgia (Ekman, 1935; Nybelin, 1947, 1951; Ekman, 1953; Knox, 1960; Kussakin, 1965, 1967, 1971; Kussakin,Andreev, 1980). 2. Together with the above mentioned re­ gions, Kerguelen, Crozet, Heard, Prince Edward and Macquarie islands are also included into the Antarct1c Region (Regan,1914; Norman, 1938; Andriashev, Tokarev,1958; Ushakov.1962; Naurnov, Stepanjants,1962; Andriashev.1964; Averintsev,1972; Pushkin,1977; Stepanjants,1979; Smirnov,1990). 3. The Antarctic region (zone) is considered as body of water embracing the continental shelf and the neighbouring islands including the South Orkney Islands. This conclusion was made by Koehler (19121 during his study of Antarctic echinoderms distribution, and by Scotsberg (1964) on the basis of floristic analysis.

The geological history of the Antarctic and adjacent regions, together with the long pe­ riod of formation of shallow water cold-tem­ perate faunas (25 to 30 million years - see Adie,1963,1970; Moyano, Hogo, 1978; George, 1979; Schultz,1979; Grosswald,1983,1984; etc.) and dissociation of Antarctic and Subantarctic island shelves has resulted in isolation of faunal groups of temperate and cold waters in the Southern Hemisphere. Th~s isolation is characterized by a high degree of endemism at spec~es and generic levels in various marine benthic groups (Ekman,1953; Andr1ashev,1964; Koltun,1969, etc.). Futher, the We5t Wind Drift (Antarctic Circumpolar current) is a powerful influence in drawing together the detached, mainly tem­ perate, faunas in the Southern Hemisphere. The current is thought to have or~g~nated in the La te 01 igocene (i. e. 25 m11 11 on yea rs ago). A number of students consider its formation to be complete by the Middle Miocene (10-15 mil­ lion years ago -see (Kennett,1973,1974,1977; Grosswald,1983) . Transport of benthic organisms on floating macrophytes is well known for notal waters of the Southern Ocean (Andriashev,1964,1975; Averintsev,1972; smirnov,1990, etc.). The West Wind Drift creates a considerable hydrological barrier, preventing the warm­ adopted forms of subtropical regions from penetrating into Antarctic waters. At the same time, it is a significant un~t~ng factor for the widely

477

Orkney, South Shetland, Balleny, Bouvet, Kerguelen, Crozet, Macquarie, Prince Edward, Scott, Heard islands: Ob and Lena banks; Ant­ arctic Peninsula. These regions having been compared in terms of their ophiuroid species composition by means of similarity indexes and plotting dendrograms, four areas were shown to exist which were comparatively distinct: 1) Antarctic Shelf to Antarctic Peninsula, including Bellingshausen and Weddell seas;2) Antarctic Peninsula Shelf, shoals of South Orkney and South Shetland Islands;3) coastal waters of South Georgia, South Sandwich and Bouvet islands:4) coastal waters of Crozet, Kerguelen, Heard, Prince Edward, Macquarie islands, Ob and Lena banks. In accordance with this disposition of regions, the usual division of the Antarctic shelf into Eastern and Western Antarctic, the latter including the Bellingshausen, Amundsen, Weddell seas, has to be re-evaluated. The known ophiuroid fauna of these seas proved to be more similar to that of Eastern Antarctic seas than to that of the Antarctic Peninsula, South Shetland and South Orkney islands. In 1982, Neyelov, Permitin and Trunov, on the basis of bottom fish distribution, carne to the conclusion that the Weddell Sea should to b~. included in the Eastern Antarctic (Neyelov, Permitin, Trunov, 1982). An extended interpretation use of the name Eastern Antarctic would lead to confusion of names of geographical regions and biogeo­ graphical divisions. Therefore, until proper names are designed, the name South Polar re­ gion is proposed here for the Antarctic shelf to the Antarctic Peninsula: this is not to be confused with the South Polar Province of Briggs (1974), including coastal waters of the continent and adjacent islands, and the South Sandwich Islands. The name South Antilles region is proposed for the Antarctic Peninsula shelf and shallow waters near South Shetland and South Orkney islands: this name is derived from the South Antilles submarine Ridge. A change in the names of the two major biogeo­ graphical regions of Antarctic (successively ranked as Districts) requires a change in the names of some area types (see below) . Thus, Method 1 made it possible to establish four large biogeographic divisions. While being useful to distinguish regions of consid­ erable peculiarity and independence, the method of faunal comparison by similarity 1ndices fails to reveal the hierarchy of the regions thus created, that is, their ranks. Method 2 1S an addition to Method I, since, in evaluating the degree of endemism, it ena­ bles us to rank the regions established (Gurjanova,1962,1972) . When analysing the distribution of Antarctic and Subantarctic ophiuroids by Method 3, i.e. by comparing species areas, 19 main area types, or «geographical elements of the fauna», have been established. Prior to characteristiring particular modes or types of distribution, it is important to comment on the nomenclature.

The superposition of areas and method for d1stinguishing area types provide biogeographers with a good tool, eliminating a too-detailed splitting of a region when divid­ ing it into districts (which would mean an ecological, not a biogeographical, approach). Also, the method enables us to «objectively» distinguish the primary districts, making the first steps in the investigation much easier. The distinguishing of geographic elements of faunas based on area types is considered by Zezina (1976, p.7) to be «more progressive, as compared to the analysis based on comparing the faunas of the territories or sea bottom pre-established according to geomorphological, hydrological, hydrochemical and other environ­ mental factors». It should be noted, however, that the process of establishing type areas is complicated and to some extent subjective. In this paper the Tolmachev's definition of area is accepted (1962, p.5). «Area is the part of the earth's surface (water or bottom) where the given species or group of plants occur. The area of species combines all its concrete findings, i.e. all points on earth's surface where it was found». The «type area» is suggested to mean «a generalized area well coinciding with the areas of the species ... , characterized by similar distribution in a given region of the ocean» (Semenov, 1972, p.129). The oph1uroid fauna of Antarctic shelves and Subantarctic islands is characterized by a wide diversity of species. As a result of examining the Zoological Institute collec­ tions, a list of 72 species has been obtained, belonging to 31 genera and 8 families. With data from the literature included, the list consists of 93 species, 34 genera and 9 fami­ lies (Smirnov,1990). Biogeographical analysis of the region has been carried out by three methods: 1. By establishing arbitrarily chosen pri­ mary regions, whose species lists were then compared with one another. Recently, different slmilarity indexes are used, in particular, that by Szyrnkiewicz-Simpson (Iszs) and Czekanowski-Sorensen (Ics), together with simple methods of cluster analysis (Pesenko,1982). Actually, the «arbitrary choice» is «comparing the faunas pre-estab­ lished according to geomorphological, hydro­ logical, hydrochemical, and other factors of the environment» (Zezina,1976 p.7). The state of our knowledge about a given fauna also plays a considerable role. 2. By investigating the degree of endemism of taxa of different ranks and the origin of the faunal elements (Gurjanova,1962,1972). 3. By studying the areas, establishing the «geographical elements of the fauna», and superposing or joining the type areas in the general scheme (Kuznetsov,1936; Alekhin,1938; Starobogatov,1970: Semenov, 1972: Zezina, 1976). With the use of Method 1, 26 primary regions were established: Bellingshausen and Amundsen, Davis, Dumont d'Urville, Kosmonavtov, Lazarev, Mawson, Riiser-Larsen, Ross, Sodruzhestva, Somov, Weddell seas: South Georgia, South

478

In 1977, an attempt was made by Semenov (1977), to formalize the latitude-zonal bio­ geographical terms. Kafanov and Nesis (1982) consider that the princlple of latitude-zonal nomenclature is very informative. Unfortu­ nately, this nomenclature can be used only if the zonal limits have been previously agreed upon, and if the species «keep to» these lim­ its in their dlstribution. Because of this, when choosing the names for an area type we used mainly those names WhICh had already been established in the biogeographical literature on Antarctic by Nybelin (1947), Andriashev (1964) and Kussakin (1967). The names, where possible, are given their synonyms according to Semenov's nomenclature (Semenov,1977).

I. Endemic Antarctic Fauna Represented here are the areas corresponding

to the species distribution in coastal waters

of the Antarctic Continent, the islands of the

ScotIa Arc and Bouvet island. For the 59 Ant­

arctic endemic species, 7 area types have been

obtained by means of area superposltion:

FI«.

1. South Polar area type South Polar area type represents the water area occupied by Bellingshausen, Amundsen, Weddell, Lazarev, Riiser-Larsen, Kosmonavtov, Sodruzhestva, Davis, Mawson seas, region of 8ANZARE coast, Dumont d'Urville, Somov, Rossa and coastal waters of Balleny and Scott is­ lands (Fig.la). This area type partially cor­ responds to the East-Antarctic type of Nybelin. Twenty six ophiuroId species areas are included, 17 of them being best fit to this particular distribution type: Amphiura proposita, Amphiophiura inops, Ophiocten banzarei, o. doederleini, o. megaloplax, o. ultimum, Ophiomastus bispinosus, Ophiosteira bullivanti, O. debitor, o. echinulata, O. rotundata, Ophiura mlmaria, Ophiurolepis banzarei, o. mordax, Ophiocamax gigas, Ophiacantha paramedea, Ophiodictys inanis. NIne conventional endemic species described from antarctic coastal water have been in­ cluded in this geo~raphial faunal element. Ophiocten carina tum, Ophiomastus perforatus and Amphilepis gymnopora was found only in the Davis Sea, Ophiozonella antarctica - in the Rliser-Larsen Sea, Ophiura umltakamuruae ­ near the Scott I., Ophionotus taylori - in the Ross Sea, Ophiomastus australis, o. ludwlgi and Ophiura friglda - in the Beillngshausen Sea. o. frigida was found In the Amundsen Sea too.

I.

TII~

Snlltll roJ~r ty~~ or er~~ (n); tile I.ou I\lIt"retl~-Jt~r«u~l~" typ" or llrl!t'l (h).

Fill. 2. Th" Sout.h A"Ull~!!l' tr"~ or "r~e (.);: th". Notfll-Sllhtro~lft tr"~ or Jl.refl (b).

2. South Antllles area type arctic Peninsula and South Shetland Islands, and Ophiurolepis granulifera on the Antarctic Peninsula shelf. The South Antilles area type is close to the West Antarctic type of Nybelin or West Antarctic sensu stricta auctorum. The South Antilles type doesn't include the Bellingshausen and Weddell seas.

The South Antilles area type includes shallows near the South Shetland, South Orkney and _Antarctic Peninsula. Four species of brittle stars have this area type (Fig.2a): Amphioplus acutus, Amphiophiura gibbosa and Ophiomastus conveniens have been discovered near the Ant­

479

3. High Antarctic area type The High Antarctic area type (noteupolar of Semenov, 1977: Continental-Circumpolar type of Nybelin, 1947; Circumantarctic auctorum) has been construed as a group of areas around Antarctic Continent and shallow waters near

the South Shetland and South Sandwich islands (Fig. 3al. The following 14 specles can be considered to belong to this area type: Astrochlamys sol, Amph10plus peregrinator,

Ophiocten dubium, Ophiogona doederleini, Ophlosteira antarctica, Ophiura flexibilis, O. migrans, O. rouchi, O. serrata, Ophiuroglypha carinlfera, Ophiurolepis brevi rima, o. tuberosa, O. tumescens, Ophiacantha pentactis.

FI ... 4.

Th~ CIr~l) ... r..,nttn""l"l

tyr4 nr 'UlI!'lI (.);

Dr

'-hit L",u Anl"r~lle t)'J'" 11r~. (h): lh" K~r."ltl~" L,,..,, I)r IIrr-Il (0).

wich islands: Amphiophiura rowetti, Amphiura monorima and Ophiocten bisquamatum (Fig. 4b). The latter two are possible endemics of South Georgia Island.

rl •. J.

Th~ lh~

HI.',

Anl~rctl~

r.. t".onIAn·l.ov

lyre ~r _r~a (A); Antlllr~lle tYPl!!

or

.f'~1Il

(b),

4. Circumcontinental area type

Andriashev (19641 did not separate this type of distribution, but described areas for bot­ tom fishes, which had not been found after the limits of the Antarctic shelf. Kussakin (1967) and Averintsev (19721 named this type as Circumantarctic. One ophiuroid species has this Clrcumcontinental type of distribution ­ Ophiosparte gigas (Fig.4a).

5. Low Antarctic area type

Low Antarctlc area type (by Kussakin, 1967) corresponds to low antarctic latitude distri­ bution. Using the nomenclature of Semenov (1977) it is possible to name this type as notinferpolar. It includes 3 species WhiCh occur near South Georgia and the South Sand-

Fl •. 5. The S"IILh AnLI11 .. ,.·I.ou Anlllretle tvre or .relll (.») th.., KerCuel,,"·Soulh Ahle'" tYPlt or lu.,lIl (h).

480

6. South Antille.-Low Antarctic area type

8.

Two species (Amphiura microplax and Ophlomages cristatus) and 1 subspecies (A. microplax

Kerguelen area type of Andriashev (1964). This

dlsjuncta)

(Fig. Sa) characterize this area.

It should be noted that these taxa have not been found near Bouvet Island. The monotypic genus Ophiomages which is close to the antarc­ tic endemic genus Ophiosteira is limited in its distribution South Antilles-Low Antarctic

Kerguelen area type

type includes areas of 6 species of brittle stars which occur off Prince Edward, Crozet, Kerguelen, Heard islands, Lena and Ob banks

(Fig. 4c). Ophiurolepis carinata has this area type. Ophiuroglypha ambigua was found near Crozet, Kerguelen and Heard; Ophiogona

7. Antarctic area type

laevigata - near Kerguelen and Heard; Ophioscolex marionis was described from Prince Edward Island; Ophiomisidium mirabile - on Ob Bank and Amphiophiura brevispina was met only near Kerguelen Island.

Nybelyn (1947) named this the Panarctic type. Pushkin (1977) named this type

III. Antarctic-Notal 9pecies

area type.

Circumantarctic. According to Semenov

(1977) it can be named notopolar. This

This group of species characterize areas which occupy both antarctic and notal waters; and most findings were made in Antarctic Zone.

type contains distinctive species of brit­ tle stars which occur found around Antarc­ tic shelf, near the Scotia Arc islands

including the South Georgia and Bouvet islands: Astrochlamys bruneus, Astrohamma tubercula turn, Amphiura deficiens, Ophionotu5 victoriae, Ophioperla koehleri, Ophiura crassa, Ophiurolepis gelida and

9. Antarctic-Patagonian area type Antarctic-Patagonian area type includes waters near the Antarctlc Continent, Scotia Arc is­ lands, coastal waters of Argentina to 40-52 degrees south latitude or Patagonian Shelf and

Theodoria relegata (Fig. 6b).

.hallows of Terra del Fuego and Falkland 19­ II. Notal species

lands

(fig.

7). Three species characterize

this area: Amphiura belgicae, Ophioplocus incipiens and Ophiomitcella falklandica.

To notal species we can refer species inhabit­ ing the Notal Zone (antiboreal, south temper­

ate) occupying the i91ands of the Kerguelen region and parts of the South American shelf.

10. Antarctic-Kerguelen area type Antarctic-Kerguelen area type occupies mainly

the Antarctic shelf,

FiliI. 6. The dl!lt.rlbutlon "r !'r~~h" A!I'.ernf'l1Jl:

tn t.h~

loY"),,1

5"uth~rn ""Plll!lrh"r" C.); Anllllret.le lyre or IIIr,," (b).

t,hll)'

481

shallow of Scotia Arc

islands and to the East at the Notal Zone, to Kerguelen and Heard islands (fig. 8). The following 4 species have thi~ distribution: Amphiura angularis, A. gaussi, Ophioleuce regulare and Ophiacantha antarctica.

to distribution in the Antarctic region, on Patagonian Shelf and near Subantarctic islands: Prince Edward, Crozet, Kerguelen and Macquarie. Antarctic-Notal type in­ cludes 6 characterisic species of brittle stars: Astrotoma agassizi, Arnphiura joubini, Ophiura meridonalis, Ophiurolepls martensi, Ophiacantha vivipara and Ophiolimna antarctica (fig. 9).

11. Antarctic-Notal area type The Antarctic-Notal area type corresponds

12. South Antilles-Low Antarctic-Kerguelen

area type

Two species of ophiuroids were found to char­ acterize this area: Arnphioplus affinis and Amphiura lymani (fig. 10). It should be pointed out that both species were found in seaweeds too, the latter among rhizOlds of Macrocystis pyrifera. Both species are vivipa­ rous, and do not have free larvae With the help of which these brittle stars could dis­ perse in this region - from Antarctic Penin­ sula shelf and coastal waters of Scotia Arc Islands to Subantarctic islands.

13. Low Antarctic-Kerguelen area type Low Antarctic-Kerguelen area type of Kussakin (1967). The only species Amphiura alternans occurs near South Georgia and Subantarctic islands (fig. 1b). As the species With the preVious type of area this brittle star was found in seaweeds near South Georgia. The type may be named South Georgian-Kerguelen type also.

rlg. 10. Tilt!

~outh Allllllf!n-Lou Anl ... rcllc-~l)rg".If!n lyre or I'IIreli.

482

IV. Notal-Antarctic species

(Fig. 12). Ophiocten amitinum belongs to this

This group of ophiuroids consists of species

distribution type. This brittle star occurs near the shores of Argentina, Terra del Fuego,

which are distributed mainly in the Notal

Falkland Islands, South Georgia and

Zone, but touch at Antarctic waters, chiefly, the Low Antarctic subzone (South Georgia re­

Subantarctic islands. O. amitinum was found

among rhizoids of kelps

(Mortensen,

1933).

gion) . V. Notal-Subtropic species 14. Patagonian-Low Antarctic area type

Areas of this type are typified by species distributed mainly in the Notal Zone and only partly spreading beyond its limits (predomi­ nantly notal area type).

Five species of brittle stars typical of this area type were found on the Patagonian Shelf and near Falkland, South Georgia and Bouvet islands (Fig. 3b). They are: Ophioscolex nutrix, Ophiolebella biscutifer, Ophiacantha ingrata, Ophiactis asperula and Ophiuroglypha

17. Notal-Subtropic area type

lymani. The first two species are vivparousi the latter two occur among rhizoids of

seaweeds (Smirnov,

Species with this distribution occur on the

1979,1982).

Patagonian Shelf, Kerguelen, Macquarie, Gough and New Zealand islands (Fig. 2b). One species is characteristic - Amphiura magellanica. is viviparous and has been found among

15. Notal-South Antilles area type

It

seaweeds off the Falkland Islands and the New Zealand (Koehler,1923; Mortensen,1924).

The Notal-South Antilles area type or Patagonian-Kerguelen-South Antilles type (Fig. 11). Two viviparous species Amphiura eugeniae and Ophionotus hexactis occur near shores of South America, islands of Kerguelen region and from Antarctic Peninsula to South Georgia Island. Both species live among seaweeds and

This type is also marked by only one species ­ Astrophiura permira (Fig. 5b). It occurs near

the latter among rhizoids of floating macrophytes (Smirnov,1979)

Heard Island (Cherbonnier,Guille,1976;

18. Kerguelen-South African area type

South Africa and was also described from the Litvinova,Srnirnov,1981) .

16. Notal-Low Antarctic area type The Notal-Low Antarctic area type or Patagonian-Kerguelen-Low Antarctic area type

Fl •. 11. The noh,J-Sollth ""t.ll1ell tYrl! or Area.

FJ«.

483

12. Thill )loll'lll· Lou Al1tflrcttc tyr" or

"r~"'.

VI. Notal-Antarctic-Subtropic species

students with a simple and easy method. It is also necessary to note that establish~ng and evaluating of type areas is still lacking a complete theoret~cal foundation. The type areas, resulting from the changes it areas in both the past and recent time, represent ag­ gregates of similar species distributions: however, the latter types could be of d~ffer­ ent origin and represent different stages in the areal dynamics (reduction or expansl0n etc). It is supposed that theoretical research on the type areas will lead to development of new methods and concepts of biogeography. The current view obtained by means of study of type areas and plotting of the generalized scheme agrees to a considerable extent with results obtained during the ophluroid distri­ bution analysis by Method I, i.e. there exist four dist~nct regions in Antarctic and Subantarctic. namely South Polar (