Freshwater Ostracoda (Crustacea)

113 downloads 0 Views 1MB Size Report
Hebrides” (Victor & Fernando 1978) comes from a different island. That other island of Futuna, sometimes called West Futuna to distinguish it from the French ...
Freshwater Ostracoda (Crustacea) collected from the islands of Futuna and Wallis, Pacific Ocean, with a checklist of the non-marine Ostracoda of the Pacific Islands Claude Meisch1, Nathalie Mary-Sasal2, Jean-Paul Colin3 & Karel Wouters4 Musée national d’histoire naturelle, 25, rue Munster, L-2160 Luxembourg ([email protected]) 27, avenue du Maréchal Joffre, F-66200 Corneilla del Vercol ([email protected]) 3 3, impasse des Biroulayres, F-33610 Cestas ([email protected]) 4 Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels ([email protected]) 1 2

Meisch, C., N. Mary-Sasal, J.-P. Colin & K. Wouters, 2007. Freshwater Ostracoda (Crustacea) collected from the islands of Futuna and Wallis, Pacific Ocean, with a check-list of the nonmarine Ostracoda of the Pacific Islands. Bulletin de la Société des naturalistes luxembourgeois 108: 89-103. Abstract. The freshwater Ostracoda collected during a survey carried out in October 2004 on the French islands of Futuna and Wallis, Polynesia, Pacific Ocean, are presented. In total, 10 species were found, of which 5 could be identified to the species level. Notes on the taxonomy of the species are provided. Parastenocypris perarmata (Brady, 1904) McKenzie, 1971 is transferred into the genus Chrissia Hartmann, 1957: Chrissia perarmata (Brady, 1904) comb. nov. Scanning electron micrographs of Strandesia vinciguerrae (Masi, 1905) and Cypretta seurati Gauthier, 1929 are presented. A check-list of the non-marine Ostracoda of the Pacific Islands (Oceania minus Australia and New Zealand) is given. Key words. Ostracoda, Crustacea, Pacific Islands, Polynesia, Futuna, Wallis, freshwater, non-marine.

1. Introduction Wallis and Futuna is a small archipelago located in the South Pacific Ocean, west of Samoa and north-east of Fiji (fig. 1). The archipelago is part of the so-called Pacific Islands, which together with Australia and New Zealand form the geographic region commonly designated as Oceania. In October 2004 one of us (NMS) carried out an extensive survey of the freshwater habitats of Futuna and Wallis. That investigation aimed at improving the knowledge of the flora, the fauna and the environmental conditions of the freshwater ecosystems of the two islands. In the present contribution we present the Ostracoda (Crustacea) collected in the course of that survey. No freshwater ostracods had formerly been reported from the islands of Futuna and Wallis. Indeed, the record of Hemicypris futunaensis Victor & Fernando, 1978, which was collected from “a large hole in Bull. Soc. Nat. luxemb. 108 (2007)

a lump of coral, Mission Bay, Futuna, New Hebrides” (Victor & Fernando 1978) comes from a different island. That other island of Futuna, sometimes called West Futuna to distinguish it from the French Futuna, is part of the Republic of Vanuatu (the Vanuatu archipelago was designated as The New Hebrides before acquiring its independence in 1980). While the marine ostracods from the Pacific Islands are relatively well known, only a relatively small number of publications deals with their non-marine fauna (see references in table 4). Hartmann (1984) was the first to publish a check-list of both marine and non-marine ostracods known from the Pacific Islands. Hartmann’s (op. cit.) list comprised 20 nonmarine ostracod species. More recently, Eldredge & Miller (1997) provided a list of the freshwater invertebrates, the ostracods included, of Hawaii, while Colin 89

140°E 10°N

150°E

160°E

170°E

180°

170°W

160°W

150°W

140°W

130°W 10°N

Marshall Islands 0°



Papua New Guinea

Kiribati Solomon islands

10°S

Wallis and Vanuatuu

20°S

10°S

Samoa Islands

Futuna

French

Fiji

Tahiti Tonga

New Caledonia

Cook islands

Polynesia

20°S

Australia 30°S

30°S

New Zealand 40°S 140°E

40°S 150°E

160°E

170°E

180°

170°W

160°W

150°W

140°W

130°W

Fig. 1. Location of Wallis and Futuna in the Pacific Ocean.

(2002) and Colin & Hoibian (2003) published annotated check-lists of the non-marine ostracods from French Polynesia, Clipperton, and New Caledonia, respectively. In the absence of any comprehensive faunistic synopsis and in order to facilitate future research, we here present an updated checklist of the non-marine ostracods recorded from the Pacific Islands (table 4).

2. Material and methods 2.1. Study area

Fig. 2. Maps of Futuna and Wallis with sampled localities.

90

Wallis and Futuna, officially the Territory of Wallis and Futuna Islands (French: Wallis-etFutuna or Territoire des îles Wallis-et-Futuna) consists of the three following main islands: Wallis (77.5 km²) on the one side, and Futuna and Alofi (64.5 km² in total) on the other side. While Futuna and Alofi are close to each other (1.8 km), Wallis is located 230 km northeast of the former two islands. Within Oceania, the archipelago belongs to the geographical region designated as Polynesia. Wallis (also called Uvea Island) and Futuna are situated in the southern tropics, at latitudes of 13° S and 19° S, respectively. The climate is warm, with an annual average Bull. Soc. Nat. luxemb. 108 (2007)

Table 1. List of species collected from Futuna (F) and Wallis (W). Stenocypris major (Baird, 1859) Daday, 1898 Stenocypris malayica Victor & Fernando, 1981 Chrissia cf. perarmata (Brady, 1904) McKenzie, 1971 Strandesia vinciguerrae (Masi, 1905) G.W. Müller, 1912 Cypretta seurati Gauthier, 1929 Cypridopsis vidua (O.F. Müller, 1776) Brady, 1867 Alicenula cf. serricaudata (Klie, 1935) Rossetti & Martens, 1998 Candonopsis sp. juv. Cyprididae sp. juv. Cytheroidea sp.

F F

W W W W W W W

F F F F

W W

Table 2. List of localities and species recorded. S. S. C. cf. S. vinciC. major malayica perarm. guerrae seurati

C. vidua

A. cf. Candon-­ Cyprid­ Cytherserric. opsis sp. idae sp. oidea sp.

Futuna Leava Sausau Sausau taro f. Gutuvai Lake Nuku

×

× × × ×

×

× ×

× × × × ×

×

Wallis Alofivai Lano Lalolalo Kikila 1 Kikila 2 Lanutavake Ha’atofo Mala’e fo’ou

× × × × × ×

× ×

× × × ×

× ×

× ×

of 27°C in Wallis, 26°C in Futuna, humid, and subject to tropical cyclones. The annual temperature amplitude is very low (1°C). Rainfall is abundant, with over 3 m in 260 days, from approximately October to May, on Wallis and up to 4 m on Futuna. There is significant seasonal variation and, though there is no ‘true’ dry period, a strong rainy season occurs between October and May. The rainiest month on Wallis is December, with three times more abundant rain falls than in August (Angleviel et al. 1994). Although the three islands are volcanic in origin, they differ in their geologic history and have therefore developed different geoBull. Soc. Nat. luxemb. 108 (2007)

× × ×

×

×

×

×

×

morphological characteristics (Angleviel et al. 1994; Malau et al. 1999). Wallis: due to the extreme permeability of the soils and a weak relief (highest point 151 m asl), there are no surface streams. However, there are several lakes, located in depressions (Alofivai, Kikila) and craters (Lano, Lalolalo, Lanutavake). Only little information is available on the lakes: for example, lake Lalolalo is supposed to be 80 meters deep. Futuna and Alofi have a more pronounced relief. Futuna is about 20 km long, with a maximum width of 5 km. The longitudinal mountain range reaches its highest point at 524 m (Mount Puke), its slopes have been 91

cut down into valleys by numerous short, permanent rivers. Alofi is a small island, without permanent surface waters; it was not explored during the survey in 2004. 2.2. Sampling The sampling was carried out in the period immediately preceding the heavy rains, from 5 to 23 October 2004. All together, 24 sites (rivers, lakes, springs and taro paddy fields) were investigated, of which 13 yielded ostracods (table 2). On Futuna (fig. 2), the following 15 localities were visited: Lake Nuku, the taro fields of Leava and Sausau, and the rivers Vainifao

(lower, middle and upper courses), Galoli (middle course), Leava (lower and middle courses), Vailasi (middle course), Gutuvai (lower course), Sofala (lower course), Sausau (lower and middle courses), and Vainui (lower course). Ostracods were collected from five of these sites (table 2). On Wallis (fig. 2) the following nine localities were investigated: the lakes Kikila, Alofivai, Lanutavake, Lalolalo and Lano; the taro fields of Ha’atofo, Mala’e fo’ou and Falaleu, and the freshwater spring of Vaitauolo, close to the coast. Ostracods were retrieved from eight of these sites (table 2). At each locality, a number of physico-chemical parameters were registered (table 3). The ben-

Table 3. Physico-chemical parameters of the investigated sites on Futuna and Wallis. NTU = nephelometric turbidity index; COD = chemical oxygen demand; BOD = biochemical oxygen demand; NO3, Cl, etc in mg/L. Dates Localities Coord. T°C O2 O2 pH Cond. Turb. NO3 Cl Ca Mg SO4 K Na COD BOD5 2004 GPS WGS 84 % mg/L µS/cm NTU Futuna 14/10 Leava taro field 16/10 Gutuvai riv. low. course 16/10 Sofala river low. course 19/10 Sausau taro field 20/10 Nuku lake

S 14.292 W 178.158 S 14.308 W 178.129 S 14.272 W 178.117 S 14.288 W 178.167 S 14.281 W 178.154

28.1 96 7.49 9.3 187

8.93