Gerard Marquet

FRESHWATER CRUSTACEANS OF FRENCH POLYNESIA: TAXONOMY, DISTRIBUTION AND BIOMASS (DECAPODA)

La peche electrique pratiquee dans les eaux interieures des cinq archipels de la Polynesie francaise a permis dinventorier 16 especes de crustaces deaux douces. Parmi les 16 especes mentionnees dans le present article, une espece est endemique: Caridina rapaensis de Rapa et de Rurutu. Six sont localisees dans la region Pacifique et neuf dans la region Indo-Ouest Pacifique. Une nouvelle espece a ete trouvee: Macrobrachium sp. Elle colonise les rivieres de Moorea et des iles marquisiennes. Trois nouvelles especes ont ete pechees pour la premiere fois en Polynesie francaise: Caridina serratirostris (Moorea et Tubuai), Ptychognathus easteranus (Rurutu et Hiva Oa), Varuna litterata (Tahiti et Moorea). La repartition altitudinale de ces 16 especes dans les iles etudiees a ete etablie et la biomasse des principales especes dans les rivieres de Tahiti-Moorea a ete calculee.

Stiphodon mele n. sp., a new species of Freshwater goby from Vanuatu and New Caledonia (Teleostei, Gobiidae, Sicydiinae), and comments about amphidromy and regional dispersion

Keith P., Marquet G. & Pouilly M. 2009. — Stiphodon mele n. sp., a new species of Freshwater goby from Vanuatu and New Caledonia (Teleostei, Gobiidae, Sicydiinae), and comments about amphidromy and regional dispersion. Zoosystema 31 (3): 471-483. ABSTRACT Stiphodon mele n. sp. is described on the basis of material collected from Vanuatu and New Caledonia. It is distinguished from all other congeners in having 9 segmented rays in the second dorsal fin, usually 13 pectoral rays, 36–41 fine tricuspid premaxillary teeth, 2 small symphyseal teeth in female vs. 2–4 stout teeth in males, predorsal scales absent, and low number of scales in transverse back (3–7) and lateral series (14–21). This new species spawns in freshwater, the free embryos drift downstream to the sea where they undergo a planktonic phase, before returning to the rivers to grow and reproduce: it is an amphidromous species. As many other Sicydiinae, Stiphodon mele n. sp., is endemic to Vanuatu and New Caledonia. Numerous factors occur to control the dispersion of the amphidromous species. It is necessary to consider all of these factors to explain the existence of many endemic species and the broad or small distribution of the species in the Indo-Pacific area. The management and the conservation of Stiphodon mele n. sp. have to be necessarily regional.

Discovery of the freshwater genus Sicyopus (Teleostei: Gobioidei: Sicydiinae) in Madagascar, with a description of a new species and comments on regional dispersal

In the Indo-Pacific area, insular rivers are mainly colonized by gobiids of the Sicydiinae subfamily. These species spawn in freshwater, where the free embryos drift downstream to the sea before returning to rivers to reproduce; they are amphidromous. These gobies are the greatest contributors to the fish diversity and have the highest levels of endemism. Among the nine known genera of Sicydiinae, only two have been found in the West Indian Ocean, and only one (Sicyopterus) is known from Madagascar. Recently, two surveys discovered a new species in the genus Sicyopus. Sicyopus lord sp. nov. differs from other species by a combination of characters that includes a particular colour pattern, similar in both sexes; more scales than its congeners in lateral series (35–43), transverse back series (12–18) and a shorter caudal fin length in male fish. This paper describes the new species and discusses the presence of this genus in Madagascar.

When molecules and morphology work together: lines of evidence for the validity of Caridina buehleri Roux (Crustacea : Decapoda : Atyidae) and for C. gueryi Marquet, Keith & Kalfatak as its junior synonym

Abstract. The taxonomy of the freshwater shrimps Caridina (Atyidae) is very complex and confused mostly because the morphological characters that have traditionally been used for species delimitation and identification are highly plastic. There is thus a need for an integrative approach to their taxonomy. In total, 42 specimens belonging to either Caridina buehleri Roux, 1934 or Caridina gueryi Marquet, Keith & Kalfatak, 2009 were examined. We combined here morphological data from 12 specimens from the whole distributional range of the species, including type specimens with 16S mtDNA analyses from seven freshly sampled specimens, to verify the specific status of Caridina buehleri from Papua New-Guinea, Central Sulawesi, Western Samoa and the Solomon Islands, and C. gueryi from Vanuatu. The comparison of 24 morphological characters showed that morphological variations of character traits between C. gueryi and C. buehleri are widely overlapping and that no morphological feature can effectively split specimens into two clear groups. Molecular characters corroborated these results, as specimens from both groups were only separated by a 2% p-distance, a genetic distance that is coherent with their potentially high dispersal abilities. We thus consider C. gueryi as a junior synonym of C. buehleri. Finally, C. buehleri is characterised mainly by a styliform and characteristically indented rostrum and a long stylocerite. Detailed re-descriptions of the type specimens of C. buehleri and C. gueryi are given, as well as their geographical and ecological distribution.

CARIDINA GUERYI, A NEW SPECIES OF FRESHWATER SHRIMP (DECAPODA, ATYIDAE) FROM SANTO ISLAND, VANUATU

A new species of freshwater atyid shrimp, Caridina gueryi sp. nov. from Santo Island, Vanuatu, is described and illustrated herein. C. gueryi is similar to Caridina longirostris H. Milne Edwards, 1837, by its long rostrum, small eggs are of similar size, the termination of the telson in a posteromedian projection, the preanal carina with a distinct spine, and, in males, the appendix interna being clearly visible on the endopod of the first pleopod. However, both species can easily be distinguished as C. gueryi sp. nov. has a long stylocerite, always overreaching the basal segment of the antennular peduncle and lacks subapical teeth on the rostrum. Une nouvelle espece de crevette deau douce atyide, Caridina gueryi sp. nov. de lile de Santo, Vanuatu, est decrite et illustree ici. C. gueryi ressemble a C. longirostris H. Milne Edwards, 1837 par son long rostre, la taille petite de ses œufs, son telson se terminant par une dent subapicale, sa carene preanale avec une epine bien nette et son appendice interne bien visible sur lendopode du premier pleopode chez le mâle. Elle differe toutefois de cette espece par un long stylocerite depassant toujours larticle basal du pedoncule antennulaire et par labsence de dents apicales sur le rostre.

Description of a new species of Caridina (Crustacea: Decapoda: Atyidae) from two Micronesian islands (Guam and Babeldaob)

During field trips to Guam and Babeldaob Islands in Micronesia, freshwater shrimps were sampled and assigned either to Caridina brachydactyla De Man, 1908 or C. mertoni J. Roux, 1911 (Decapoda: Atyidae), following previous inventories. In combining morphological data with a genetical analysis, it appeared that all the specimens belonged to a new species, Caridina variabilis sp. nov., here described with its distribution. The status of this new species is clarified and finally, neither C. brachydactyla, nor C. mertoni occur in these two islands. DNA sequences of 16S were obtained from the syntypes of C. mertoni.

Taxonomy and distribution of Caridina similis Bouvier, 1904 (Decapoda, Atyidae) from the Seychelles Islands

[The taxonomic status of Caridina similis Bouvier, 1904 has been clarified using specimens recently caught from the type locality. One lectotype and five paralectoptypes of C. similis are designated to stabilize the species systematics. This species is endemic for the Seychelles Islands (Indian Ocean). Le statut taxonomique de lespece Caridina similis Bouvier 1904 est clarifie sur la base de specimens captures recemment dans la localite type. Un lectotype et cinq paralectotypes de C. similis sont designes pour stabiliser sa systematique. Cette espece est endemique des iles Seychelles dans lOcean Indien., The taxonomic status of Caridina similis Bouvier, 1904 has been clarified using specimens recently caught from the type locality. One lectotype and five paralectoptypes of C. similis are designated to stabilize the species systematics. This species is endemic for the Seychelles Islands (Indian Ocean). Le statut taxonomique de lespece Caridina similis Bouvier 1904 est clarifie sur la base de specimens captures recemment dans la localite type. Un lectotype et cinq paralectotypes de C. similis sont designes pour stabiliser sa systematique. Cette espece est endemique des iles Seychelles dans lOcean Indien.]