Nematocarcinus

Martin, Joel W. & Haney, Todd A., 2005, Decapod crustaceans from hydrothermal vents and cold seeps: a review through 2005, Zoological Journal of the Linnean Society 145 (4), pp. 445-522 : 473-474

GENUS NEMATOCARCINUS SMITH, 1884

The family Nematocarcinidae contains only three genera and approximately 39 species ( Burukovsky, 2003; Komai & Segonzac, 2005b). Most of the species are in the genus Nematocarcinus , reviewed by Chace (1986) and more recently in a series of papers in Russian by Burukovsky (e.g. 1988, 1991, 2000a, b, 2002a, b, c, 2003, 2004a, b, c; Zoologischesky Zhurnal). Members of this genus are characterized by highly elongate third, fourth and fifth pereopods. Although shrimp that resemble (and probably are) species of Nematocarcinus have been observed at several sites, including the Galapagos ( Hessler & Smithey, 1983), collections from vent or seep sites are surprisingly rare. Ohta et al. (1995) reported Nematocarcinus productus from the Enshu-nada cold seeps off Japan, but it is unclear as to whether they collected any specimens. Hashimoto & Ohta (1999) listed the genus in their table of collected and observed specimens from the DESMOS site of the Manus Basin. Specimens of the genus Nematocarcinus were included in the collections of deep-sea shrimps made by beam trawl sampling in the Antarctic by the Japanese Antarctic Research Expedition (see Komai, Takeuchi & Takeda, 1996); however, none of the material was collected from known vent sites (although the possibility exists that vents are there). One of the authors (T. Haney) observed shrimp of this genus to be the most abundant decapod species adjacent to areas of diffuse hydrothermal venting on the Eastern Pacific Rise from 08°47′N to 12°48′N during the FIELD cruise of November 2003; one specimen was collected and is housed at the Field Museum (Chicago) as FMNH 11367, collected on DSMV Alvin dive 3935 at a site of new lava flow. Shank et al. (1998a) reported Nematocarcinus ensifer ( Smith, 1882) from vents at 09°50′N. Although most records of N. ensifer are from the North Atlantic Ocean, it has been reported from the Gulf of Mexico at and below 1646 m ( Pequegnat, 1970) and from the eastern Pacific Ocean ( Faxon, 1895; Shank et al., 1998a). We include the two aforementioned species, N. ensifer and N. productus , in our review. However, these identifications are tentative and should be verified by first-hand study of material. Two new species have been described by Komai & Segonzac (2005b) from the EPR and are listed here as Nematocarcinus burukovskyi and N. ovalis (below).

Nematocarcinus burukovskyi . This new species was described by Komai & Segonzac (2005b) based on three specimens from sites along the southern EPR: 17°S (subadult male holotype, MNHN-Na 15768, 2595 m), 23°S (young paratype, CBM-ZC 8360 , 2612 m) and 31°S (female paratype, USNM unspecified, 2330 m) .

Nematocarcinus ovalis . This new species was described by Komai & Segonzac (2005b) based on a single ovigerous specimen (MNHN-Na 15765) collected from waters above hydrothermal vents at the 13°N site on the EPR at a depth of 2558–2619 m .