Ethusa indonesiensis Chen, 1997

Castro, Peter, 2005, Crabs of the subfamily Ethusinae Guinot, 1977 (Crustacea, Decapoda, Brachyura, Dorippidae) of the Indo-West Pacific region, Zoosystema 27 (3), pp. 499-600 : 530

publication ID	https://doi.org/ 10.5281/zenodo.5399909
persistent identifier	https://treatment.plazi.org/id/264A053E-4E33-B53B-71C0-FE8773F2C29C
treatment provided by	Marcus
scientific name	Ethusa indonesiensis Chen, 1997
status

Treatment

Ethusa indonesiensis Chen, 1997 View in CoL

Ethusa indonesiensis Chen, 1997: 619 View in CoL , fig. 4.

TYPE MATERIAL. — Holotype: cl 7.3 mm, cw 7.1 mm, KARUBAR, stn DW 18 (MNHN-B 22888).

TYPE LOCALITY. — Indonesia, Kai Islands, 05°18’S, 131°41’E, 205- 212 m.

MATERIAL EXAMINED. — Philippine Islands. Bohol, Balicasag island, off Panglao island , 50-500 m, 28.XI.2001, 1 ( ZRC 2001.0517 View Materials ) ; local shell fishermen, tangle nets, 200-300 m, VI.2002, 1 ( ZRC 2002.0646 View Materials ), 1 ( ZRC 2002.0647 View Materials ). — Tangle nets of local fishermen, 25-30.VII.2003, 1 ( ZRC 2004 View Materials .0599). — Maribohoc Bay , tangle nets, 100- 300 m, T. J. Arbasto coll., XI.2003 - IV.2004, 1, 1 ( ZRC) .

Indonesia. Kai Islands, KARUBAR, stn DW 18, 05°18’S, 131°41’E, 205-212 m, 24.X.1991, 1 holotype ( MNHN-B 22888).

? Solomon Islands. SALOMON 1, stn CP 1786, 09°21.3’S, 160°24.6’E, 387 m, 30.IX.2001, 1 juv. cl 3.2 mm, cw 2.8 mm ( MNHN-B 28706).

French Polynesia. Marquesas Islands, MUSORSTOM 9, stn CP 1238, 09°41’S, 139°04’W, 280-370 m, 31.VIII.1997, 1 ( MNHN-B 28545).

DISTRIBUTION. — Known from Indonesia (Kai Is) ( Chen 1997) and now from the Philippine Is and French Polynesia (Marquesas Is) ; questionably from the Solomon Is. Depth: 200-387 m ( Fig. 34 View FIG ); also collected from nets lowered to 50-500 m.

SIZE. — Maximum size: cl 7.6 mm, cw 7.6 mm ( MNHN-B 28545), cl 9.7 mm, cw 9.7 mm ( ZRC).

REMARKS

Chen (1997: 619) pointed out that Ethusa indonesiensis was closer to E. paraygmaea Chen, 1993 , another small-size and uncommon species so far known only from two males. Both species are best separated by the shape of their G1: each having a knife-like tip in E. indonesiensis ( Chen 1997: fig. 4g-i) in contrast to a foot-like tip in E. parapygmaea ( Chen 1993: fig. 12e). The outer orbital teeth are clearly wider in E. indonesiensis ( Chen 1997: fig. 4a) than in E. parapygmaea ( Chen 1993: fig.12a). E. parapygmaea is very close to E. pygmaea Alcock, 1894 , and only the study of the type material of the later may clarify their differences (see discussion of E. pygmaea below). Also characteristic of E. indonesiensis are the relatively long P2 and P3 and the greatly enlarged propodi of the chelipeds ( Chen 1997: fig. 4b), probably only characteristic of males.

A very small juvenile with undeveloped G1 and soft exoskeleton collected from the Solomon Is (cl 3.2 mm, cw 2.8 mm, MNHN-B 28706) was questionably identified as E. indonesiensis on account of the shape of the anterior border of the carapace. The anterior border of the endostome, however, extended above the antennular fossae of the basal antennular articles, in contrast to the other known specimens of E. indonesiensis , where the anterior border only extends below the fossae.