Ethusa crosnieri Chen, 1993

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 : 518-519

Ethusa crosnieri Chen, 1993

Ethusa crosnieri Chen, 1993: 317 (key), 319, fig. 2.

TYPE MATERIAL. — Holotype: cl 6. 5 mm, cw 6.5 mm, MUSORSTOM 5, stn DW 296 ( MNHN-B 19063 ); allotype: cl 8.6 mm, damaged, MUSORSTOM 5, stn DW 256 ( MNHN-B 19068 ); paratypes:, MUSORSTOM 5, stn DW 256 ( IOAS); cl 7.3 mm, cw 7.0 mm, MUSORSTOM 5, stn DW 298 ( MNHN-B 19065 ).

TYPE LOCALITY. — Coral Sea, Chesterfield Islands, 23°12.61’S, 159°36.27’E, 178 m.

MATERIAL EXAMINED. — Chesterfield Islands. MUSORSTOM 5, stn DW 256, 25°18.00 ’S, 159°52.70’E, 290-300 m, 7.X.1986, 1 allotype ( MNHN-B 19068). — Stn DW 296, 22°12.61’S, 159°36.27’E, 178 m, 11.X.1986, 1 holotype ( MNHN-B 19063). — Stn DW 298, 22°44.00’S, 159°22.00’E, 320 m, 11.X.1986, 1 paratype ( MNHN-B 19065).

DISTRIBUTION. — Known only from the Chesterfield Is. Depth: 178-320 m ( Fig. 34 ).

SIZE. — Maximum size: cl 7.3 mm, cw 7.0 mm (MNHN-B 19065), cl 8.9 mm, cw 10.0 mm (MNHN-B 19068) ( Chen 1993: 320).

REMARKS

Ethusa crosnieri is known from only four specimens, three males and one female. Diagnostic to this species are slender and outwardly directed outer orbital teeth that typically reach beyond the frontal teeth. The endostome is relatively short, with an anterior border that extends to the level of the antennular fossae of the basal antennular articles. The anterior border of the endostome extends well below the antennular fossae in E. indica Alcock, 1894 ( Sakai 1976: 62, 63 [key]; Chen 1985: fig. 9a), a species that also has slender outer orbital teeth that usually reach beyond the frontal teeth. Ethusa crosnieri is close to E. minuta Sakai, 1937 , from which it is best distinguished by the morphology of its G1 ( Chen 1993: fig. 2h).

Figures

FIG. 34. — Bathymetric distribution of Indo-West Pacific ethusine crabs.