Microgoneplax elegans ( Chen, 1998 ) Castro, 2007

Castro, Peter, 2007, A reappraisal of the family Goneplacidae MacLeay, 1838 (Crustacea, Decapoda, Brachyura) and revision of the subfamily Goneplacinae, with the description of 10 new genera and 18 new species, Zoosystema 29 (4), pp. 609-774 : 729

Microgoneplax elegans ( Chen, 1998) n. comb.

Ommatocarcinus elegans Chen, 1998: 285 , 310 [in list], 313, fig. 14.

TYPE MATERIAL. — ♂ holotype ( IOAS SSB III-34) ; ♂ paratype ( IOAS SSB 2-3 - 11 ) .

TYPE LOCALITY. — South China Sea, Nansha Is, 07°02.14’N, 108°52.29’E, 138 m.

MATERIAL EXAMINED. — Chesterfield Islands. MUS- ORSTOM 5, stn DW 296, 23°12.61’S, 159°36.27’E, 278 m, 11.X.1986, 1 ♂, cl 5.1 mm ( MNHN-B 29316).

DISTRIBUTION. — South China Sea ( Chen 1998) and now Chesterfield Is. Depth: 138- 278 m.

REMARKS

Microgoneplax elegans n. comb. was described from two males collected in the South China Sea and placed in Ommatocarcinus White, 1852 . It clearly does not belong to Ommatocarcinus , which is characterized by a G2 that is slender and slightly shorter or longer than the G1, by greatly elongated eye peduncles that may extend well beyond the outer orbital angles, and by much larger adults (see Remarks for Ommatocarcinus below). It belongs instead in Microgoneplax n. gen. on account of a G2 that is much shorter than the G1, eye peduncles that are long but slightly shorter or as long as front and not extending beyond the outer orbital angles, and a small carapace size (cl 4.0-4.3 mm). Characteristic of the species and not found among congeners, however, is a relatively wide male abdomen and a front with a small, pointed prominence ( Chen 1998: figs 14-2, 14-6).

A male specimen from the Chesterfield Is (cl 5.1 mm, MNHN-B 29316) was tentatively identified as belonging to this species. It shares the wide abdomen and the general morphology of the G1 and G2 with M. elegans n. comb. The ventral view of the G1 is nearly identical to that shown in Chen (1998: fig. 14- 7) except that the setae along the median portion are longer in the Chesterfield Is specimen than the setae shown in the figure.Dorsally, however, the G1 shows a carina-like, crested thickening along its median portion that is not shown in the figure, which unfortunately only shows the ventral surface. Another difference is the front, shown by Chen (1998: fig. 14-2) to have a small median prominence that was not found in the Chesterfield Is specimen. The type material (at IOAS) was not available for examination.