Retropluma denticulata Rathbun, 1932

Arzivian, Arteen, Alrubaie, Ahmad, Yang, Jessica, Lin, Huiyu, Zhang, Eva & Leong, Rupert, 2022, Crabs (Crustacea, Decapoda) from the Seas of East and Southeast Asia Collected by the RV Hakuhō Maru (KH- 72 - 1 Cruise) 4. South China Sea, Bulletin of the National Museum of Nature and Science. Series A, Zoology 48 (4), pp. 147-191 : 178

Retropluma denticulata Rathbun, 1932

( Fig. 11E )

Material examined. RV Hakuhō Maru KH-72-1 cruise, sta. 42, 1Ə (CB 7.8×CL 6.6 mm), NSMT-Cr 30943.

Remarks. The genus Retropluma was extensively studied by De Saint Laurent (1989) on six species then known, and later a new species was added by McLay (2006a). The most remarkable characteristic common to seven known species is that the last pair of the thoracic legs is extremely reduced. Even if all of the species are rather rare, R. denticulata is well known by the records from the West Pacific by Yokoya (1933), Sakai (1934, 1939, 1976), Zarenkov (1968), De Saint Laurent (1989), Chen and Xu (1991), Dai and Yang (1991), and Takeda (2001).

In R. denticulata ( Fig. 11E ), the rostrum is triangular, with a wide basal part; both of two transverse carinae of the carapace dorsal surface are wholly distinct between the carapace lateral margins of both sides.

McLay (2006a) included the new species, R. laurentae , which was preoccupied by a fossil crab and renamed R. solomonensis by McLay (2006b), in the key to six species prepared by De Saint Laurent (1989).

Distribution. Japan, South China Sea, Philippines, and Solomon Islands; 70–286 m depth.

Figures

Fig. 11. A–B: Bathypilumnus sinensis (Gordon), 8 (NSMT-Cr 30933; CB 8.7×CL 7.0mm) from sta. 45. C: Eumedonus niger H. Milne Edwards, Ə (NSMT-Cr 30935; CB 7.5×CL 7.7mm) from sta. 50. D: Incultus tuberculosus (A. Milne-Edwards), 8 (NSMT-Cr 30928; CB 25.3mm with epibranchial tubercles, CL 14.5mm) from sta. 45. E: Retropluma denticulata Rathbun, Ə (NSMT-Cr 30943; CB 7.8×CL 6.6 mm) from sta. 42. F: Lupocyclus philippinensis Semper, Ə infested by a Sacculina (NSMT-Cr 30924; CB 20.5mm including lateral teeth, CL 17.0mm including frontal teeth) from sta. 45.