Michelopagurus limatulus (Henderson, 1888)

(Figs. 12, 30 B)

Pagurodes limatulus Henderson, 1888: 97, pl. 10, fig. 6 [type locality: south of the Philippines, 500 fathoms].— Alcock 1905: 107, pl. 12, fig. 6.

Paguroides sp.? limatulus . — Alcock 1901: 225.

Michelopagurus limatulus . — McLaughlin 1997: 482, figs. 13a–d, 36a–f; 2007: 311.—McLaughlin et al. 2007: 221, unnumbered figs.

Material examined. RV “Natsushima”, NT10-13 cruise, ROV “Hyper-Dolphin”, dive #1165, Northeast Nikko Seamount, 23°06.754’N, 142°21.509’E, 677 m, 23°06.754’N, 142°21.521’E, 668 m, 31 July 2010, 1 female (sl 4.8 mm), 1 ovigerous female (sl 4.3 mm), JAMSTEC 0 81526.

Coloration in life. Shield mottled with orange and white. Ocular peduncles, antennular and antennal peduncles uniformly orange; antennal flagellum proximally orangish, becoming paler in distal half. Chelipeds and ambulatory legs orange. See Fig. 12.

Distribution. Heretofore known from Indonesia, Philippines, Taiwan, New Caledonia, French Polynesia and possibly from Travancore coast of India, 209–1414 m. The present specimens represent the first record of this species from Japanese waters.

Ecology. The two specimens were found to climb colonies of a primnoid soft coral (Fig. 29 B).

Remarks. Michelopagurus is represented by two species, M. limatulus (type species) and M. chacei McLaughlin, 1997 . McLaughlin (1997) presented a rather detailed diagnosis of M. limatulus based on the holotype and newly collected samples from the Banda Sea, Indonesia. McLaughlin et al. (2007) also provided a shorter diagnosis of the species based on material from Taiwan. The present specimens agree generally with these published accounts. McLaughlin (1997) mentioned that the meri of the second pereopods bear a single or double row of spinules or tubercles on the ventral surfaces in her material. However, in the present specimens, such a row of spinules or tubercles is not seen. Similarly, the specimens from Taiwan do not have a ventral row of spinules or tubercles on the meri of the second pereopods (McLaughlin et al. 2007). We refer our specimens to M. limatulus because they agree better with that species in having 11–19 ventral spines on the ambulatory dactyli. Michelopagurus chacei has only nine to 11 ventral spines (McLaughlin, 1997).