Crinitocinus alcocki ( Borradaile, 1902 )

Crinitocinus alcocki ( Borradaile, 1902) View in CoL [NJn: Tsubu-kebukagani]

( Fig. 4F View Fig )

Pilumnus alcocki Borradaile, 1902, p. 248 , fig. 48. — Rathbun, 1911, p. 230. — Ng et al., 2008, p. 141 (in list).

Crinitocinus alcocki View in CoL : Ng & Rahayu, 2014, p. 16 View Cited Treatment , figs. 9–11, 12A–C, 40E–H. — Naruse & Maenosono, 2019, p. 170 (in comparative material), fig, 8B. — Ng & Lin, 2023, p. 111 View Cited Treatment , figs. 1E–F, H, 8.

Material examined. ɹ Chichi-jima Is. — Off Futami Bay , Chichi-jima I., from stomach contents of sidespot goatfish [Jn: Ryukyu-himeji], Parupeneus pleurostigma (Bennett) , 1 juv. (cb 4.7×cl 3.8 mm), NSMT-Cr 32389, date unrecorded, collected by Y. Kurata.

Remarks. The specimen obtained from fish stomach contents is juvenile and at poor condition, without both chelipeds and some ambulatory legs. However, the carapace shape and dorsal areolation are distinctly kept and show the specific character of Pilumnus alcocki , which was deeply studied and designated as the type species of the monotypic new genus Crinitocinus by Ng and Rahayu (2014). In the specimen examined, the hairs of the carapace, chelipeds and ambulatory legs are mostly fell out together with mucus in fish stomach, but the long and oblique orbit that is as long as the whole length of the frontal margin, the anteriorly elongated mesogastric and protogastric regions, and the three lobiform teeth of the carapace anterolateral margin are clearly observable ( Fig. 4F View Fig ). Ng and Rahayu (2014) gave the fine photographs of the type and some additional specimens to redeem the inaccurate original figure about the carapace proportion. The present specimen agrees well especially with a photograph of a male (4.5× 4.3 mm) from Amirante ( Ng and Rahayu, 2014, fig. 10A).

Distribution. Amirante Islands, Seychelles, 52–70 m; Suvadiva Atoll, Maldives, 36 m; Papua New Guinea, 20 m; Off Oahu, Hawaii, from stomach of goatfish, Parupeneus multifasciatus (Quoy & Gaimard) ; Taiwan. New to Japanese waters.