Catapagurus tuberculosus (Asakura, 1999)

(Fig. 2A)

Icelopagurus tuberculosus Asakura, 1999: 382, figs. 1–4 (type locality: Kume Island, Ryukyu Islands).

Catapagurus tuberculosus .— Asakura 2001: 830, figs. 1D, G, 51.— Osawa & Takeda 2004: 1112.

Material examined. Ie Island, unnamed submarine cave: entrance, 25 June 2017, 1 male (sl 4.9 mm), RUMF- ZC-6031 (IE 188).

Distribution. Ryukyu Islands (Ie Island, Kume Island, and Shimoji Island) in southwestern Japan; 10–35 m (Osawa & Takeda 2004; Osawa & Fujita 2016; present study).

Habitat. Coral reefs; often found on fine sediments in submarine caves (Osawa & Takeda 2004).

Remarks. This species was originally described as Icelopagurus tuberculosus by Asakura (1999). Asakura (2001) subsequently transferred the species to the genus Catapagurus A. Milne-Edwards, 1880 from Icelopagurus McLaughlin, 1997. Catapagurus tuberculosus has been often recorded from submarine caves in the Ryukyu Islands (Osawa & Takeda 2004, Osawa & Fujita 2016; Table 2). As noted by Osawa & Takeda (2004), this species carries a gastropod shell, which protects only the abdomen and posterior carapace, being too small for the hermit crab to retract the thoracic appendages.