Actumnus setifer (De Haan, 1835)

Manikandan, K, Megalaa, N, Valliappan, Subramanian, Nandini, K, Rani, Lourdu V, Dakshinamurthi, Senthil & Nagappan, Nagappan, 2022, Crabs (Crustacea, Decapoda) from the Seas of East and Southeast Asia Collected by the RV Hakuhō Maru (KH- 72 - 1 Cruise) 3. Sahul Shelf, Bulletin of the National Museum of Nature and Science. Series A, Zoology 48 (2), pp. 35-83 : 66

Actumnus setifer (De Haan, 1835)

Material examined. RV Hakuhō Maru KH-72-1 cruise, sta. 29, 1Ə ( CB 5.2×CL 4.3 mm), NSMT-Cr 30740. — Sta. 32, 1Ə ( CB 5.0×CL 4.1 mm), NSMT-Cr 30741.

Remarks. The carapace of Actumnus setifer (De Haan, 1835) is wholly covered only with short tomentum, leaving linear interregional furrows. Both chelipeds are different in size, being covered with dense small granules, short thick tomentum and scant longish silky setae. The ambulatory legs are stout and covered with dense tomentum and longish setae similar to that of the chelipeds, with a dense fringe of setae along the anterior margin of the last leg. Takeda and Komatsu (2017: fig. 6C–D) included photographs of a female of A. setifer for comparison with the new species, A. tsurukaii .

This species has been recorded from many localities across the Indo-West Pacific under the names of A. setifer (De Haan, 1835) or A. tomentosus Dana, 1852, and sometimes simultaneously in the same paper, as seen in the papers by A. Milne-Edwards (1865), Alcock (1898), Grant and McCulloch (1906), Klunzinger (1913) and Rathbun (1924). As recorded by Laurie (1906) for this species (under two varieties, setifer and tomentosus ), A. setifer is considerably variable in the convexity, areolation, setation and anterolateral armature of the carapace.

Distribution. Whole Indo-West Pacific, with bathymetric records from 10 to 200 m. Davie (2002) recorded this species as near circum– Australian, "on coral and rocky reefs, from low intertidal to 200 m depth."