Trichaster flagellifer von Martens, 1866

Baker, Alan N., Okanishi, Masanori & Pawson, David L., 2018, Euryalid brittle stars from the International Indian Ocean Expedition 1963 - 64 (Echinodermata: Ophiuroidea: Euryalida), Zootaxa 4392 (1), pp. 1-27 : 6-7

Trichaster flagellifer von Martens, 1866

( Fig. 4A–E )

Trichaster flagellifer von Martens, 1866: 87 ; Liao & Clark, 1995: 163, fig. 69. Trichaster elegans Ludwig, 1878: 59 .

Material Examined. USNM 1072573, Anton Bruun Cruise 1 Station AB39A, Andaman Sea, 14°52’N, 96°39’E, 48–64 m, 31 March 1963. 1 specimen ( Fig. 4A–E ).

Remarks. The specimen has a disc diameter of 32 mm, and arms 200 mm long, branched only five times in their distal half, the first branch occurring at 42 segments from the disc ( Fig. 4A–B ). This remote branching is a characteristic of the genus, along with longitudinal aboral, and vertical lateral, arm ridging. The disc is flat and smooth in the centre ( Fig. 4C ), with the radial shields exposed only distally as small triangles ( Fig. 4D ). There are two arm spines ( Fig. 4E ).

The specimen was taken at only 1 of 7 benthic shelf stations in the Gulf of Martaban in the northern Andaman Sea, an area near the type locality for this species (Bay of Bengal). It has, however, been found elsewhere in the tropical Indo-west Pacific Ocean, including the Arafura Sea, South China, Japan, and the Philippines, in 65–146 meters ( Liao & A. M. Clark, 1995; Rowe & Gates, 1995).

Figures

FIGURE 4. Trichaster flagellifer (USNM 1072573) (A–E) and Asteronyx luzonicus (USNM 1072474) (F–G). A, aboral view; B, oral view; C, aboral central view; D, aboral peripheral view; E, oral basal portion of the arm; F, aboral view; G, oral view.