TETRAROGIDAE Richardsonichthys leucogaster, 5.1 cm SL (photo by Ukkrit Satapoomin) Richardsonichthys leucogaster (Richardson, 1848) Whitebellied Rougefish D XII-XIV, 5-9; A III, 6; P1 14-16. Body oblong, not strongly compressed. Head profile rounded. Lacrimal with two spines. Uppermost preopercular spine strongly developed. Dorsal fin origin over posterior one-third of eye; first spine more than half length of second spine. Body entirely without scales, except for lateral line. Caudal fin rounded, without elongate outer rays. Color: highly variable, but ventral body, and pectoral, pelvic, anal and caudal fins usually reddish. Size: maximum standard length 6.6 cm. Distribution: widely distributed in the Indo-West Pacific, from Zanzibar and Seychelles east to New Caledonia. Remarks: occurs on sandy bottoms or among corals in shallow waters to 90 m depth.