MONACANTHIDAE Monacanthus chinensis, 5.9 cm SL (photo by Seishi Kimura) Monacanthus chinensis, 7.7 cm SL (photo by Ukkrit Satapoomin) Monacanthus chinensis (Osbeck, 1765) Fanbellied Leatherjacket D II + 28-30; A 27-30; P1 12. Body very deep. Dorsal profile of snout concave. Pelvic terminus prominent, composed of 3 segments of encasing scales, movable dorsoventrally; ventral flap enlarged. Upper caudal fin rays produced into a filament. Color: body light brown with many irregular dark brown blotches. Size: maximum 38 cm. Distribution: west coast of Malay Peninsula and tropical West Pacific from Thailand eastward to New Guinea. Remarks: occurring in seagrass bed and rocky reefs in shallow waters.