The scaleless body is covered with extremely thick, elastic skin. The caudal fin is replaced by a rudder-like structure called 'clavus'. Dorsal and anal fins very high with short base; in swimming, these fins are flapped synchronously from side to side and can propel the fish at surprisingly good speed. Pectorals small and rounded, directed upward (Ref. 6885). Mouth very small; teeth fused to form a parrot-like beak. Gills 4, a slit behind the last; gill openings reduced to a small hole at the base of the pectoral fins. Gas bladder absent in adults.

Description: Characterized further by deep and oval body, nearly circular, depth 1-1.5 in TL; rough texture of skin; clavus supported by about 12 fin rays, of which 8-9 bear ossicles (Ref. 90102).