By Seishi Kimura

Chiloscyllium griseum

Chiloscyllium punctatum

Small sharks; maximum size about 1.0 m, smaller than 70 cm in most species. Body somewhat elongated, cylindrical; head cylindrical or weakly depressed; precaudal tail (distance from posterior end of pelvic-fin base to origin of lower lobe of caudal fin) somewhat longer than head and trunk (distance from tip of snout to posterior end of pelvic-fin base). Nostrils with barbels; nasoral grooves and circumnarial grooves present. Mouth small, located well anterior to eye; teeth small, not blade-like, monocuspid, similar in both jaws. Eyes without nictitating eyelids. Spiracles large, situated behind and below eyes. Five small gill slits, the posterior 3 over the pectoral-fin base. Two dorsal fins without spines; first dorsal-fin origin above or posterior to pelvic-fin base; second dorsal fin almost same shape and size as the first, well anterior to anal-fin origin; anal-fin base connected with caudal fin, with a deep notch between the fins; caudal fin strongly asymmetrical, with a strong subterminal notch. Vertebrae 151-192. Color: head and body dark gray or brown dorsally, whitish ventrally; body with dark spots or dark bands in some species.

Similar families occurring in the area. Hemiscylliidae is distinguished from other Indo-Pacific orectolobiform shark families in having almost cylindrical body, a long precaudal tail (longer than head and body), second dorsal fin located anterior to anal fin, and anal-fin base connected with lower lobe of caudal fin. Ginglymostromatidae and Stegostomatidae: precaudal tail shorter than head and trunk, no circumnarial grooves; anal fin separated from caudal fin.

Remarks. Occurring in tropical and subtropical coastal areas, from Madagascar to Japan and Australia. Bottomdwellers. Feed usually on crustaceans and small fishes.