Rhinobatidae
by J. D. McEachran and C. Capape
Small to medium-sized shark-like rays (to 1.5 m TL), the tail moderately stout to stout, not distinctly marked off from disc, with folds along lower part of sides. Snout wedge-shaped, from obtusely angled and only moderately produced, to acutely angled and greatly produced. Nostrils with (without in some) lobe-like expansions of anterior margin separate from each other and from upper lip, or these expansions united to form a single broad subquadrangular curtain, free hind edges of which is close to upper lip. Mouth straight to slightly arched; teeth numerous and pavement-like. Two large dorsal fins, the first beginning behind hind tip of pectoral fins; these moderately expanded, attached to sides of head from level of nostrils to level of mid-part of snout and reaching to origin of pelvic fins or slightly beyond; pelvic fins not broadly expanded, margins convex, quite separate from pectoral fins; caudal fin well developed, with a slightly upturned axis, but without a definite lower lobe. Body and fins densely covered with small denticles, upper surface with thornlets or thorns around inner margin of orbits, between spiracles, on nape and shoulders and along midline of disc and tail.
Benthic on soft bottoms, generally in shallow water, but sometimes to depths of 110 m, also entering estuaries and freshwater in all tropical and warm temperate areas (but not reported from islands of the western Pacific). Ovoviviparous, females containing 4-15 embryos. Feeding on small fishes, crustaceans, molluscs and other invertebrates. Rather inactive, swimming slowly over the. bottcm by undulating their stout tails, or partially buried.
Genera 4 (up to 7 by some authors); in Clofnam area 1.
Recent revisions: Norman (1926), Bigelow and Schroeder (1953, on regional basis).