By Seishi Kimura

Himantura gerrardi

Himantura jenkinsii

Himantura walga

Neotrygon kuhlii

Taeniura meyeni

Urogymnus asperrimus

Medium to large sized batoid rays (0.4-5 m in total length, ca. 0.2-2 m in disc width). Head, trunk, and greatly enlarged pectoral fins fully fused to form a strongly flattened circular, oval, or rhomboidal disc; tail elongated, whip-like. Head not projecting from disc; eyes and spiracles on the dorsal surface of disc. Five pairs of gill openings located on ventral side of disc. Usually denticles, thorns (small spines), and/or tubercles present on dorsal surface of body disc and tail in adults. In most species, tail with 1-4 stout venomous barbed spines on dorsum. Color: body grayish or brownish dorsally, paler ventrally in most species; in a few species with bluish, blackish, or whitish spots, rings, or reticulations.

Similar families occurring in the area. Dasyatidae is distinguished from the following similar families in having an elongated whip-like tail (usually longer than disc width) and no dorsal or caudal fins. Torpedinidae and Narcinidae: stout tail with dorsal and caudal fins. Rajidae: tail with dorsal and/or caudal fins. Urolophidae: tail with fan-like caudal fin. Gymnuridae: disc extremely broad (more than 1.5 times as broad as long), tail very short (shorter than 1/2 disc width). Myliobatidae: head projecting from disc; eyes and spiracles laterally on head.

Remarks. Occurring in tropical to temperate marine, estuarine and freshwater areas, usually found in shallow coastal waters. Viviparous; feed mostly on benthic animals.