Myliobatidae
by J. D. McEachran and C. Capape
Medium to large rays (disc width to 2.5 m), the disc lozenge-shaped, much wider than long; head elevated from disc, with eyes and spiracles on side; tail distinct from disc, much longer than disc length, becoming slender and whip-like, with one or several serrated spines on top near base. Mouth underneath, with several papillae on floor; teeth fused into grinding plates in 1-7 series forming a tesselate pattern. Spiracles well developed. Dorsal fin small, in front of spine; pectoral fins meeting below tip of snout to form a lobe, the finrays not always continued in area below eye; no caudal fin. Upper surfaces naked or with tubercles down midline of disc.
Semipelagic in tropical to warm temperate coastal waters, occasionally oceanic; fairly abundant in shallow tropical waters, often seen swimming at surface by undulations of entire pectoral fins; occasionally marketed in the tropics, destructive to commercial oyster and clam beds. Feeding on bottom-living crustaceans and molluscs. Ovoviviparous; females contain 2-10 embryos, with a gestation period of up to one year.
Genera 4; in Clofnam area 2.
Recent revisions: on a regional basis only, Fowler (1941), Bigelow and Schroeder (1953), Wallace (1967).