Mobulidae
by J. D. McEachran and C. Capape
Very large rays (disc width to 9.1 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, tapering to a filament, with or without one or several serrated spines on top near base. Mouth terminal or slightly underneath; teeth in one or both jaws, minute, in many series forming a band; inner surface of gill-slits surrounded by a series of lamellae (gill-plates). Dorsal fin small, in front of spine; pectoral fins reaching forward, each forming a distinct but separate vertical lobe in front of head ('horns'), the finrays not continued below eyes; no caudal fin. Upper surfaces naked or covered with thornlets.
Semipelagic to pelagic in tropical and warm temperate seas, over continental shelves and also near oceanic islands; many of the species apparently make long migrations; gregarious, usually swimming in pairs near the surface by vertical undulations of the pectoral fins, also basking at the surface or occasionally resting at the bottom; common in the tropical eastern Atlantic, frequently caught by harpoons, long-lines and in offshore trawls and of some fishery importance. Feeding on small pelagic fishes and crustaceans, filtered out by the gill-plates. Ovoviviparous; females contain 1-2 embryos.
Genera 2 (4 by some authors); in Clofnam area 1.
Recent revisions: on a regional basis only by Whitley (1936), Fowler (1941), Bigelow and Schroeder (1953), Cadenat (1960).