tail long (? disc), a row soft tubercles along side, with spine
Mobula japanica (Müller & Henle, 1841)
Spinetail mobula, Spinetail devil ray
Disc strongly rhomboidal, much wider than long; wings strongly pointed; head wide, projecting from disc; pectoral fins extend along head and form two large soft horns; front margin of pectoral fin ends under spiracle; a short keel present over the spiracle; eyes and spiracles on side of head; mouth ventral; teeth on both jaws; length of tooth bands ~ 75% of mouth width; teeth long, twice as long as wide, scattered; filter plates of gills with 18-25 side lobes, last lobe leaf shaped, plates separate at tips; tail with small dorsal fin at base long, slender, as long as or longer than disc width, its base oval, with 1 large serrated spine, plus a row of soft tubercles along each side; denticles on upper surface of body dense.
Upper surface dark blue to black; dark inside mouth; lower surface white; dorsal fin black with white tip; tubercles on sides of tail white.
Size: 310 cm wide.
Habitat: pelagic in coastal and oceanic waters.
Depth: to 30 m.
Circumtropical; southern California to Peru (except the Gulf of California)