The smalleye pygmy shark, Squaliolus aliae, is a very small dogfish (about 22cm) characterized by its small eye, with diameter about 46-70% of interorbital width, and with upper margin angular and chevron-shaped; upper lip with a pair of prominent lateral papillae (rarely indistinct) (Ref. 31367, 6871).Colour: dark brown to black, fin margins pale (Ref. 6871). Squaliolus are the only sharks with a fin spine on its first dorsal fin (spine sometimes concealed by skin) but not on its second dorsal fin; second dorsal fin long-based and low, about twice the length of the first dorsal fin base; first dorsal-fin base closer to pectoral fins than to pelvic fins; and caudal fin nearly symmetrical, with subterminal notch present (Ref. 247, 6871).