Harlequin rasbora of a harlequin. The harlequin rasbora is a fish that has an approximately lozenge-shaped body, whose basal colour from the head to the caudal peduncle is an orange-pink, the exact hue varying depending upon such factors as water conditions and the original population from which the fish was obtained. The posterior half of the body is overlaid with a large, roughly triangular black marking, that tapers toward the terminal end of the caudal peduncle, and begins approximately below the midpoint of the attachment of the dorsal fin (commonly called a "black wedge"). In common with all cyprinids, the articulation of
Whitefin dogfish is distinctive in being the only "Centroscyllium" species with abrupt black markings beneath its head, trunk, and pectoral fins, with a black stripe running from under the caudal peduncle to over the pelvic fins. These markings are in fact concentrations of tiny light-emitting photophores. Unusually, this shark also has photophores along the undersides of its upper eyelids. What function these structures could serve is unclear; Tchernavin speculated that they could be used to illuminate prey or stimulate the eye. The rest of the body is gray-brown, with white fin margins. There are numerous small cone-shaped, hooked prickles over the body,