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
Blob sculpin flap that covers the gills), the branchiostegal membranes are fused to the isthmus (the fleshy projection separating the gill openings), and there are many small cirri (fleshy threads) scattered over the head and body. The operculum is poorly ossified and is covered by a gelatinous layer. Behind the head, the body tapers rapidly to the caudal peduncle and there is a gelatinous layer between the skin and the muscle. The dorsal fin has eight spines and nineteen to twenty soft rays, and the anal fin has no spines and twelve to fourteen soft rays. The pectoral fins are broad and