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
Operculum (gastropod) pentagram-shaped, and is used to dig into the sand to enable the conch to perform a leaping type of locomotion. The structure of the operculum can be described as follows: In 1998 Checa and Jimeneze proposed three types of opercula: There are two basic types of opercula in terms of their material composition: The different shapes of opercula can include ungulate (hooflike), claw-like, or ovate. The type and shape of the operculum is used to help identify and classify related groups (genera) of land operculates, and likewise some marine operculates. The oldest known human depiction of an operculum together with