Sharks and Rays - (sn Elasmobranchii)

Elasmobranchii is one of the two subclasses of cartilaginous fishes in the class Chondrichthyes, the other being Holocephali (chimaeras). For features that distinguish Elasmobranchii from Holocephali, see those articles. This classification includes great white sharks and the extinct megalodon.

Members of the elasmobranchii subclass have no swim bladders, five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins, and small placoid scales. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The inner margin of each pelvic fin in the male fish is grooved to constitute a clasper for the transmission of sperm. These fishes are widely distributed in tropical and temperate waters.