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Elasmobranchiate, e-las-mo-brang′ki-āt, adj. pertaining to a class, subclass, or order of fishes including sharks and skates, having lamellar branchi� or plate-like gills.

Respiration is achieved by the passage of water over double gills or branchi�; the water, after it has completed its purpose, being ejected through a moderately long tube, technically called a siphon.

It is said, however, that they frequently lose their gills like the other members of the genus, though some authorities maintain that the true axolotl never loses its gills, and that merely confusion with A. tigrīnum has led to the belief, as this species sometimes retains its branchi�, though usually it loses them.

They have red, rarely yellow or green, blood circulating in a double system of contractile vessels, a double ganglionated nervous cord, and respire by external branchi�, internal vesicles, or by the skin.

Amphib�ia, a class of vertebrate animals, which in their early life breathe by gills or branchi�, and afterwards partly or entirely by lungs.