Lampreys are parasitic on other fish, attaching to them with an oral, suckerlike disk. Their streamlines bodies allow easy movement through the dense medium. Tail muscles are organized for powerful force. The swim bladder provides buoyancy. This group includes the sharks, skates, rays, and chimaeras.
Chimaeras are almost scaleless, with a body resembling a rat.
The highly maneuverable fins are supported by rays that originate from the dermis. The teleosts are a very successful group occupying the reef and open ocean habitats. The lobe-finned fishes bear fleshy extensions on the body. Amphibians Origin of Amphibians Arising during the Devonian, the lobed-finned fishes used their lobed fins to move over land from one muddy pool to the next. Lungfishes in Australia live in water and gulps air at the surface until the pool dries up, then it encases itself in mud waiting for the next rainy season.