Definition that contains tail fin
- squid widely distributed fast-moving ten-armed cephalopod mollusk having a long tapered body with triangular tail fins
- yellowtail game fish of southern California and Mexico having a yellow tail fin
- seriola dorsalis game fish of southern California and Mexico having a yellow tail fin
- heterocercal fin a tail fin with unequal lobes in which the vertebral column turns upward into the larger lobe as in sharks
- ichthyosaur any of several marine reptiles of the Mesozoic having a body like a porpoise with dorsal and tail fins and paddle-shaped limbs
- homocercal fin symmetrical tail fin extending beyond the end of the vertebral column as in most bony fishes