heterocercal fin

/ˌhɛtəroʊˈsʌrkəl fɪn/

Definitions of heterocercal fin

1. noun

   a tail fin with unequal lobes in which the vertebral column turns upward into the larger lobe as in sharks
   antonyms:

   homocercal fin

   symmetrical tail fin extending beyond the end of the vertebral column as in most bony fishes

   type of:

   caudal fin, tail fin

   the tail of fishes and some other aquatic vertebrates