homocercal

adjective

ho·​mo·​cer·​cal ˌhō-mə-ˈsər-kəl 

ˌhä-

1

of a fish tail fin : having the upper and lower lobes approximately symmetrical and the vertebral column ending at or near the middle of the base

2

: having or relating to a homocercal tail fin

Word History

First Known Use

1838, in the meaning defined at sense 1