• (a.) Having the tail nearly or quite symmetrical, the vertebral column terminating near its base; -- opposed to heterocercal.
a caudal fin with upper and lower lobes that are nearly equal in size. 
Ho`mo·cer'cal adjective [ Homo- + Greek ... tail.] (Zoology) Having the tail nearly or quite symmetrical, the vertebral column terminating near its base; -- opposed to heterocercal . 
Homocercal is a term applied in the case of fishes which have tails with rays diverging symmetrically from the backbone, as opposed to heterocercal.
(Gk: homos=the same; circa round, all around) a tail fin with equally sized upper and lower lobes
[adj] - (ichthyology) possessing a symmetrical tail that extends beyond the end of the vertebral column (as in most bony fishes)
homocercal A reference to describe a fish that has a tail with two symmetrical lobes that extend beyond the end of the vertebral column, or a tail of this kind.
A caudal fin with equal sized lobes.
adjective possessing a symmetrical tail that extends beyond the end of the vertebral column (as in most bony fishes)
having an equally divided tail, characteristic of adult modern bony fishes. Cf. diphycercal, heterocercal.