isocercal

adjective

iso·​cer·​cal

1

: having symmetrical upper and lower lobes and a gradually tapering vertebral column

—used of the tail fin of a fish

2

: having or relating to an isocercal tail fin

isocercy

ˈ⸗⸗ˌsərsē

-rkē

noun

plural -es

Word History

Etymology

is- + -cercal

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