Meaning of homocercal in English:

homocercal

Pronunciation /ˌhɒmə(ʊ)ˈsəːk(ə)l/ /ˌhəʊmə(ʊ)ˈsəːk(ə)l/

adjective

Zoology
  • (of a fish's tail) appearing outwardly symmetrical but with the backbone passing into the upper lobe, as in all higher fish.

    Contrasted with diphycercal, heterocercal

    ‘The current literature contains several hypotheses about the function of caudal fins of different shapes, and much of this discussion has focused on the difference between heterocercal and homocercal tails.’
    • ‘Both mammals and reptiles returning to the sea developed quite workable homocercal tails in very short order.’
    • ‘This caudal fin structure contrasts with the externally symmetrical homocercal morphology present in most teleost fishes such as bluegill sunfish.’
    • ‘The tail fin of most ray-finned fish, with the exception of sturgeons and paddlefish, is homocercal, nearly symmetrical about the midline.’
    • ‘Generally, osteolepiforms have homocercal, or even trilobate, tail fins.’

Origin

Mid 19th century from homo-‘same’ + Greek kerkos ‘tail’ + -al.