heterocercal

/ˌhɛtəroʊˈsɜːrkəl/
adjective
  1. Describing a fish tail fin where the upper lobe is larger than the lower lobe and the spine extends into the upper lobe.
    • The heterocercal shape of the sturgeon's tail is different from most bony fish.
    • In biology class, we learned that a heterocercal fin is common in primitive fish.
    • Sharks have a heterocercal tail that helps them swim efficiently.
Antonyms
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