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tail of a leopard shark
Triakis semifasciata


Relating to, having, or being a tail fin in which the upper lobe is larger than the lower and the vertebral column extends into the upper lobe, as in sharks.

[hetero- + Greek kerkos, tail + -al.]


(Zoology) ichthyol of or possessing a tail in which the vertebral column turns upwards and extends into the upper, usually larger, lobe, as in sharks. Compare homocercal
[C19: from hetero- + Greek kerkos tail]


(ˌhɛt ər əˈsɜr kəl)

designating or having a tail fin in which the upper lobe is larger than the lower lobe, as in sharks.
[1830–40; hetero- + Greek kérk(os) tail + -al1]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.heterocercal - possessing a tail with the upper lobe larger than the lower and with the vertebral column prolonged into the upper lobe
ichthyology - the branch of zoology that studies fishes
homocercal - possessing a symmetrical tail that extends beyond the end of the vertebral column (as in most bony fishes)
References in periodicals archive ?
Its external morphology, heterocercal fins, type of scale and its highly vascularized swim bladder, place it as a primitive fish (Paramo, 1982).
It shows an elongated fish-like creature with a mouthful of large triangular teeth, with the right number of fins for a shark, a heterocercal tail, and a human foot protruding from its mouth.
Therefore, the specimens above briefly described are tentatively attributed to the order 'Perleidiformes' (sensu Berg, 1937) based on the following characters: body outline fusiform; gape commonly moderate; snout with nasals searated by a large (post)rostral; almost vertical preopercular with an expanded dorsal region; scales deeper than long in the anterior portion of the flank, with the posterior borders often denticulated; rays of dorsal and anal equal in number to radials; caudal fin heterocercal with several epaxial rays.