Chimaeriformes


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Chimaeriformes

[kī·mir·ə′fȯr‚mēz]
(vertebrate zoology)
The single order of the chondrichthyan subclass Holocephali comprising the ratfishes, marine bottom-feeders of the Atlantic and Pacific oceans.

Chimaeriformes

 

an order of fish of the subclass Holocephali. The order comprises 13 families, of which only three are living: Chimaeridae, Rhynochimaeridae, and Callorhynchidae. Representatives of the first two families are distributed mainly in the depths of the Atlantic, Indian, and Pacific oceans, while those of the third family are distributed only in the seas of the southern hemisphere.

The rabbitfish (Chimaera monstrosa), which belongs to the family Chimaeridae, is occasionally found in the southwestern part of the Barents Sea in the USSR. It is up to 1.5 m long.

The Chimaeriformes have a laterally compressed, scaleless body that gradually tapers into a whiplike tail. The head is blunt and conical; males have a clublike, thorny appendage on the head that serves to clasp the female during mating. The ventral fins have copulatory organs—claspers. The Chimaeriformes feed mainly on benthic invertebrates and on other fish. Fertilization is internal. About 100 eggs mature in each female ovary, but only two are deposited simultaneously, each enclosed in a horny capsule measuring 15–18 cm in length. The Chimaeriformes are virtually of no commercial importance.

REFERENCE

Zhizn’ zhivotnykh, vol. 4, part 1. Moscow, 1971.

G. U. LINDBERG