Whale catfish

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Whale catfish
Cetopsis plumbea

Cetopsis plumbea

Systematics
Overcohort : Clupeocephala
Cohort : Otomorpha
Sub-cohort : Ostariophysi
Otophysa
Order : Catfish (Siluriformes)
Family : Whale catfish
Scientific name
Cetopsidae
Bleeker , 1858

The whale catfish ( Cetopsidae) are a family from the order of the catfish-like (Siluriformes). They are South American freshwater fish .

description

Whale catfish are small fish with a maximum body length of 26 centimeters. They are scaly and without bone plates under the skin with an almost cylindrical, streamlined body and blunt snout. There are three pairs of barbels , the nasal pair is missing. The anal fin has a long base and usually 20 to 49 soft rays. Dorsal and pectoral fins usually have no hard rays. There are two subfamilies:

  • As adults, the Cetopsinae have no adipose fin , but there is a small one in young animals. The swim bladder is reduced and surrounded by a bone capsule. The dorsal fin is always located far in front of the body and can have a weak hard ray. The anal fin is of medium length. The eyes are very small.
  • The Helogeninae with Helogenes as the only genus are no more than seven centimeters long. They have a dorsal fin roughly in the middle of the body with five soft rays, which, like the pectoral fins, never have a hard ray. A small adipose fin may be present. The anal fin is long with 32 to 49 soft rays.

Systematics

In the classical system, the whale catfish are the only family of the superfamily Cetopsidea and together with the Hypsidoridae and the remaining catfish apart from the primitive catfish (Diplomystidae) form a trichotomy . Molecular biological studies, however, indicate a position within the subordination of the Siluroidei.

The family is currently assigned 5 genera with a total of 43 species distributed over 2 subfamilies. (As of June 2018)

Subfamily Cetopsinae

Subfamily Helogeninae

Web links

Commons : Whale Catfish (Cetopsidae)  - Collection of pictures, videos and audio files

literature

Individual evidence

  1. ^ Joseph S. Nelson: Fishes of the world . 4th edition. John Wiley & Sons, Hoboken 2006, ISBN 978-0-471-25031-9 , pp. 164 .
  2. JP Sullivan, Lundberg JG; Hardman M: A phylogenetic analysis of the major groups of catfishes (Teleostei: Siluriformes) using rag1 and rag2 nuclear gene sequences . In: Mol Phylogenet Evol. . 41, No. 3, 2006, pp. 636-62. doi : 10.1016 / j.ympev.2006.05.044 .
  3. Whale catfish on Fishbase.org (English)