Thorn catfish

from Wikipedia, the free encyclopedia
Thorn catfish
Black catfish (Oxydoras niger)

Black catfish ( Oxydoras niger )

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

The spiny catfish (Doradidae) are freshwater fish from the rivers and lakes of northern and central South America (up to Buenos Aires ). The main area of ​​distribution is the Amazon basin . The family comprises over 30 genera with around 90 known species. Most species are only a few inches to a foot tall. However, Oxydoras niger can grow to be a meter long.

features

Thorn catfish have a stocky shape, often tadpole-shaped with a broad trunk and a narrow tail stalk. The head is broad and flattened, the skull strongly ossified. The boundaries of the bone plates can also be seen through the skin of living animals. A bone plate of the skull extends on the dorsal side to the first, toothed spine of the dorsal fin. The pectoral fins also have a strong fin spine, which is often toothed or grooved. Along the flanks there is a row of roof-tile-like overlapping, mostly thorny bone plates. In Doraops zuloagai the row of bone plates is only present on the front body. The dorsal fin sits far in front, an adipose fin is usually present, but mostly small, rarely stretched. Bone plates can also be present in between. Thorn catfish have a long pair of barbels on the upper jaw and two significantly shorter ones on the lower jaw.

Way of life

Thorn catfish are usually crepuscular or nocturnal. The day is spent in the ground or hidden between plants, roots and leaves. They can anchor themselves with their strong pectoral fins. Most species are territorial , some also live in groups. Little is known about the reproduction of the thorn catfish. Some species should build nests and possibly take care of the brood.

Sound generation

In English, the Doradidae are also called "talking catfishes" because, like the African Mochokidae , they are able to produce audible sounds. When annoyed, they rub a dorsal bone process of the pectoral fin ray in a joint groove. The sounds arise both when moving the pectoral fin forward and backward. The spreading of the pectoral fin is slower and the sound is accordingly longer than when it is pulled. The pauses between the sounds are equally long. The greatest energy of the sounds is at frequencies between 2 and 4 kHz. The Mochokidae differ from the Doradidae only in the faster movement of the pectoral fins, ie the sounds and the pauses between the sounds are shorter than with the Doradidae.

Systematics

Together with the false thorn catfish (Auchenipteridae) the thorn catfish within the catfish-like (Siluriformes) form the superfamily Doradoidea.

Genera and species

Acanthodoras spinosissimus
Great Britain's catfish ( Agamyxis pectinifrons )
Franciscodoras marmoratus
Anadoras weddellii
Centrochir crocodili

literature

Individual evidence

  1. ↑ Wolfgang Pfeiffer: The sound generation of the Dornwelse (Doradidae) and the Fiederbartwelse (Mochokidae) . ( PDF ) In: Zoomorphology . 54, 1965, pp. 669-679.
  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. ↑ a b c d e Birindelli, JLO: Phylogenetic relationships of the South American Doradoidea (Ostariophysi: Siluriformes). Neotropical Ichthyology, 2014 Sociedade Brasileira de Ictiologia, doi: 10.1590 / 1982-0224-20120027
  4. ↑ Sousa, LM & Birindelli, JLO 2011. Taxonomic Revision of the Genus Scorpiodoras (Siluriformes: Doradidae) with Resurrection of Scorpiodoras calderonensis and Description of a New Species. Copeia. 2011 (1): 121-140.

Web links

Commons : Dornwelse (Doradidae)  - Collection of pictures, videos and audio files