Black calloused catfish
| Black calloused catfish | ||||||||||||
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Black callused catfish ( Hoplosternum littorale ) |
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| Scientific name | ||||||||||||
| Hoplosternum littorale | ||||||||||||
| ( Hancock , 1828) |
The black callus catfish ( Hoplosternum littorale ) is a freshwater fish species from the armored and callous catfish family (Callichthyidae), which occurs east of the Andes in northern and central South America to the Río de la Plata in the south and on the island of Trinidad .
features
Black callous catfish reach a maximum length of 24 cm and have a higher back body than Callichthys callichthys . There are two pairs of relatively long barbels on the upper jaw . Above the midline of the body there are 25 bone plates, below it is 23. The outer rays of the caudal fin are thickened. Different color morphs occur within their large distribution area. In general, the fish are uniformly blue-black. However, there are also black calloused catfish with blackish, blue-gray, dark-gray or greenish coloring on the upper side, slightly lighter body sides and a light, dirty-white belly side and blue-black, light-gray or colorlessly transparent fins. There are no drawings, patterns or stains, and the fins are unspotted. In the males, which is Geschlechtspapille clearly visible.
- Fin formula : dorsal 1/8, anal / 5, pectoral 1 / 8–9, ventral / 6.
Way of life
Black callous catfish live in swamps and weedy waters. During the rainy season, their diet consists mainly of mosquito larvae and detritus , whereas in the dry season they eat various insects, small crustaceans, aquatic two-winged larvae and detritus. In addition, large amounts of anaerobic bacteria are taken up by the substrate.
Like all callous catfish, the male of Hoplosternum littorale , supported by the female, builds a foam nest for reproduction . The breeding season begins with the rainy season. 5,000 to 20,000 eggs with a diameter of 1.8 mm are laid in the nest. The eggs are fertilized by sperm that the female has previously collected in the mouth. The foam nest is guarded by the very aggressive male during this time. Black callous catfish breed for the first time at one year of age.
literature
- Hans-Jochim Franke: Handbook of Welskunde. Urania-Verlag, 1985.
- Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .
Web links
- Black callused catfish on Fishbase.org (English)