Armored and calloused catfish
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| Bonaparte , 1838 |
The armored and callous catfish ( Callichthyidae from Greek kallis "beautiful", ichthys "fish") are a family from the order of the catfish-like (Siluriformes). With the exception of the south and the areas west of the Andes, the members of this species-rich family live in almost all of South America and are primarily known as freshwater ornamental fish . While calluses mostly live as solitary animals and grow to be 7 to 24 cm tall, the armored catfish are mostly schooling fish, most of which are only 2 to 8 cm tall.
distribution
Armored catfish and callous catfish live in fresh waters in most of South America, in the Amazon basin , in the Orinoco basin , in the Rio São Francisco , in the rivers of Atlantic Brazil, in the basin of Río Paraná and Río Paraguay , in the Río Magdalena , in some rivers in Panama and Brazil in Trinidad . Their biodiversity is highest in the upper Amazon region and in the rivers of the Guayana shield . Apart from Callichthys fabricioi from the Colombian Río Cauca , armored and callous catfish are only found east of the Andes.
features
The body of armored catfish and callous catfish is almost completely armored between the head and caudal fin by two long rows of smooth, roof-tile-like bone plates on the back and sides of the body. The sideline is reduced to a residue on one to six of these bone platelets. The two-chamber swim bladder is surrounded by a bone capsule. The first pectoral and dorsal fin rays are strong, prickly and lockable. The large dorsal fin also has seven to eight soft rays. The anal fin is short. The pelvic fins usually begin below the last third of the dorsal fin. An adipose fin is present. In front of her are some small, unpaired bone platelets, the last of which is formed as a thorn. The eyes are mobile. The little mouth is surrounded by one or two pairs of barbels. There may be additional, shorter protrusions on the upper and lower lip. The jaws are toothless or toothless, the premaxillary is always toothless.
Way of life
Armored catfish and calluses inhabit all types of fresh water, both oxygen-rich, fast-flowing mountain streams and large rivers, flooded areas, and low-oxygen swamps and stagnant waters. They are predominantly crepuscular and feed on larger unicellular organisms ( protists ), very small multicellular animals ( tardigrades , rotifers ), worms and other bottom-dwelling invertebrates, but above all on aquatic insects and small crustaceans . The food is tracked down with the barbels. The head can be pushed into the ground up to the eyes while searching for food. Before the spawning season, some species do not consume any food apart from detritus and plant debris. While the related armor catfish and loach catfish only breathe air in low-oxygen living waters, all armored catfish and callous catfish, regardless of whether their living waters are oxygen-rich or low-oxygen, take in atmospheric air at regular intervals through their mouths. The fish swim quickly to the surface of the water, gasp for air and dive back to the bottom of the water just as quickly. The oxygen is then taken in through the midgut and stale air is expelled through the anus. The midgut is supplied with blood intensively and has reduced smooth muscles. In the armored catfish and callous catfish, the intake of air is especially important for the hydrostatic balance , and additional breathing is only necessary under low-oxygen conditions. During the dry season, they gather in huge groups in residual water and can then tolerate larger salt concentrations. The species from the genera Callichthys and Hoplosternum can, with the help of their pectoral fin spines and meandering movements, leave drying waters and seek new living waters. To avoid dehydration, they usually only do this at night. The bone armor also protects them.
The genera Aspidoras , Scleromystax , Corydoras and Brochis (subfamily Corydoradinae) are substrate spawners , like most other catfish, and attach their spawn to stones, leaves or aquatic plants, while Callichthys , Megalechis , Lepthoplosternum , Hoplosternum and Dianema (subfamily Callichtnestinae) form a swimming pool Build foam and plant material and lay their eggs in them. The foam nest has an advantage in low-oxygen waters because the oxygen content around the eggs is always relatively high here. The foam probably also has an antibacterial effect.
External system
Armored catfish and calluses belong to the suborder Loricarioidei (Sullivan et al., 2006) and superfamily Loricarioidea (Nelson, 2006). They are the sister group of a common taxon of armor , climbing, and spiny dwarf catfish .
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Internal system
The family includes around 200 species in nine genera and two subfamilies. More than 150 species belong to the collective genus Corydoras , the most species-rich genus of the catfish (Siluriformes).
Subfamily armored catfish
The species from the subfamily of armored catfish (Corydoradinae) (Hoedeman 1952) are three to twelve centimeters long. They are high back and flattened on the sides. Their muzzle is round or laterally flattened and more or less long, some with an indented saddle snout. The barbels are short. Armored catfish are schooling fish and substrate spawners. Of the four genera of armored catfish, the large collective genus Corydoras , which cannot be diagnosed by synapomorphism , is considered to be paraphyletic , as the genera Aspidoras and Scleromystax separate them into at least two lineages. In future revisions it is to be expected that Corydoras will be split into several genera.
Subfamily callous catfish
The species from the subfamily of the callous catfish (Callichthyinae) (Hoedeman 1952) are elongated, spindle-shaped or cylindrical. The muzzle is flattened, the mouth small and underneath. The maxillary barbels are long. They build a foam nest and make up less than 10% of the Callichthyidae species. Some callus catfish species can make sounds.
The following cladogram shows the subfamilies, all genera and the probable relationships to each other:
| Callichthyidae |
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Tribal history
The oldest fossil record of a Callichthyiden is Corydoras revelatus from the late Paleocene (58.5–58.2 mya ) of Argentina (Maize Gordo Formation ).
use
Many armored catfish, especially from the species-rich genus Corydoras , are popular aquarium fish, are caught and exported worldwide, and many can also be bred. Larger callus catfish are used for human consumption and are fished and mostly cooked in the shell.
literature
- Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .
- Kurt Fiedler: Textbook of Special Zoology, Volume II, Part 2: Fish . Gustav Fischer Verlag Jena, 1991, ISBN 3-334-00339-6 .
- Joseph S. Nelson : Fishes of the World . John Wiley & Sons, 2006, ISBN 0-471-25031-7 .
further reading
- Erika Matschke, Karl H. Matschke: Armored catfish and calluses . Urania-Verlag, Freiburg 1991, ISBN 978-3-3320-0470-0
- Hans-Georg Evers : Armored catfish. Aspidoras, Brochis, Corydoras . Ulmer Verlag, Stuttgart 1994, ISBN 978-3-8001-7286-3
- Jürgen Schmidt: Corydoras armored catfish . Bede Verlag, Ruhmannsfelden 1997, ISBN 978-3-9317-9226-8
- Frank Schäfer: Armored catfish . Aqualog Animalbook, Rodgau 2003, ISBN 978-3-9360-2724-2
- Frank Schäfer, Hans-Georg Evers: Corydoras. All C numbers . Aqualog Animalbook, Rodgau 2004, ISBN 978-3-9360-2741-9
Individual evidence
- ↑ Hoplosternum littorale on Fishbase.org (English)
- ↑ Callichthys fabricioi on Fishbase.org (English)
- ↑ 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 .
- ↑ Markos A. Alexandrou, Claudio Oliveira, Marjorie Maillard, Rona AR McGill, Jason Newton, Simon Creer & Martin I. Taylor: Competition and phylogeny determine community structure in Müllerian co-mimics. Nature 469, 84–88 (January 2011), doi : 10.1038 / nature09660 Supplementary Information (5.9M) (PDF; 6.2 MB)
- ↑ Ingo Seidel: New findings about the relationships among armored catfish in Aquaristik Fachmagazin No. 223 February / March 2012, Tetra-Verlag GmbH, ISSN 1437-4854
- ↑ Lundberg et al. (2007): Discovery of African roots for the Mesoamerican Chiapas catfish, Lacantunia enigmatica, requires an ancient intercontinental passage . In: Roots of Mesoamerican Catfish. Proceedings of the Academy of Natural Sciences of Philadelphia. ISSN 0097-3157 . 156: 39-53 June 2007
- ^ KA Frickhinger: Fossil Atlas Fish , Mergus-Verlag, Melle, 1999, ISBN 3-88244-018-X
Web links
- Callichthyidae on Fishbase.org (English)
- Callichthyidae database with extensive image material
- Roberto E. Reis: Callichthyidae The Tree of Life Web Project