Archocentrus centrarchus
| Archocentrus centrarchus | ||||||||||||
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Archocentrus centrarchus |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Archocentrus | ||||||||||||
| Gill in Gill & Bransford , 1877 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Archocentrus centrarchus | ||||||||||||
| (Gill, 1877) |
Archocentrus centrarchus is a freshwater fish from the family of cichlids , which in Central America in the basins of the San Juan River , in Managua- and Nicaragua and other rivers discharging into the Caribbean, occurs.
features
Males of Archocentrus centrarchus become over 15 cm long, females remain slightly smaller. The fish are high-backed and have a yellowish olive to yellowish green basic color, with the lower half of the body shimmering bluish. The belly and throat are yellow. There are seven dark transverse ligaments on the sides of the body, which can be interrupted and sometimes extend to the dorsal and anal fin. There are two dark spots on the gill cover.
Archocentrus is similar to its sister genus Amphilophus but has a more rounded shape, remains smaller (<150 mm SL vs. 200 to 300 mm SL), has only 13 trunk vertebrae (vs. 14), an increased number of anal fin pterygiophores from the first hemalia (4 vs. .> 2) and thus a proportionally increased number of fin spines in the anal fin (usually 10 vs. 7 in Amphilophus ), an increased number of fin spines in the dorsal fin. Archocentrus differs from Cryptoheros and Amatitlania by the lack of sexual dimorphism in terms of size and color and the more pointed snout. The body is flattened laterally and resembles some South American heronine cichlids, especially the Heros genus . The teeth are conical and pointed and on the premaxillary and in the first row in the lower jaw without a second point. On the first gill arch there are 12 to 17 (mostly 14) long, slender gill rakes.
- Fins formula : dorsal XV – XVII / 7–9, anal IX – XI / 7–9.
Way of life
Archocentrus centrarchus occurs in swamps and stagnant or slowly flowing waters at heights of less than 50 meters above sea level and prefers flat and warm areas in these waters. The habitat has a soft ground (mud, fallen leaves), is characterized by dead wood, dense aquatic vegetation, floating plants ( water hyacinths ), is relatively low in oxygen and has a temperature of 26 to 36 ° C. In Lake Nicaragua, the species occurs almost exclusively in large populations of chandelier algae ( Chara ). Archocentrus centrarchus feeds on algae, detritus , aquatic insects and their larvae.
Reproduction
Females willing to spawn have a black lower half of their body. The males court their fins, flap their tails and shake with their heads down in front of the females. Archocentrus centrarchus always spawns open, often on vertical surfaces or under overhanging wood, but never in caves. With an average diameter of less than a millimeter, the eggs are extremely small, but the clutch of small, only 5 to 7 cm long females with 300 to 600 eggs is relatively large. The eggs are looked after by the female, while the male only guards the territory and growls away invading fish. The growling noises consist of short impulses lasting 0.5 to 4 seconds with frequencies of 100 to 1300 hearts. The fry hatch after 3 days at a temperature of 27 ° C. The parents put them in a previously dug pit below the spawning substrate and, after swimming free, both parents guide them.
Systematics
The species was described in 1877 by the American ichthyologist Theodore Nicholas Gill under the scientific name Heros centrarchus , Archocentrus in the same work as a subgenus of Heros . Terra typica is Lake Nicaragua. The species epithet centrarchus is intended to indicate the outward similarity of the species with the North American sunfish (Centrarchidae). The subgenus Archocentrus was later raised to generic rank and you have been assigned to other species over time, including the convict cichlid , the lemon cichlid , the Sajica cichlid , the yellow-headed cichlid , the Panama tilapia and Schwarzgebänderte cichlid . Today the genus is monotypical after a revision of the Central American heronia cichlids .
literature
- Rainer Stawikowski and Uwe Werner: America's cichlids. Volume 1, Verlag Eugen Ulmer, 1998, ISBN 978-3-8001-7270-2 .
Individual evidence
- ↑ a b c Archocentrus centrarchus on Fishbase.org (English)
- ↑ a b Stawikowski and Uwe Werner (1998), p. 438.
- ↑ a b O. Říčan, L. Piálek, K. Dragová, J. Novák: Diversity and evolution of the Middle American cichlid fishes (Teleostei: Cichlidae) with revised classification. In: Vertebrate Zoology. 66 (1), 2016, pp. 1–102 ( PDF ).
- ↑ Stawikowski and Uwe Werner (1998), pp. 438-440.
- ^ TN Gill, JF Bransford: Synopsis of the fishes of Lake Nicaragua. Proceedings of the Academy of Natural Sciences of Philadelphia v. 29, 1877, pp. 175-191.
- ↑ Stawikowski and Uwe Werner (1998), page 437.
Web links
- Archocentrus centrarchus on Fishbase.org (English)