Orthochromis
| Orthochromis | ||||||||||||
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Orthochromis polyacanthus |
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| Systematics | ||||||||||||
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| Scientific name of the tribe | ||||||||||||
| Orthochromini | ||||||||||||
| Schwarzer, Misof, Tautz & Schliewen, 2009 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Orthochromis | ||||||||||||
| Greenwood , 1954 |
Orthochromis is a genus from the family of cichlids (Cichlidae). Nine species of the genus occur in the northeastern catchment area of Lake Tanganyika , five more in the catchment area of Lake Mweru , four in the upper and middle Congo Basin and one in the Kunene between Namibia and Angola in southwest Africa.
features
Orthochromis species are relatively small cichlids and grow to be 8 to 12 cm long, while males are slightly larger than females and have slightly larger fins.
Characteristic for the species are the slim body, adapted to a life in strongly flowing waters; likewise the upright but sideways-oriented eyes, which gives the fish a goby-like appearance. Most of the scales are comb scales. Round scales, if present, are only found on the chest and stomach. They are always very small and often embedded deep in the skin. The change from the large scales on the sides of the body to the small ones on the chest and stomach happens seamlessly. In some species, the chest and stomach are also scaly. In the dorsal fin, the number of hard rays is increased. However, this does not lead to a reduction in the number of branched soft rays. The second or the second and third branched fin rays of the pelvic fins are elongated. In the outer row of both jaws there are two-pointed teeth of different sizes. In the corners, the teeth are often single-pointed, but never with a conical or spade-shaped tip as in many larger cichlids of the Haplochromini tribe . In the upper jaw, the other teeth, arranged in two to four inner rows, are three or one pointed. Egg spots, as is typical for haplochromine cichlids, are not present. The swim bladder is reduced.
Way of life
Little is known about the way of life of the Orthochromis species. They are not very fond of swimming and occur mainly in fast-flowing stretches of water. The long intestine suggests that their diet is mainly plant-based. Like the haplochromine cichlids, they are ovophilic mouthbrooders . However, it is not certain whether the female alone takes care of the mouthbrood.
species
Today 19 species belong to the genus Orthochromis . In its current composition, however, this is not monophyletic . In addition to the Orthochromis in the narrower sense of the type Orthochromis malagaraziensis occurring in the catchment areas of Malagarasi , Rugufu and Luiche in Tanzania and Burundi , there are four other clades that are possibly only distantly related to the Orthochromis ie S.
- Group I, Orthochromis from the Malagarasi River system
- Orthochromis kasuluensis De Vos & Seegers, 1998 , in the catchment area of the upper Ruchugu in the Malagarasi river basin
- Orthochromis luichensis De Vos & Seegers, 1998 , endemic in the catchment area of the Luiche in Tanzania
- Orthochromis malagaraziensis (David, 1937) ( type species ), Malagarasi
- Orthochromis mazimeroensis De Vos & Seegers, 1998 , Mazimero and Nanganga in Burundi
- Orthochromis mosoensis De Vos & Seegers, 1998 , endemic to the catchment area of the upper Malagarasi in Burundi
- Orthochromis rubrolabialis De Vos & Seegers, 1998 , endemic to the Majamazi [= Milowesi], a tributary of the Ugalla in Tanzania (catchment area of the Malagarasi)
- Orthochromis rugufuensis De Vos & Seegers, 1998 , endemic to the Rugufu River in western Tanzania (catchment area of Lake Tanganyika )
- Orthochromis uvinzae De Vos & Seegers, 1998 , endemic to the Igamba Falls in Malagarasi
- Group II, Orthochromis from the catchment area of the upper Congo
- Orthochromis polyacanthus ( Boulenger , 1899) in the catchment area of the upper Congo and inLake Mweru
- Orthochromis stormsi (Boulenger, 1902) , Mweru Lake, Upper Congo and its tributaries
- Orthochromis gecki Schedelet al., 2018 , upper Lualaba Schedel et al., 2018
- Orthochromis kimpala Schedel et al., 2018 , upper Lualaba
- Group III, also from the catchment area of the upper Congo, but a different clade than Group II
- Orthochromis torrenticola (Thys van den Audenaerde, 1963)
- Group IV closely with Pseudocrenilabrus related
- Orthochromis kalungwishiensis (Greenwood & Kullander , 1994) , Kalungwishi
- Orthochromis katumbii Schedel et al., 2018 , Bangweulusee and Mwerusee
- Orthochromis luongoensis (Greenwood & Kullander, 1994) , endemic to the Luongo , a tributary of the Luapula in Zambia
- Orthochromis machadoi ( Poll , 1967) , Kunene between Namibia and Angola
- Orthochromis mporokoso Schedel et al., 2018 , Bangweulusee and Mwerusee
- Group V, sister group to Pseudocrenilabrus, Astatoreochromis , Tropheini , Haplochromis and the Haplochromini of Lake Malawi.
- Orthochromis indermauri Schedel et al., 2018 , from the Lufubu, a tributary of Lake Tanganyika
literature
- Anton Lamboj: The cichlids of western Africa. Publisher: Natur und Tier, 2006, ISBN 386-659000-8
Individual evidence
- ↑ a b De Vos, L. & Seegers, L. 1998. Seven new Orthochromis species (Teleostei: Cichlidae) from the Malagarasi, Luiche and Rugufu basins (Lake Tanganyika drainage), with notes on their reproductive biology. Ichthyological Exploration of Freshwaters 9 (4): 371-420.
- ↑ Orthochromis on Fishbase.org (English)
- ↑ Matschiner, M., Musilová, Z., Barth, JMI, Starostová, Z., Salzburger, W., Steel, M. & Bouckaert, R. (2017): Bayesian Phylogenetic Estimation of Clade Ages Supports Trans-Atlantic Dispersal of Cichlid Fishes. Systematic Biology, 66 (1): 3-22. DOI: 10.1093 / sysbio / syw076 . Pages 174 - 176 in the supplement .
- ↑ a b c d e Schedel, FDB, Vreven, EJWMN, Manda, BK, Abwe, Manda, AC & Schliewen, UK (2018): Description of five new rheophilic Orthochromis species (Teleostei: Cichlidae) from the Upper Congo drainage in Zambia and the Democratic Republic of the Congo. Zootaxa, 4464 (3): 301-349, doi: 10.11646 / zootaxa.4464.3.1 .
- ↑ a b Frederic DB Schedel, Zuzana Musilova and Ulrich Kurt Schliewen (2019): East African cichlid lineages (Teleostei: Cichlidae) might be older than their ancient host lakes: new divergence estimates for the east African cichlid radiation. BMC Evolutionary Biology, 19:94. Doi: 10.1186 / s12862-019-1417-0
