Oreochromis karongae
| Oreochromis karongae | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Oreochromis karongae |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Oreochromis karongae | ||||||||||||
| ( Trewavas , 1941) |
Oreochromis karongae is a species of fish from the family of cichlids (Cichlidae), which occurs in the East African Lake Malawi and its surroundings, including Lake Malombesee and the Ikapu and Itamba crater lakes.
features
Oreochromis karongae is a large species of cichlid and reaches a maximum standard length of 42 cm. The head length is 31 to 36% of the standard length. The head is broad and rounded; the jaws are short and covered with numerous teeth, which are arranged in four to six broad bands. Males are black, the dorsal and caudal fins have white borders. Their genital appendages are pink or light yellow and can be long. Females and fry are gray with four to six vertical stripes on the sides of the body. They cannot be distinguished with certainty from the females and fry of Oreochromis squamipinnis . The females and juvenile fish from the Ikapu crater lake are bright golden yellow.
- Fins formula : dorsal XV – XVII / 10–12, anal III / 8–10.
Way of life
Oreochromis karongae occurs in all areas of the lake and has been observed in bays overgrown with plants, in pure rock regions, over sandy areas and in transitional biotopes. Usually the species stays in shallow water, no deeper than ten meters. The maximum depth in which Oreochromis karongae was still observed is 40 to 50 meters. The fish feed mainly on phytoplankton and occasionally take up sediment and sand from the lake floor. A morph with a particularly large number of teeth may also eat vegetation on the rocks. Diatoms are the most important part of the diet.
Like all Oreochromis TYPES is Oreochromis karongae a mouthbrooders , wherein the female takes care of the brood, while the male defends the station. The areas established for reproduction are located in water depths of up to a maximum of 28 meters. To lay their eggs, the males build pits in the sand, which can sometimes take the form of large craters measuring up to 1.9 meters in diameter. The size of the spawning pits is related to the size of the males. Spawning usually takes place in the early morning hours. Then the female takes the fertilized eggs in her mouth and carries them around with her. The juvenile fish are protected in their mouths until they have reached a size of around 24 mm.
Oreochromis karongae is heavily fished and the IUCN has assessed the stock as critically endangered.
Systematics
The species was scientifically described for the first time in 1941 by the British ichthyologist zoologist Ethelwynn Trewavas and then assigned to the genus Tilapia . Today it belongs to Oreochromis and there to the so-called "flagellum tilapia " (sub-genus Nyasalapia ), the males of which have specially shaped appendages on the genital papilla . The trait may have developed independently of each other several times and the subgenus Nyasalapia would then not be monophyletic . Oreochromis saka , described by RH Lowe in 1953, may be just a geographic morph or synonym of O. karongae .
supporting documents
- ↑ a b c d e Oreochromis karongae on Fishbase.org (English)
- ↑ Ethelwynn Trewavas (1983). Tilapiine fishes of the genera Sarotherodon , Oreochromis , and Danakilia /. London: British Museum (Natural History). doi: 10.5962 / bhl.title.123198 , page 465.
- ↑ Oreochromis karongae in the Red List of Threatened Species of the IUCN 2018. Posted by: Kanyerere, GZ, Phiri, TB & Shechonge, A., 2018. Accessed August 15 of 2019.
- ↑ Oreochromis karongae in the Catalog of Fishes (English)
- ↑ a b Ford, AGP, Bullen, TR, Pang, L., Genner, MJ, Bills, R., Flouri, T., Ngatunga, BP, Rüber, L., Schliewen, UK, Seehausen, O., Shechonge, A., Stiassny, MLJ, Turner, GF & Day, JJ (2019): Molecular phylogeny of Oreochromis (Cichlidae: Oreochromini) reveals mito-nuclear discordance and multiple colonization of adverse aquatic environments . Molecular Phylogenetics and Evolution, April 2019, doi: 10.1016 / j.ympev.2019.04.008
- ↑ Oreochromis saka in the Catalog of Fishes (English)