Haplochromis thereuterion
Haplochromis thereuterion | ||||||||||||
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Haplochromis thereuterion in an aquarium at the Berlin Aquarium . |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Haplochromis thereuterion | ||||||||||||
van Oijen & Witte , 1996 |
Haplochromis thereuterion is a species of cichlid endemic to Lake Victoria in East Africa. It is only known from rock islands in the northern part of the Mwanza Gulf and from the rocky shores of Butimba Bay and Nyegezi Bay.
features
Haplochromis thereuterion is a small cichlid with a maximum length of 8.2 cm. Its body is elongated and strongly flattened at the sides, the mouth is terminal and pointed, the lips slightly thickened. All scales on the head are cycloid , those on the back are cycloid or weakly ctenoid, those on the flanks and on the caudal peduncle are ctenoid. Males are blue-gray on the top and silvery-white on the underside. Sexually active males become blackish. The dorsal fin is dark below, gray above. The front third of the caudal fin is black, the remaining part grayish, the edges red. The anal fin is blackish, egg spots, if present, are orange-yellow. The pectoral fins are transparent, the pelvic fins black. Females and juveniles have a clear longitudinal ligament on the flanks that extends from the gill cover to the tail stalk. Another band below the dorsal fin is a little less pronounced. The sides of the head are gray, the throat and belly are silvery-white. In young fish, the entire top of the head is gray.
- Fins formula : dorsal XV – XVI / 8–10, anal III / 7–10.
Way of life
Haplochromis thereuterion is relatively rare and lives in the upper water zone of Lake Victoria at depths of 0.5 to 4 meters, on the periphery of rock regions, but never directly between the rocks. It feeds mainly on approach food (insects such as ants and two-winged birds ), insect larvae ( mosquito larvae and caddis-fly larvae ) and copepods are also ingested. Like all Haplochromis species, it is a mouthbrooder .
Danger
The IUCN classifies Haplochromis thereuterion as endangered ("Vulnerable"). After the introduction of the Nile Perch , the population continued to decline. In Mwanza -Golf he disappeared. The possible hybridization with other, closely related species is seen as the greatest threat to the future of the species , since the reduced depth of view of the water due to increasing water pollution makes it difficult to recognize the species and to choose the right sexual partner.
literature
- MJP van Oijen & F. Witte: Taxonomical and ecological description of a species complex of zooplanktivorous and insectivorous cichlids from Lake Victoria. Zool. Verh. Leiden, 1996, ISSN 0024-1652 / ISBN 90-73239-44-3 PDF
Web links
- Haplochromis thereuterion on Fishbase.org (English)
- Haplochromis thereuterion in the endangered Red List species the IUCN 2010. Posted by: Witte, F., de Zeeuw, MP & Brooks, E., 2010. Accessed August 15, 2012th