Haplochromis arcanus
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| Greenwood & Gee , 1969 |
Haplochromis arcanus is a fish of the genus Haplochromis within the cichlid family. The species is on the Red List of Endangered Species of the IUCN with the status DD (Data Deficient / insufficient data). It is / was endemic to Lake Victoria and lived on mud floors at depths of up to 50 meters.
description
Haplochromis arcanus was described by Greenwood & Gee in 1969 and is 14 centimeters long (without the caudal fin). Its specific epithet arcanus comes from the Latin word for secret or mysterious. This refers to the fact that the descriptor could not clearly assign the fish to be related within the school of species of Lake Victoria cichlids. They also had only nine specimens from two sites that were close together. Some of the animals were already gutted or had empty intestines, which is why it is not known what they fed on. Due to the slender, single-pointed outer teeth and the head profile, it can be assumed that they are fish-eaters. For this reason, they have already been assigned to the genus Prognathochromis , which, however, is not sufficiently defined and is therefore not generally accepted at the moment. The live color of the fish is unknown. A single, relatively large egg spot in the anal fin of the males is striking . The snout looks slightly beak-shaped due to a small knob at the front on the underside of the lower jaw and a clearly defined upper jaw process. H. arcanus is similar to other species in the Haplochromis tridens group, especially H. dolichorhynchus and H. tyrianthinus .
Occurrence
So far the species is only known from the Ugandan part of Lake Victoria, south and north of Nsadzi Island. The captured animals lived relatively deep between about 20 and 50 meters above mud floors.
Reproduction
As with all Haplochromis -like, this species should also be a maternal mouthbrooder .
die out
Time and again it is claimed that many of the cichlid species of Lake Victoria are extinct. It is also variously asserted of this species, Haplochromis arcanus . The disappearance of all these species is mainly attributed to the sudden strong increase of the Nile perch, which was released in the lake at the end of the 1950s, which was observed in the early 1980s . However, since this large fish has been intensively fished with industrial means and its population in Lake Victoria has been decimated considerably as a result, many of the smaller species have been able to recover that were previously said to be extinct. Which species in Lake Victoria actually became extinct due to the Nile perch cannot be determined due to the poor data situation in a body of water the size of this lake. It is therefore unknown whether Haplochromis arcanus is still found in Lake Victoria today.
Web links
- Haplochromis arcanus on Fishbase.org (English)
- Haplochromis arcanus inthe IUCN Red List of Threatened Species 2011.1. Posted by: F. Witte, MP de Zeeuw, 2010. Retrieved October 4, 2011.
Individual evidence
- ^ PH Greenwood, JM Gee: A revision of the Lake Victoria Haplochromis species (Pisces, Cichlidae). Part VII. Bulletin of the British Museum (Natural History) Zoology, 18 (1), 1969, pp. 1-65.
- ↑ PH Greenwood: Towards a phyletic classification of the 'genus' Haplochromis (Pisces, Cichlidae) and related taxa. Part II; the species from lakes Victoria, Nabugabo, Edward, George and Kivu. Bulletin of the British Museum (Natural History) Zoology, 39 (1), 1980, pp. 1-101.
- ^ MJP van Oijen: The generic classification of the haplochromine cichlids of Lake Victoria, East Africa . Zoological Negotiations (Leiden) No. 302, 1996, pp. 57-110.
- ↑ F.Witte, BS Msuku, JH Wanink, O. Seehausen, EFB Katunzi, PC Goudswaard, T. Goldschmidt: recovery of cichlid species in Lake Victoria on examination of factors leading to differential extinction . Rev. Fish Biol. Fish., 10, 2000, pp. 233-241.