Labeobarbus microbarbis
| Labeobarbus microbarbis | ||||||||||||
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| Scientific name | ||||||||||||
| Labeobarbus microbarbis | ||||||||||||
| ( Poll & David , 1937) |
Labeobarbus microbarbis ( Syn .: Barbus microbarbis ) is an extinct freshwater fish from the carp family . It was endemic to Lake Luhondo in Rwanda .
features
Labeobarbus microbarbis is only known from the holotype . The specimen has a standard length of 216 mm. The body height is 31 mm, the head length 23.6 mm, the length of the pectoral fin 19.9 mm, the length of the caudal stalk 15.7 mm, the height of the caudal stem 11.1 mm, the length of the snout 3.3 mm, the width of the mouth 7 , 4 mm, the eye diameter 5.5 mm and the interorbital distance (distance between the eyes) 9.2 mm.
The mouth is below. The curved lower jaw does not have a horny edge. The back and front barbels are very short. There is a row of five teeth in the inner pharynx. The contour of the pharynx is gently curved. On the lower branch of the first gill arch there are 15 gill spines .
The scales on the back of the body have parallel welts, on the shoulders they are streaked. There are 32 rows of scales on the lateral line organ , and twelve on the tail stalk. Between the dorsal midline and the lateral line and between the lateral line and the ventral midline there are 5 ½ rows of scales. There are 2 ½ rows of scales between the lateral line and the base of the pectoral fin. The dorsal fin has nine branched and four unbranched rays. The last ray is moderately thickened and ossified into a smooth thorn. The anal fin has three unbranched and five branched rays.
The top of the body is dark gray, the underside lighter gray. The scales have a black border.
status
Labeobarbus microbarbis was declared extinct by the IUCN in 2006. The species had a very restricted range of less than 20 km². The decline of Labeobarbus microbarbis began between 1935 and 1938 when Haplochromis species and young cichlids of the genus Tilapia were released into Lake Luhondo. These multiplied so strongly that by 1952 they had displaced the larger endemic carp fish, including Labeobarbus microbarbis . In addition, many specimens perished as bycatch in the fishing industry.
literature
- Keith Edward Banister: A Revision of the Large African Barbus . In: Bulletin of the British Museum (Natural History) Zoology. Volume 26, The Stonebridge Press, Bristol, 1973-1974. ISSN 0007-1498 . Pp. 87-89
- De Vos, L. and Thys van den Audenaerde, DFE 1990. The effects of Tilapia introductions in Lake Luhondo, Rwanda . Environmental Biology of Fishes 27: p. 203-208