Grasseichthys gabonensis
| Grasseichthys gabonensis | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Grasseichthys | ||||||||||||
| Géry , 1964 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Grasseichthys gabonensis | ||||||||||||
| Géry, 1964 |
Grasseichthys gabonensis is a very small freshwater fish that occurs in Gabon in various places in the Ogowe and Ivindo basins.
features
The fish is only 2.1 cm long and has a slender, laterally flattened body and a small head with a terminal mouth and large eyes. The height of the females is 17.9 to 20% of the standard length , of the males 18.0 to 22.7%. The head reaches 18.0 to 22.7% of the standard length, the distance between the eyes 11.9 to 12.9% of the head length. Grasseichthys gabonensis is scaly and almost transparent. Only a few scattered melanophores , especially on the back and abdomen and along a center line on the body flanks, pattern the body. A diamond-shaped, dark spot lies on the caudal fin root. The fin rays are also dark.
Teeth are missing. The gill space is protected below by two Branchiostegal rays . The gill openings are small and are located above the base of the pectoral fin. The pectoral fins are far below. The caudal fin stalk is long and has a keel made of transparent fabric at the top and bottom, which apparently arose from the caudal fin membrane that was extended to the front. The ventral keel is more developed, the caudal fin is forked. Of the 16 rays of the caudal fin, one is unbranched on the dorsal and abdominal side, the others are branched. A lateral line organ is missing, the epibranchial organ is reduced or completely absent according to various sources.
- Fin formula : dorsal fin iii / 4–5; Anal fin iii / 6–7.
Systematics
Grasseichthys gabonensis is part of the Kneriidae family and is considered a pedomorphic Kneriide because of its larvae-like appearance . The Grasseichthys population in the central Congo Basin forms another, previously undescribed Grasseichthys species.
Danger
The population in Ivindo is at risk from pollution caused by mining.
literature
- Melanie Stiassny, Guy Teugels & Carl D. Hopkins: The Fresh and Brackish Water Fishes of Lower Guinea, West-Central Africa, Volume 1. ISBN 9789074752206
Web links
- Grasseichthys gabonensis on Fishbase.org (English)
- Grasseichthys gabonensis in the endangered Red List species the IUCN 2010. Posted by: Moelants, T., Snoeks, J., Laleye, P. & Contreras-MacBeath, T., 2010. Accessed December 1, 2011th