Dark-bellied snakehead fish
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Dark-bellied snakehead fish ( Parachanna obscura ) |
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| Parachanna obscura | ||||||||||||
| ( Günther , 1861) |
The dark-bellied snakehead fish ( Parachanna obscura ) is a freshwater fish from the snakehead fish family that is widespread in Africa. The distribution area extends from Senegal over the catchment area of Volta and Niger over the river basin of the Shari to the Nile and south to the Congo basin . It also includes numerous coastal rivers in West Africa and Lower Guinea . In the coastal region of Lower Guinea in some regions of the Congo Basin, the species lives sympatric with Parachanna insignis .
features
The dark-bellied snakehead fish reaches a maximum length of 50 cm and has the elongated body that is typical of snakehead fish, tapering slightly towards the rear, with long dorsal and anal fin. The head is flattened and covered with relatively large scales (larger than the body scales). The predatory fish's lower jaw protrudes slightly and is equipped with four to six well-developed fangs. The dorsal and anal fins have no contact with the rounded caudal fin. In most cases the sideline is continuous, sometimes interrupted.
- Fin formula : dorsal 39–45, anal 26–32.
- Lateral row scales 65–78, cross row scales 19–24.
The fish are olive-colored to blackish and show five to eight polygon-shaped or more or less rounded dark spots on the sides of the body . The belly is ocher. There is a dark stripe between the rear edge of the eye and the rear edge of the gill cover. Young fish as long as a finger are ocher-colored and have a dark band on the sides of the body that extends from the tip of the snout to the rear edge of the caudal fin. There are dark spots or dots arranged in rows on the fins. A round black spot is on the caudal fin base. During courtship, the males turn black to blue-black.
Way of life
The species occurs in rivers, lakes, streams and swamps. She prefers calm sections in flowing water. The fish often stay on the edge of the vegetation or between sunken tree trunks or branches. The dark-bellied snakehead fish is apparently largely piscivor and is z. B. Used in aquaculture in Benin to control the excessive reproduction of tilapia species. Young fish eat copepods , insect larvae and small shrimp. The dark-bellied snakehead fish is an open spawner. During courtship, the males nod their heads vigorously and release numerous small air bubbles from the gill covers. At the point where the air bubbles collect on the surface of the water, they spawn. The brood is guarded very aggressively by the parents.
supporting documents
- ^ A b c d Melanie Stiassny, Guy Teugels, Carl D. Hopkins: The Fresh and Brackish Water Fishes of Lower Guinea, West-Central Africa. Volume 2, 2007, ISBN 978-90-74752-20-6 , pp. 241-243.
- ↑ a b Parachanna obscura on Fishbase.org (English)
- ^ A b c Walter R. Courtenay, Jr., James D. Williams: Snakeheads (Pisces, Channidae) - A Biological Synopsis and Risk Assessment. US Geological Survey circular, ISBN 0-607-93720-3 , p. 125 u. 126.
- ↑ a b Nora Brede, Pascal Antler: Snakehead fish: The genera Channa and Parachanna. Natur und Tier-Verlag, 2009, ISBN 978-3-86659-104-2 , p. 29 and 55.