Wageningen Aquaculture is a consortium of IMARES (Institute for Marine Resources & Ecosystem Studies) and AFI (Aquaculture and Fisheries Group, Wageningen University), both part of Wageningen University & Research Centre (WUR).
Spawning migrations of the endemic Labeobarbus (Cyprinidae, Teleostei) species of Lake Tana, Ethiopia: status and threats
Article first published online: 17 JUL 2012
© 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles
Journal of Fish Biology
Special Issue: Fish Migration in the 21st Century: Opportunities and Challenges
Volume 81, Issue 2, pages 750–765, July 2012
How to Cite
Anteneh, W., Getahun, A., Dejen, E., Sibbing, F. A., Nagelkerke, L. A. J., De Graaf, M., Wudneh, T., Vijverberg, J. and Palstra, A. P. (2012), Spawning migrations of the endemic Labeobarbus (Cyprinidae, Teleostei) species of Lake Tana, Ethiopia: status and threats. Journal of Fish Biology, 81: 750–765. doi: 10.1111/j.1095-8649.2012.03362.x
- Issue published online: 17 JUL 2012
- Article first published online: 17 JUL 2012
- large cyprinids;
- reproductive segregation;
- riverine spawning migration;
- species flock
The reproductive biology of the only known intact species flock of large cyprinids, the 16 Labeobarbus species of Lake Tana (Ethiopia), has been extensively studied for the past two decades. Seven species of Labeobarbus are known to migrate >50 km upstream into tributary rivers for spawning during the rainy season (July to October), whereas eight other species are absent from these rivers and probably developed a new strategy of lacustrine spawning (macro-spatial segregation). One species (L. intermedius) probably spawns in the lake as well as in the rivers. Between the early 1990s and 2000s, the riverine spawners showed a decline of 75% in both biomass and number in both fishery independent surveys and in commercial catches. Reproductive migration makes fishes vulnerable to fisheries and other threats like habitat modifications. Lacustrine spawners are probably more resilient as they are not known to form spawning aggregations that can easily be exploited by fishermen. In addition, upstream rivers and catchments around Lake Tana are highly degraded by erosion and recently subjected to intensive habitat modification for irrigation and hydroelectric power generation. This article reviews results of field studies on the Labeobarbus spawning migration from Lake Tana to spawning rivers, giving emphasis on segregation and homing. It also summarizes existing and emerging threats which form potential causes for the decline of the migratory Labeobarbus species. Knowledge gaps on the reproductive biology are identified for further investigation.