African Journal of Fisheries Science Vol. 2 (9), pp. 176-184, September, 2014. © International Scholars Journals

Full Length Research Paper

Spawning migration of Labeobarbus species of Lake Tana to Gilgel Abay River and its tributaries, Blue Nile Basin, Ethiopia

Dagnew Mequanent1, Minwyelet Mingist2, Abebe Getahun3 and Wassie Anteneh4

1Amhara Design and Supervision Works Enterprise, P.O.Box1921,Bahir Dar, Ethiopia.

2Department of Fisheries, Wetlands and Wildlife Management, College of Agriculture and Environmental Sciences, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia.

3Department of Zoological Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.

4Department of Biology, College of Science, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia.Email:  dagnewm5@gmail.com

Accepted 31 July, 2014

Abstract 

Fish samples were collected by using monofilaments gillnets (5-55 mm) and multifilament gillnets, having mesh sizes of six, eight, ten, twelve and fourteen centimeter stretched bar mesh, having a length of twenty five meter and depth of one and half meter, on six sampling sites of Gilgel Abay River and its tributaries. Dissolved Oxygen, water temperature, pH, conductivity, total dissolved solids and water transparency were measured. Samples were collected bimonthly from August to October and monthly in November. When all catches are pooled, 89.30% was contributed by the genus Labeobarbus and the remaining (5.7%) and (5%) were from the genera Clarias and Varicorhinus, respectively. Labeobarbus intermedius was the most dominant (50.10% by number), followed by L. brevicephalus (17.16%) and L. nedgia (8.58%). Spatial distribution patterns of the most abundant Labeobarbus species did not show significant variation (P >0.05). Temporal segregation among dominant Labeobarbus species was not also evident (P >0.05) except, between L. intermedius and L. brevicephalus. All Labeobarbus spp. except L. dainellii, L. gorguari, L. acutirostris and L. megastoma were found in all sites. Illegal fishing activities were rampant and must be totally prohibited by closing fishing during the spawning months to protect these unique migratory riverine spawning species.

Key words: Conservation, segregation, abundance, temporal, Labeobarbus, migration.