Some biological aspects of Labeobarbus spp. (Pisces: Cyprinidae) at Arno-Garno River, lake tana sub-basin, Ethiopia

Abstract

The reproductive biology of Labeobarbus species in Arno-Garno River was studied from July 2010 to June 2011. Fish were sampled monthly in the non-peak spawning season and twice in the peak spawning season using 6, 8, 10, 12 and 14 cm mesh size gill net. A total of 1077 Labeobarbus specimens were collected within the six sampling months from all sampling sites. Out of the total catch of Labeobarbus the four dominant species contributed 93.03%. From the index of relative importance, L. intermedius was the most dominant species which contributes 44%. Length-weight relationship of the four dominant Labeobarbus species was curvilinear and statically significant (p<0.001). Fulton's condition factor was lower for females than males for L. intermedius and L. brevicephalus and showed significant variation for L. intermedius during the peak and non-peak spawning months (p<0.001). Except, L. nedgia, the remaining Labeobarbus species were significantly different (χ2, p<0.05) from the theoretical 1:1 ratio. The average fecundity for L. intermedius and L. brevicephalus were 4607 and 4085, respectively. The relationship of absolute fecundity with Fork length, total weight and gonad weight of the two species was linear and significant (p<0.05). The monthly gonad-somatic indicated that the spawning season for Labeobarbus species was from August to October. Hence, closing season should be strictly implemented. © 2014 Academic Journals Inc.