Gonadal recrudescence and induced spawning in Barbus altianalis

Gonadal recrudescence in Barbus altianalis from River Nile, Jinja (33 degrees 05E; 0 degrees 45N) Uganda was studied prior to induced spawning. Oocytes in B. altianalis were found to develop in cohorts suggesting batch spawning throughout the year with pronounced spawning activities coinciding with rainfall peaks of April and September. There was a strong positive correlation between rainfall and gonadosomatic index (r(S) = 0.75, P = 0.008). B. altianalis had low fecundity (6.0 +/- 2.0 per gram) and large-sized eggs (2.97 +/- 0.1 mm). Induced spawning was successful with exogenous hormones and water current. Results from this study suggested that total striping may not be appropriate, but larger eggs would confer high survival of offsprings under optimal conditions. The success registered in induced spawning of B. altianalis provides a breakthrough in seed production for multiplication and culture of this economically important fish species.