This paper reviews the current status of freshwater aquaculture in both India and Uganda. India has a long history of aquaculture, dating from the 4 th century. Subsequently, the country has become a major contributor to global aquaculture and is believed to have more than 10% of the global fish diversity. Currently, India is the second largest aquaculture producer in the world with global contribution of 6.3% and the major contribution comes from freshwater aquaculture, whose share has gone up from 46% in the 1980s to over 85% in the recent years. Since 1980s, India has emerged as one of the largest investors and trading partners of Uganda. As such, there is much that Uganda can adopt from the India's freshwater aquaculture given their political, social and economic relations established overtime between the two countries. As the largest producer of Indian major carps, India has set the pace for change and innovation in culture practices since the 1960s. Uganda's aquaculture is also undergoing changes to meet the challenges of increasing demand, such comparisons through comprehensive literature review and case studies can form a strong foundation for future investment in aquaculture. In addition, generating information for each country's comparative advantage in aquaculture can assist in developing strategies for structural adjustment programmes. Some of those strategies, might promote integration of economic activities, human capacity building, information sharing and technology transfer.

Gonadal recrudescence in Barbus altianalis from River Nile, Jinja (33°05E; 0°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 AE 2.0 per gram) and large-sized eggs (2.97 AE 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.

SynopsisWe investigated aspects of the reproductive biology of the cyprinid fish, Labeo victorianus, locally known as ningu, in the Kagera and Sio Rivers, Uganda. These rivers represent the last remaining refuges for this species within Uganda. L. victorianus is a highly fecund, potamodrometic fish that migrates upstream to spawn. Spawning is generally synchronised with the bimodal water level maxima observed within the rivers. There were, however, some deviations from this pattern. We caught sexually mature fish throughout the year in the Sio River, and noticed that spawing started before the second rainfall peak. Fish from the Kagera matured at significantly larger sizes than fish from the Sio River. Male and female fish, from both rivers, fed intensively during the non-breeding months accumulating significant fat reserves; a probable energy storage mechanism prior to their spawning migrations. The differences between the populations is probably a phenotypic response to differing abiotic factors such as river size, flow velocity and food availability.

No abstract

Two spawning inducing agents—Aquaspawn (a rapidly metabolized synthetic decapeptide gonadotropin‐releasing hormone [GnRH]) and Dagin ([D‐Arg6, Pro9‐NEt]‐sGnRH) combined with 20 mg/kg of the water‐soluble dopamine receptor antagonist metoclopramide (GnRH + MET)—were tested for their efficacy in stimulating ovulation in Labeo victorianus held in its natural environment and under captive conditions. Successful ovulation, when migratory vesicle oocytes became completely transparent, was obtained with GnRH + MET, while GnRH only caused oocyte clearance up to the highly translucent phase. L. victorianus eggs were non‐adhesive, semi‐buoyant, and transparent at ovulation. First hatching occurred after 26 h and lasted for 8 h at 24 C. Water temperature was shown to significantly affect spawning latency and incubation time. Thus, L. victorianus could be successfully induced to spawn using a synthetic gonadotropin‐releasing hormone coupled with a dopamine antagonist followed by natural fertilization in floating net cages at temperatures between 24 and 27 C.