An overview of domestication potential of Barbus altianalis (Boulenger, 1900) in Uganda

Domestication of fish is a key strategy for diversification of farmed species to meet consumer’s choices and demands as well as conservation of the species for sustainable provision of nutrition benefits and incomes. Initial successful induced spawning of Barbus altianalis was achieved, but there is low adoption attributed to lack of sufficient quality seed. This paper reviews the ecological and social-economic trends, and potential prospects that justify the domestication of this high value indigenous species, and identify gaps that could be addressed to increase seed production for commercialization. Review findings show that due to overexploitation, there is a steady decline of B. altianalis in Ugandan water bodies, with no current record from Lake Victoria where catches had in the past been reported. B. altianalis shows ability to survive in interlacustrine-riverine environments although, the juveniles are largely confined in the river or stream water. Varying levels of adaptability and tolerance to environmental conditions including oxygen and temperature by different age groups occur. The species has a great potential for culture as an omnivorous species with high chances of adapting to varying feeding strategies. Knowledge gaps in size at maturity, appropriate inducing hormones, growth conditions, egg hatchability and larvae weaning were identified as key challenges associated with B. altianalis domestication. Understanding the underlying natural ecological dynamics of B. altianalis will guide further research in the areas mentioned to ensure advancement in domestication so as to meet the rising demand for B. altianalis. This will curtail its overexploitation in the wild and also improve the livelihoods of the communities in the region. Keywords: Cyprinid, Omnivorous, Indigenous species, Domestication, Commercializatio

Condition factor, Length - Weight relationship, and the fishery of Barbus altianalis (Boulenger 1900) in Lakes Victoria and Edward basins of Uganda

The condition, fishing effort and environmental parameters signify health of fish populations. This study characterized differences in water quality and fishing effort in the lacustrine and riverine systems of the River Nile, Lake Edward and Kazinga channel in Uganda. One-way Analysis of Variance (ANOVA) was used to test for differences in mean relative condition among populations in the water bodies exposed to different levels of fishing effort and water quality conditions. There were significant differences in the mean relative condition (K-n) of Barbus altianalis between River Nile (mean dif 0.0880, P < 0.004) and Lake Edward and between River Nile and Kazinga channel (mean dif. 0.0796, P < 0.001). No significant difference in the mean relative condition between Kazinga channel and Lake Edward (mean diff. 0.0840, P < 0.95). Lake Edward had the highest condition (1.05), while Kazinga channel and River Nile had 1.04 and 0.96 respectively. The relationship between weight and length for each population, obtained by pooling individuals across systems was significant (P < 0.001), the length-weight allometry between the populations was also significantly different (F (2, 237) = 9.73, P < 0.001). River Nile had the highest number of fishers of 311 +/- 0.88 while the number of fishers in Lake Edward and Kazinga channel were 75 +/- 2.45 and 33 +/- 9.12, respectively. Catch rates varied between River Nile (1.92 +/- 0.59 Kg boat(-1) day(-1)) and the rest of the systems, 6.20 +/- 1.86 and 6.85 +/- 1.49 Kg boat(-1) day(-1) in Lake Edward and Kazinga channel respectively. Water quality varied greatly across all the water bodies. Dissolved oxygen was below the minimum of 5 mgl(-1) required for the physiology of freshwater fish. Conductivity was highest in Lake Edward (312 A mu S cm(-1)), followed by Kazinga channel and least in River Nile. The consistent variation in condition, fishing effort and water quality, indicates differential selective pressures faced by B. altianalis in the systems and therefore calls for concerted efforts for appropriate management measures