Nile tilapia (Oreochromis niloticus) aquaculture continues to significantly contribute to the growth of the aquaculture sector in Uganda. However, its production is beset by erratic and unreliable seed supply. Also, most hatcheries practice inbreeding of broodstock, resulting in inferior seed characterized by low growth rates. As such, a selective breeding program is necessary to readily avail fast-growing seed that respond to farmers’ needs. The present review consolidates available information on developing a Nile tilapia breeding program in Uganda. The article discusses the significance of genetic improvement, drawing lessons from successful Nile tilapia selective breeding programs in other countries. From a literature review, no systematic Nile tilapia selective breeding program was traceable in Uganda. Scanty information on the selective breeding efforts of the species was available, with little evidence of selection for improved performance. Overall, the national capacity for aquaculture research and development, including fish breeding and strain improvement, was weak and poorly funded. The review recommends purposive support for developing a systematic strain improvement breeding program, which will be a source of improved broodstock and seed for hatcheries and farmers, respectively. The program would guide the formulation of standard operating procedures for quality seed production towards ensuring sustainable aquaculture growth in Uganda.

In Uganda fish is a great source of animal dietary protein, however, natural stocks continue to decline. Therefore, aquaculture provides a viable option to bridge the increasing fish supply-demand gap. Accordingly, a study was conducted from March to August 2016 to investigate the effect of stocking density on the growth performance, and survival of Nile tilapia (Oreochromis niloticus) in floating net-cages to contribute to aquaculture production in Uganda. Nile tilapia fingerlings, with an average weight of 4.07 g were stocked in 8 m3 cages at three different stocking densities; 200, 250, and 300 fish/m3, and fed on a locally formulated commercial feed for 180 days. At the end of the experimental period, results showed that fish stocked at lower densities were heavier than those stocked at higher densities. The mean final weights of fish were; 150.79±85.71, 127.82±68.43 and 118.73±49.29 g in cages stocked with 200, 250 and 300 fish/m3, respectively. The mean final weight in lower density (200 fish /m3) treatments was significantly higher (P0.05) among the stocking densities. Survival rate and stocking density were negatively correlated. The best survival rate (94.19%) was obtained in low stocked cages (200 fish/m3) compared to 92.98% in highly stocked cages (300 fish/m3). The results of this study suggest that 200 fish/m3 of a cage, is the best stocking density in terms of fish growth parameters. Key words: Aquaculture, animal protein, per capita, livelihood, yield.

Despite the importance of Nile tilapia as a main aquaculture species in Uganda, limited research has been conducted concerning its genetic diversity, particularly in farmed populations. This gap has hindered the development of a systematic breeding program for this species. Successful aquaculture development, especially for genetic improvement, relies on the diversity and purity of wild and farmed populations as germplasm sources for selective breeding. Using microsatellite markers, the current study evaluated the genetic diversity of 480 samples collected from 20 populations of Nile tilapia (Oreochromis niloticus) in Uganda. All the populations exhibited a higher expected heterozygosity (0.50 ± 0.01) than observed heterozygosity (0.42 ± 0.01), although this was not significantly different. Populations from ponds showed lower FST values (<0.001), an indication of lower genetic differentiation. The populations formed four main clusters; the first comprising of mainly cages (Pal and Busana), the second with cages: Katosi and SON in addition to Rocks hatchery, the third comprised of Bawe cage fish farm and Tendo hatchery, and the fourth were populations from ponds and beaches on Lake Victoria. Given the higher genetic diversity and genetic differentiation of Tendo and Rocks populations, these farms would provide potential candidates for the development of local strains in Uganda. These results provide more insights into the management of local Nile tilapia strains towards reduction of inbreeding levels.

Aquaculture sector if fully exploited has great potential of boosting foreign exchange, household nutritional and income levels. However, not much has been done regarding economic analysis of aquaculture production to attract and guide investment. This study was carried out to assess the profitability and viability of the aquaculture enterprises in central Uganda. The study focused on the socioeconomic and production characteristics, profitability indices and significant challenges experienced by the fish farmers. The fish farmers were selected using simple random and purposive method from the farmers’ lists provided by the Aquaculture Research Centre. The study was carried out in Kampala, Mukono and Wakiso districts between July and August 2015 using well structured questionnaire complemented with interview schedule. The collected data were analysed using descriptive statistics and pseudo-profit function. The results indicated that male aquaculturists owned the majority (86.8%) of the farms. On the average, a majority (77.4%) of the respondents’ cultured tilapia as the primary species. The Tilapia and African Catfish culture periods lasted for 8 and 9 months to attain an average body weight of 0.5kg and 1kg, respectively. The operational costs accounted for 2736000 and 2865960 Uganda shillings of the total tilapia and catfish production cost. A kilogram of tilapia and catfish were sold at 10800, and 9360 Uganda shillings, respectively and positive gross margins were reported for both species. The fish farmers still faced challenges of expensive fish feeds, predators and water quality problems due to increasing urbanisation. The study recommended the need for farmers to re-organise themselves into cooperatives to collectively purchase inputs, train farmers in business management skills to run aquaculture as sole business entities, stocking of monosex tilapia for easy control of tilapia populations and efficient feed utilization to reduce the current feed conservation ratios.

Effect of type of nutrient media on the biomass and fatty acid profiles of microalgae (Chlorella spp.)