Gut analysis of the freshwater shrimp Caridina nilotica ("Ochong'a") for its conservation in the face of its extensive utilization in aquaculture and climate change in Lake Victoria, Kenya

The aquaculture industry is expected to double by the year 2050 but has not yet reached its full potential in East Africa. Tilapia makes up 75% of the freshwater fish production in Kenya, but the high cost of commercial fish feed is limiting the expansion of the industry. The freshwater shrimp Caridina nilotica is an established alternative to fishmeal in the production of the commercial feed, but its accessibility is limited to the natural stocks in Lake Victoria. Towards this end, this study investigated the gut contents of Caridina nilotica. One hundred specimen of C. nilotica were caught from Usoma Beach, in Winam Gulf of Lake Victoria. They were dissected and their gut samples were examined under a microscope. Every observed gut content were photographed and their frequency of occurrence recorded. Our findings showed that the main food for the C. nilotica was algae. The algal species were identified based on their morphology, color, and overall shape. The mean total body length of the examined C. nilotica was 2.12 ±0.29cm (±SD). Thirteen genera were identified from 6 divisions. The identified genus included; Microcystis sp., Surirella sp., Staurostrium sp., Synechococcus sp., Pediastrium sp., Synedra sp., Oocystis sp., Hantzschia sp., Oscillatoria sp., Fragilaria sp., and Glaucocystis sp. Merismopedia sp. (Cyanobacteria) and Botryococcus sp. (Chlorophyta) were abundant. C. nilotica mainly feed on algae from the division Chlorophyta, with diatoms and Cyanobacteria also being common. The information obtained in this study can be used to develop protocols for mass C. nilotica cultivation.