Parasites of Farmed and Wild Tilapine Fishes From Selected Farms and Lake Jipe in Taita Taveta County, Kenya

Abstract

Parasitic infections threaten the endangered Oreochromis jipe and other ichthyic populations in Lake Jipe, thereby hindering conservation efforts. Initiatives have been made to farm O. jipe as a conservation strategy. To develop effective conservation approaches and ensure the species' survival in its natural habitat and aquaculture systems, it is imperative to understand the diverse parasites in these habitats. Consequently, this cross-sectional study was conducted to determine parasitic loads in tilapias from selected farms and Lake Jipe. A total of 111 fishes were collected (76 farmed, 35 from the lake), comprising 66 O. jipe, 34 Oreochromis niloticus and 11 hybrids of O. jipe and O. niloticus. The fish were euthanized, necropsied and examined for parasitic infections via visual inspection and light microscopy. Out of 111 fishes examined, 58 (52.3%) were infected with 212 parasites, including 135 (63.7%) and 77 (36.3%) from farm and lake habitats, respectively. The prevalence of parasitic infections in fish from the lake and farm habitats was 68.6% and 44.7%, respectively. The most frequently occurring parasite genera identified were Diplostomum (30.63%), Acanthocephalus (20.7%), Dactylogyrus (9.9%) and Contracaecum (2.7%), with mean intensities of 2.9, 3.7, 1.9 and 1.7, respectively. Contracaecum and Camallanus were exclusively found in fish from Lake Jipe, while Euclinostomum and Gyrodactylus were only observed in farmed fish. O. jipe had the highest prevalence of parasitic infections (59.1%), followed by O. niloticus (44.1%) and hybrids (36.4%) (p > 0.05). In conclusion, the examined fishes were infected with diverse parasites, which have both public health concerns (Euclinostomum and Acanthocephalus) and economic significance (Dactylogyrus and Gyrodactylus). Consequently, it is imperative to enhance public awareness and enforce biosecurity measures to mitigate potential health risks and to improve the productivity of the pond culture system and lake ecosystem. These measures will help reduce parasite dissemination and promote sustainable fish production and populations.