Prevalence of gastrointestinal parasites in tilapia (Oreochromis niloticus) in Port Harcourt, Rivers state, Nigeria

The study aimed to investigate the prevalence of gastrointestinal parasites in Oreochromis niloticus sold in major markets in Port Harcourt, Rivers State, Nigeria. A total of 120 specimens of different size groups were randomly sampled from three (3) markets in Port Harcourt and examined for parasites. The overall frequency and percentage prevalence recorded was 80 (66.67%) with the highest parasitic infection obtained in Rumuokoro market samples. Out of the total fish sampled, the prevalence of gastrointestinal parasite in O. niloticus sampled from Oil Mill market was 26 (21.6%), Rumuokoro market 30 (25%) and Rumuola market 24 (20%). The overall prevalence showed significant difference (p = 0.005) in all the markets. However, percentage prevalence between sex showed no significant difference (p = 2.46), with male fishes known to have a higher prevalence of infection. The recovered parasites were protozoans>nematodes>cestodes>trematodes in order of prevalence as 40 (33.3%) > 30 (25%) >16 (13.33%) >12 (10%) respectively. Thus, protozoans showed the highest prevalence in O. niloticus. In conclusion, fish specimens were found to be infected with various gastrointestinal parasites, this may lead to reduction in productivity. Keywords: Parasites, digestive system, prevalence, Oreochromis niloticus, Port Harcourt