Assessment of Factors Affecting Parasite Prevalence and Condition Factor in Farmed Fish of the Western Region of Cameroon

Abstract

Fish production is an essential livelihood sector in Western Cameroon contributing significantly to food security and employment opportunities. Currently, it faces challenges from parasitic diseases. This study assessed the abiotic drivers of parasitism and their impact on the condition factor of three farmed fish species (Oreochromis niloticus, Cyprinus carpio, and Clarias gariepinus) in the Western Cameroon. Between December 2018 and December 2019, 2,254 fish were sampled monthly from ponds and concrete tanks and examined using standard parasitological procedures, while water physicochemical parameters were measured simultaneously. Results showed that the overall parasite prevalence was 39.66%, dominated by ectoparasites (34.87%). Only 8.47% of endoparasites were found (Acanthocephalus sp. and nematodes). Parasite prevalence was significantly (p<0.05) higher during the dry season (46.01%) in non-integrated ponds, on farms managed by less-educated farmers, and with higher feeding frequency. The Principal Component Analysis indicated temperature, turbidity, phosphate, and iron are positively correlated to parasite prevalence, while dissolved oxygen showed a negative association. Although no mortality was recorded, parasitized fish had a significantly (p<0.05) lower condition factor (2.53±2.10) compared to non-infected fish (2.90±2.72). It was concluded that, in Western Cameroon fish farms, parasite prevalence is increased during dry season, high temperature, turbidity, and feeding frequency. Non-integrated pond systems and farms operated by low-educated farmers revealed a high parasite prevalence affecting the condition factor in infected fish. To address the issue, efforts should be focused on water quality management, feeding practices, and farmer training.