Prevalence and Diversity of Gastrointestinal Parasites and Fungal Flora of Nile Tilapia (Oreochromis niloticus) from Komadugu River, Gashua, Yobe State, Nigeria

Abstract

Aims: This study assessed the prevalence and diversity of gastrointestinal parasites and fungal flora in Nile tilapia (Oreochromis niloticus) obtained from the Komadugu River in Gashua, Yobe State, Nigeria, and evaluated the implications for fish health and food safety. Study Design: Descriptive cross-sectional parasitological and mycological survey. Place and Duration of Study: The Biological Sciences and Microbiology Laboratory, Federal University Gashua, Yobe State, Nigeria, during the rainy season. Methodology: A total of 100 fish specimens were collected using a cast net. Morphological data (sex, length, and weight) were documented before processing. Each fish was dissected, and the gastrointestinal tract (including the oesophagus, stomach, intestine, and rectum) was examined following sedimentation, flotation, and mycological isolation procedures. Parasites and fungal structures were isolated in normal saline and identified morphologically under light microscopy using the ×10 and ×40 objectives. Results: Of the 100 fish examined, the overall prevalence of gastrointestinal pathogen infestation was 30.00%. Three distinct parasitic and fungal taxa were identified: the zoonotic cestode Diphyllobothrium latum (13.00%), the opportunistic dermatophytic fungus Trichophyton rubrum (9.00%), and the kinetoplastid Trypanosoma chagasi (8.00%). Female fish showed a higher infection rate (37.50%) than males (23.08%), although the difference was not statistically significant (P = .32). Biometric analysis showed that fish measuring 19.00 cm in length exhibited the highest prevalence within their subgroup (26.32%), while those measuring 20.00 cm had the lowest (20.00%) (P = .59). Similarly, fish weighing 85.22 g recorded the highest group infection rate (26.66%), whereas those weighing 109.00 g had the lowest prevalence (20.00%) (P = .59). Conclusion: The observed 30% prevalence underscores a moderate level of gastrointestinal infestation and fungal colonisation, which may pose potential health risks to consumers due to zoonotic taxa such as D. latum and the opportunistic nature of T. rubrum. Routine parasitological and mycological surveillance, environmental sanitation of the river ecosystem, and community awareness regarding proper fish cooking practices are recommended.