ABSTRACT:Disease is an important factor in fisheries, affecting both wild and cultured species. Using standard parasitological techniques we determined the prevalence, mean intensity and abundance of endoparasites from 250 specimens of two cichlids, Oreochromis niloticus and Tilapia zilli from Asa dam, Ilorin, North Central Nigeria between February and August, 2013. We found two digenetic trematode parasites: Euclinostomium heterostomum and Clinostomum tilapiae. The highest prevalence was recorded in O. niloticus (35,9%) infested by C. tilapiae, while the highest mean intensity was recorded in T. zilli. There was no relationship (p >0,05) between parasite burden and fish size (length and weight). Male fish were more heavily infected than females. The overall health status of both fish species remained unaffected. The high rate of pollution noticed in the study area might be favoring parasite load. Therefore, pollution control and regular surveillance of the water body are advocated.Key words: parasites; flatworms; cichlids; Asa Dam; Nigeria.
RESUMEN:Las enfermedades son un factor importante en la pesca, afectando especies silvestres y cultivadas. Mediante el uso de técni-cas parasitológicas estándar se determinó la prevalencia, intensidad y abundancia de endoparásitos en 250 especímenes de dos cíclidos, Oreochromis niloticus y Tilapia zilli de la represa Asa, Ilorin, Nigeria del Norte Central, entre febrero y agosto del 2013. Encontramos dos parásitos trematodos digenéticos; Heterostomum Euclinostomium y Clinostomum tilapiae. La prevalencia más alta se registró en O. niloticus (35,9%) que fue infestado por C. tilapiae, mientras que la media más alta de intensidad se registró en T. zilli. No hubo relación (p>0,05) entre la carga parasitaria y tamaño de los peces (longitud y peso). Los machos fueron más infectados que las hembras. El estado de salud de las dos especies de peces no se vio afectado. La alta tasa de contaminación en el área de estudio podría ser responsable de la aparición del parásito registrado. Por lo tanto, se recomienda el control de la contaminación y la vigilancia regular de la masa de agua.Palabras clave: parásitos; platelmintos, cíclidos; represa Asa; Nigeria.Disease is an important factor in fish production, and this commercially important source of animal protein is susceptible to infections with various parasites (Emere, 2000). Helminthes are among the most important parasites and include nematodes, trematodes, cestodes and acanthocephalans affecting both wild and cultured fishes (Hussen, Tefera & Asrate, 2012). These diseases are closely linked to environmental deterioration and stress. The importance of parasitic infection on fish production has remained an issue of concern to fish farming industry. Fishes especially the cichlids are widely distributed in African water bodies due to their high productivity rate and their ability to adapt to various climatic conditions (Onwuliri & Mgbemena, 1987). Parasites usually compete for food thereby depriving fish of its essential nutrients as suc...