THE PREVALENCE OF ENDOPARASITES IN THE GASTRO-INTESTINAL TRACTS OF NILE TILAPIA (OREOCHROMIS NILOTICUS) IN GIRI RIVER, GWAGWALADA AREA COUNCIL, FCT-ABUJA
CHAPTER ONE
Fishing is an important component of aquaculture in Nigeria. Fish is important as a source of protein with low cholesterol level in the diets of the populace and economically as a source of subsistence income (Aken’ova, 2000). In line with the increasing aquaculture activities, substantial information has been generated on aquaculture-related subjects in the country. An exception is fish diseases. Outbreaks of disease, however, constrain sustainable aquaculture production unless comprehensive management strategies are in place (Subasinghe et al, 2001; Bondad-Reantaso et al. 2005). Preliminary investigations into disease outbreaks in fish farming systems have reported a number of conditions resulting in mortality (Akoll 2005; Florio et al. 2009). Scarcity of information on aetiological agents hampers the development of cost-effective and ecologically
sustainable strategies for disease control (Subasinghe et al. 2001; Bondad- Reantaso et al. 2005). With high fish stocking densities under commercial fish production, parasite outbreaks will undoubtedly increase (Michel 1989; Meyer 1991; Bondad- Reantaso et al. 2005).
All fishes are potential host to many different species of parasites that cause significant mortalities among captive and wild fish stocks. The crowding effects and frequent water deterioration provide ideal conditions for the transmission and proliferation of parasites, particularly for species with direct life cycles. Moreover, it is a common practice to polyculture Oreochromis niloticus with Clarias gariepinus in an attempt to control the proliferative reproduction of tilapia in Uganda. However, variation in host specificity between and within parasite groups, especially monogeneans, polyculture pose a threat of parasite cross-transmission (Sasal et al.
1999; Bakke et al. 2002; Cribb et al. 2002). Due to differences in host immunity, infection with parasites from different hosts may inflict strong pathologies and possibilities of mortalities. Accurate identification of parasites is therefore important so that a build-up of parasite numbers can be prevented. Fish health and fish diseases are becoming more important as certain fish species are becoming more important as a ready food source for growing populations of not only the United States, but other countries as well. Parasites are found in both captive and wild fish populations, but in wild populations they maintain a kind of equilibrium until something happens to upset that balance.
