Influence of level of farm management and correlation of water quality in the parasitosis of Nile tilapia (Oreochromis niloticus L.) in selected grow-out farms in Central Luzon Philippines

Abstract

The present study recorded six genera of ectoparasites (Trichodina spp., Coleps spp., Euplotes spp., Dactylogyrus spp., Gyrodactylus spp. and Ergasilus spp.) and three taxa of endoparasites (Camallanus spp., and unknown digenean and acanthocephalan) from the gills and skin, and intestine, respectively of the examined Nile tilapia in Central Luzon, Philippines. The study revealed that farms receiving intensive level of management (>7 fish/m2) had the highest parasites’ load as compared to semi-intensive (4 to 6 fish/m2) and extensive system (1 to 3 fish/m2). Moderate fish stocking in semi-intensive system is an advantage on the reduction of parasite infestation and transmission. In extensive level of management, even of low stocking density, fish were just stocked and not provided with good husbandry. This kind of practice also resulted to higher infestation and easy spread of ectoparasites. Environmental factors such as the physico-chemical properties of water could influence the level of parasitosis in pond-reared tilapia but show little consistency in the present results.