Association of size structure, diet composition, endo-parasites of Snakehead fish (Channa striata, Bloch), in Lake Mainit, Caraga Region, Philippines

Abstract

Channa striata Bloch is a type of indigenous freshwater fish abundant in Lake Mainit and it serves as a source of foods and finances of the people. This species was reported as an intermediate host of many helminth parasites. This research aimed to determine the association of endo-parasites, diet composition, and length and weight in snakehead fish C. striata Bloch in three selected municipalities along Lake Mainit, Caraga Region, Philippines. The results revealed that food items found in the stomach of the fish were mostly composed of shrimps, plant debris, fish, crab, detritus (dry & wet seasons), aquatic insects and snail (wet season). Among the seven food items, highest index of relative importance (IRI) value observed are shrimps in both wet and dry seasons. A nematode parasite was recovered in the gut of the fish samples. Out of 180 fish samples, 133 were infected with Procamallanus sp. The prevalence was higher in the dry season compared to the wet season. However, parasite intensity and diet count of C. striata Bloch. showed no significant variations between sampling sites and seasons. On the other hand, there were no significant differences between the intensity of the parasite count to the length and weight of the fish; the association between parasite count and diet count during dry and wet seasons showed a strong positive correlation. The results indicated that C. striata Bloch is susceptible to Procamallanus sp. nematode infection because of its carnivorous diet and serves as the vector or intermediate host in freshwater. Thus, more fish samples, the host’s age, host’s sex, the study gap, infection rate of the fish organs, and assessment of the physico-chemical parameters in future studies must be used.