Dietary Diversity of Crayfish (Procambarus clarkii Girard 1852) (Crustacea, Decapoda) in Herbaceous Vegetation Dominated Swamps in Uasin Gishu, Kenya

The feeding ecology of red swamp crayfish (Procambarus clarkii Girard 1852) in terms of food and feeding habits was conducted in two sympatric East African wetlands (Uasin Gishu, Kenya) between February and November, 2012. Microscopic examination of the gut content of 320 P clerkii in the two swamps, showed distinct tendency towards herbivory with dominance of plant materials, algae and lower abundance of insects. There were no significant (p greater than 0.05) differences in the overall composition of food items between the two swamps. The electivity values for pooled data in the two sites showed a strong negative electivity for rotifers and, to a minor extent, for molluscs. Also P. clerkii showed significant (p less than 0.05) ontogenetic variation in the diet. Plant materials, crustaceans and molluscs increased in proportion with respect to size class as they could not be digested by young P. clerkii while insects and algae reduced with increasing age classes. Overestimation of herbivory and detrivory in this omnivorous species may indicate diet complexity in the tropical swamps in an environment dominated with dense herbaceous plants species