Food and feeding habits of the larvivorous fish Aplocheilus lineatus (Cuv. & Val.) in its natural habitat

Abstract

Results are presented of a study of the food and feeding habits of Aplocheilus lineatus under natural conditions and the manner in which dietary preferences are influenced by the habitat/environment, seasons and stage of maturity of the fish is explained, based on data from montly random samples collected for a year. A qualitative assessment of the diet reveals that it is not confined to a varied range of aquatic fauna, but also encompasses allochthonous fauna. Quantitative and qualitative analyses of the diet indicate its feeding habit which does not alter with size or seasonal changes. The range of prey consumed does not differ radically, qualitatively, as a function of size, but quantitatively exhibits five levels of discrimination and differential exploitation related mainly to prey size. Seasonal fluctuations in feeding are more qualitative than quantitative and seem dependent on the occurrence of food organisms. The lack of correlation between breeding and feeding is linked to extent of the development of the gonad in the body cavity. In conclusion, the potential of the fish as an effective biological control agent of mosquito larvae is indicated by the fact that dipteran larvae are a preferred item of its diet in all size groups.