Food and feeding habits of three air-breathing fish in its natural habitat

Abstract

Food and feeding habits of three air-breathing fish namely climbing perch Anabas testudineus (Bloch) (Perciformes: Anabantidae), the walking catfish Clarias batrachus (Linnaeus) (Siluriformes: Clariidae), and the stinging catfish Heteropneustes fossilis (Bloch) (Siluriformes: Heteropneustidae) under natural conditions and the manner in which dietary preferences are influenced by the habitat, seasonal and stage of maturity of the fish are explained, based on data form monthly randomly collected samples for a year. Qualitative assessment of the diet reveals that it is not restricted to a varied range of aquatic fauna, but also encompasses allochthonous fauna. Size or season changes do not alter the diet of these fishes. Range of prey consumed by this fishes 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 seems to be dependent on the occurrence of food organisms. To conclude, the potentiality of these three air-breathing fish as an effective biological control agent of mosquito larvae is indicated by the fact that dipteran larvae are preferred item of its diet mainly in small and medium sized group of fish.