Habitat heterogeneity and prey selection of Aplocheilus panchax: an indigenous larvivorous fish.

OBJECTIVE The ability of the native larvivorous fish Aplocheilus panchax (Hamilton, 1822) (Cyprinodontiformes: Aplocheilidae) as predator of mosquito larvae was assessed under laboratory conditions using multiple prey and habitat conditions. METHODS The consumption of larvae of the mosquito Culex quinquefasciatus Say 1823 (Diptera: Culicidae) by A. panchax was evaluated in the presence of tubificid worms and chironomid larvae under complex and simple habitat conditions. The number of mosquito larvae consumed in comparison to other prey types was noted and an index of prey selectivity was used to evaluate the preference for mosquito larvae. RESULTS Aphlocheilus panchax consumed 53 to 65 mosquito larvae in a three hour feeding bout contrast to 29- 38 tubificid worms and 43-62 chironomid larvae depending on the habitat conditions. The prey consumption differed significantly between the habitats and the prey type. The index of prey selectivity was positive for Cx. quinquefasciatus larvae over other alternative prey in all the habitat conditions. CONCLUSION It is apparent from the study that the larvivorous fish A. panchax can be employed for biological regulation of mosquitoes in rice -fields and similar wetlands where the multiple prey choices are available under complex habitat conditions. However, field studies including other prey species will be required to substantiate this finding.