Guruge, W.A.H.P, Amarasinghe N.J.De. S

BS, BD, and MYS species get decreased in post droughtperiod. This can be attributed to the major foodcategories consumed by these species. Especially, BSmainly depends heavily on molluscs and insect mattersand due to the desiccation in the drought period themollusc populations declined. Consequently, thesesspecies switched to a larger spectrum of food resourcesthat were available in the environment at that time.The drought caused persistence disturbanceduring which, as long as it remains, the community canexperience other problems depending on the waterlevel. Effect of drought on changes of food and feedinghabits of fish could be taken into account for bettermanagement of fisheries in reservoirs.References1. Baldwin. M.F 1991. Natural resources of SriLanka: conditions and trends. Natural resources,energy and science authority of Sri Lanka,colombo.260 p2. De Silva, S.S. 1988. Reservoirs in Sri Lanka andtheir fisheries. FAO Fisheries technical paper No.298, 128 pp3. Schoener, T.W.1974 Resource partitioning inecological communities. Science 185: 27-394. Begon, M. Harper, J.L, Townsend, C.R. 1986.EcologyBlackwell Sceintific Publication, Oxford.876 p.5. Cone, R.S. 1989. The need to reconsider the use ofcondition indices in fishery science. Trans.Amer.Fish.Soc. 118: 510-514.6. Kalk, M., Mc Lachian, A.J, & Howard-Williams,C. 1979. Lake Chilawa. Studies of change intropical ecosystem. Monographiae BiologicaeVolume 35. Dr. W. Junk Publishers, The Hague.462 p.7. Hynes, H.B.N. 1950. The food of fresh-watersticklebacks (Gasterosteus aculeatus andpygosteus pungitius) with a review of methodsused in studies of the food of fishes. J. Anim. Ecol.19: 36-588. Schoener, T.W. 1970. Nonsynchronus spatialoverlap of lizards in patchy habitats. Ecology.51:408-418.9. Moyle, P.B. & Senanayake, F.R.1984. Resourcepartitioning among fishes of rainforest streams inSri Lanka. J. Zool. Lond. 202: 195-223.10. Levins, R. 1968. Evolution in changingenvironments:Some theoretical explorations.Princeton University press, Princeton.11. Wallace, R.K. 1981. An assessment of diet-overlapindexes. Trans. Am. Fish. Soc. 110:72-76AcknowledgementFinancial support from the Netherlands Foundation forthe advancement of Tropical Research (WOTRO), thecentre for Limnology of the Netherlands Institute ofEcology is highly acknowledged.