4.Journals Published in Sri Lanka
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Item An ecological study of the mangrove fauna in the west coast of Sri Lanka(Univer, 1986-87) De Silva, K.H.G.M.; De Silva, P.K.Item Importance of ectoparasitic ciliate infestations in the farming of snakehead fishes (Channa spp.) (Teleostei:Channidae) in Sri Lanka(Univer, 1986-87) De Silva, K.H.G.M.Item Studies on Atyidae (Crustacae:Decapoda:Caridae) of Sri Lanka. V. pH tolerance of three species of Caridina(University of Peradeniya. Peradeniya, 1986-87) De Silva, K.H.G.M.The pH tolerance of Caridina fernandoi, C. pristis and C. simoni was investigated by labaoratory experimentation. No significant difference between males and females in theirItem Food and feeding biology of the endemic carplets Barbus cumingi and B.nigrofasciatus (Oateichthyes, Cyprinidae) of Sri Lanka(1994) De Silva, K.H.G.M.; Somarathne, R.M.D.The food and feeding biology of B. cumingi and B. nigrofasciatus were studied in a small stream of the upper reaches of the river Mahaweli. Both species are herbivorous substratus feeders and their diets consist mainly of diatoms and detritus. Diatoms were the most abundant food item (50.1perc.) in the diet of B. nigrofasciatus but both diatoms (36.8perc.) and detritus (38.4perc.) were common in the diet of B. cumingi. Both species appear to avoid blue-green algea. The relative abundance of detritus and diatoms in the diet of both species varied from month to month and the importance of diatoms generally increase and that of detritus decreased with the increase of body size. The "intestinal" contents of B. cumingi contained a larger amount of diatoms in comparison to that of "stomach" contents, whereas in B. nigrofasciatus the amount of diatoms was low in the intestine. The relative gut length(RGL) of B. cumingi varied from 0.96 to 2.64 while that of B. nigrofasciatus varied from 0.89 to 2.54. These ranges agree well with reported RGL ranges for other herbivorous cyprinids. The RGL increased with increase in body size in both species as has been observed in other cyprinids.Item Caridina spp. (Crustacea:Decapoda:Atyidae) at suitable food organisms for the fry and fingerlings of food fish and ornamental fish(1984-85) De Silva, K.H.G.M.; De Silva, P.K.Item Some ecological aspects of the mangroves on the west coast of Sri Lanka(1984-85) De Silva, K.H.G.M.; Balasubramaniam, S.Mangrove formation (mangals) on the west coast are not extensive and, in most places, are limited to narrow strips bordering river mouths and estuaries. A clear ecological zonation is difficult to discern, except for a Rhizophora-Bruguiera zone at the edge of the water followed by a zone containing the other core species. The low level of tidal amplitude as well as persistend and long-term human interference are major factors that led to the limitation of mangroves to narrow strips and to the disappearence or non-establishment of proper ecological zonation. Floristic composition of wet zone mangroves is somewhat different from that of dry zone mangroves. This difference appears to be due to prevailling salinity differences, wet zone mangroves experiencing lower salinity conditions and dry zone mangroves experiencing higher salinity conditions. In each zone, there are riverine and estuarine mangroves. Four types of high salinity (dry zone) estuarine mangroves, viz, fringing, scrub, overwash, and basin, could be distinguished depeding on the geomorphic and flooding characteristics. Basin mangroves are not found on the west coast. MAngroves in Sri Lanka have been subjected to man's detrimental interference to a greater or lesser degree for a long time. In the north-east, mangroves have received relatively less interference, but, those on the west and south-west coasts have been highly interfered with, and in some cases, mangroves have virtually disappeared. Urgent conservation measures are requaired to save Sri Lankan mangrovesItem Reproductive ecology of two co-occuring, stream-dwelling, endemic carplets (Pisces, Cyprinidae) of Sri Lanka(University of Peradeniya. Peradeniya, 1994) De Silva, K.H.G.M.