Ceylon Journal of Science (Biological Sciences)
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Item The ecology of a montane grassland in Sri Lanka VII. biomass production(1983) Amarasinghe, L.Item Diel oviposition cycle of Aedes albopictus (Diptera:Culicidae) at Peradeniya, Sri Lanka(1984-85) Karunaratne, S.H.P.P.; Amarasinghe, F.P.The diel oviposition cycle in Aedes albopictus (Skuse) was investigated under natural conditions at a site at Peradeniya, Sri Lanka. The pattern of egg laying demontrated was essentially unimodal, most of the activity occurring between 1300-1900 hrs. with a sharp peak during the hour before sunset (1700-1800 hrs). Oviposition also occurred immediately after sunrise but the level of activity is considered too low to indicate evidence of bimodality in the cycle.Item Responses of freshwater animals to sodium cyanide solutions III. tadpoles of Rana temporaria(University of Peradeniya. Peradeniya, 1965) Costa, H.H.Experiments with tadpoles of Rana temporaria with sodium cyanide solutions gave generally similar results to those with fish and Gammarus. Tadpoles, however, are less sensitive than than fish but more sensitive than gammarus. The response limit for frog tadpoles is about 0.00001N. Changes of temperature, pH and dissoved oxygen had effects on their reactions similar to those seen with fishes and GammarusItem Responses of freshwater animals to sodium cyanide solutions II. Gammarus pulex(University of Peradeniya. Peradeniya, 1965) Costa, H.H.Experiments with Gammarus puler with cyanide solutions gave generally similar results to those given by experiments with fish. These animals however, appeared to be less sensitive than fish. The response limit for Gammarus, for sodium cyanide, is about 0.0001N. Addition of thiosulphate to sodium cyanide reduce the toxicity but unlike with fish, the reactions are accelerated. Increasing the temperature, increasing or decreasing the pH and lowering the oxygen content had effects on their reactions similar to those seen in fishesItem Responses of freshwater animals to sodium cyanide solutions. I. fish(University of Peradeniya. Peradeniya, 1965) Costa, H.H.The present work includes the results of several hundred experiments to test the reaction of fish to sodium cyanide solutions using an which is a modification of that used by Jones (1947b)