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731.
The effects of body size on the food intake, growth and conversion efficiency of the freshwater prawn Palaemon lamarrei have been studied. In captivity, fed on a restricted diet of the muscles of the fish Gambusia affinis, moulting in these prawns occurred once in 18 ± 5 days at a temperature of 26 ± 1°C. The importance of these cast moults, contributing a sizable amount of organic matter to the detritus deposit of freshwater habitats has been indicated. In a log-log system, both food intake and growth per day, represented as a percentage of body weight, showed an inverse relationship to the body size. Animals in the size range of 600–800 mg exhibited the highest conversion efficiency. The present study indicates that these prawns can be successfully reared and grown under laboratory conditions. 相似文献
732.
The amelioration effect of balanced diet with supplementation of vitamin C against stress was evaluated in freshwater paddy field fish, Clarias batrachus, exposed to organophosphate insecticide, monocrotophos (MCP). Three groups of fishes, that is, (E0) Control, (E1) MCP (2.14 mg L?1) exposure and E2) Vitamin C, MCP (0.2 g kg?1 body weight + 2.144 mg L?1) were selected for the sublethal study. The effect of MCP on protein metabolism in physiological sensitive tissues, namely gills, kidney, liver and muscle of the fish has been determined. Stress on Clarias batrachus was evident that the total protein, amino acid and ammonia contents were decreased, and urea and glutamine levels were elevated in all tissues for 30 days. Similarly, the activities of protease, aminotransferases and phosphatases were elevated significantly in all the tissues during the same period. Fish fed with a diet supplemented by vitamin C (0.2 g kg?1 body weight) could significantly counter these effects. 相似文献
733.
The effect of deletion of individual water-soluble (thiamin, riboflavin, pyridoxine, cyanocobalamin, pantothenic acid, folic acid, niacin, biotin, choline, inositol and ascorbic acid) and fat-soluble vitamins (vitamins A, D, E and K) in semipurified diets on growth and survival of juvenile shrimp, Penaeus monodon , was studied in the laboratory for 8 weeks. Diets lacking riboflavin and vitamin K did not affect growth and survival of shrimp. However, deletion of inositol and choline in the diet resulted in poor growth. Maximum growth was observed in the control diet (C1) supplemented with all vitamins. Diets deficient in ascorbic acid, biotin, folic acid, niacin, thiamin and α-tocopherol resulted in poor appetite and poorer feed conversion efficiency. All treatments except the control (C1) resulted in histopathological changes in the digestive gland cells. Detachment or destruction of the epithelial cells was observed in all treatments lacking individual vitamins but more severely in the treatment without a vitamin supplement, followed by inositol, choline and ascorbic acid deficient diets. 相似文献
734.
The effects of different salinities (0, 2, 4, 6 and 10‰) on food intake, growth, food conversion, and body composition of the freshwater catfish Mystus vittatus (Bloch) were studied. Under a restricted feeding schedule daily intake of food was found to be salinity dependent. Fish reared in 10‰ consumed more Tubifex tubifex, converted less efficiently and displayed poor growth as compared to individuals reared in fresh water. Fish flesh production decreased from 483 g (fresh water) to 177 g (10‰ salinity) as the salinity was increased. Water content of the fish was found to decrease with increase in salinity, while maximum ash (25.56%) and fat (42.25%) were exhibited by fish reared in 10‰ salinity. 相似文献