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2010 - 20162
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Subject: Aquaculture × End date: 2016 × Thesis Type: M.F.Sc ×
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    ThesisItemOpen Access
    STUDIES ON GROWTH AND SURVIVAL IN NURSERY REARING PHASE OF FINFISH SPECIES IN FLOATING NET CAGES FOR MARICULTURE
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2016-11) SURESH, GALIDEVAERA; CHAMUNDESWARI DEVI, B (MAJOR); RAVINDRA KUMAR REDDY, D; MADHAVAN, N
    The present studies were conducted at the closed bay near Suryalanka, Bapatla, Guntur district on “Studies on growth and survival in nursery rearing phase of finfish species in floating net cages for mariculture”. Total three (3) studies were conducted. The first study was on the effect of stocking density on growth and survival of milkfish, Chanos chanos in floating net cages in closed bay, Bapatla. Triplicate groups of milkfish with an average initial weight of 2.90±0.32 g were randomly stocked in floating net cages (1m×1m×2m) at 20, 40, 60 and 80 fish/m3 designated as D20, D40, D60 and D80 respectively. Milkfish in the cages were fed with 35% CP formulated diet at 10% of body weight twice daily. Sampling was done weekly. At the end of the stocking trail, growth in terms of body weight, weight gain, specific growth rate of fish were high in D40 than those in D20, D60 or D80. There was no significant difference in the survival rates of milkfish at different stocking densities. Total Feed Conversion Ratio was lower in D40 followed by D20, D60 and D80. The cages stocked with 40 fish/m3 have highest growth performance and 80 fish/m3 showed highest biomass performance. Water quality parameters were at optimum level during study period. Results suggest that 40 fish/m3 could be recommended for producing better quality milkfish fingerlings and 80 fish/m3 for highest number of seed production. Second study was conducted to study the effect of stocking density on growth and survival of seabass, Lates calcarifer in floating net cages in closed bay, Bapatla. Triplicate groups of seabass with an average initial weight of 1.29±0.12 g were randomly stocked in floating net cages (1m×1m×2m) at 20, 40, 60 and 80 fish/m3 designated as SD20, SD40, SD60 and SD80 respectively. Seabass in the cages were fed with 45% CP formulated diet at 10% of body weight twice daily. Sampling was done weekly. At the end of the stocking trail, growth in terms of body weight, weight gain, specific growth rate and survival rate of fish was high in SD20 than those in SD40, SD60 and SD80. Total Feed conversion ratio was lower in SD20 followed by SD40, SD60 and SD80. The cages stocked with 20 fish/m3 have highest growth performance and survival. 20 fish/m3 showed better survival percentage than SD40, SD60 and SD80. Water quality parameters were at optimum level during study period. Results suggest that 20 fish/m3 could be recommended for producing better quality seabass fingerlings and 80 fish/m3 for highest number of seed production. Another experiment was conducted to study the optimum crude protein for milkfish, Chanos chanos seed in floating net cages. Milkfish fry were obtained through natural seed collection. Rectangular floating net cages made of bamboo poles was provided inside with 1×1×2m hapas. Predatory net and bird net were provided. PVC drums filled with air were fixed to the net cage for floating. Milk fish with mean body weight of 2.81±0.07 g were stocked at the rate of 40 fish/m3 in each hapa in the rectangular cages. Triplicates were maintained for each treatment. Fish fry were fed with 5 artificial dry diets containing 12.5% (Control - C), 15% (T1), 25% (T2), 35% (T3) or 45% (T4) crude protein. The diets were fed at the rate of 10% of the biomass for a period of 63 days (9 weeks). Water quality parameters like D.O, pH, salinity, NH3, NO-2, NO-3 and temperature were estimated at weekly intervals and were within the optimum range for culture of milk fish. At the end of 63 days growth experiment, fishes fed on 35% (T3) crude protein feed exhibited highest growth and survival performance at 1% and 5% level of significance. The present study showed that milkfish seed reared in floating net cages in the closed bay performed best at 35% crude protein.
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    ThesisItemOpen Access
    EFFECT OF COTTONSEED MEAL BASED DIETS ON THE PERFORMANCE OF CULTIVABLE FISH
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-09) PAVAN KUMAR, B; CHAMUNDESWARI DEVI, B (MAJOR); RAVINDRA KUMAR REDDY, D; BALASUBRAMANIAN, A
    Fish nutrition has advanced dramatically in recent years with the development of new, balanced commercial diets that promote optimal fish growth and health. Feed accounts for a major part (30-70%) of the total operation cost of an average fish farm. Traditionally, animal protein sources, particularly fishmeal have been the major ingredient of aqua feeds. Fishmeal is one of the most expensive ingredients in formulated fish feeds. Due to increasing demand, decreasing supply and the high cost of fish meal, fish nutritionists have concentrated their efforts to find alternative protein sources to substitute fish meal in the diet of fish. Thus, cottonseed meal (CSM), a by-product of the cotton fibre and cottonseed oil industries, has been used to replace fish meal partially or totally in fish diets. The present studies were conducted on “Effect of cottonseed meal based diets on the performance of cultivable fish” at College of Fishery Science, Muthukur. Cottonseed meal was used in the diets at four different levels 5%, 10%, 15% or 20%. Control diet was prepared with soybean meal (SBM), groundnut cake (GNC) and deoiled rice bran (DOB). All the formulated diets were isonitrogenous with 30% crude protein. Proximate composition and mineral composition of diets were analyzed by AOAC (1995) methods. Each diet was fed to catla and rohu in triplicate aquaria twice daily at 5% average body weight of the fish for three months for determination of growth response and survivability. Fortnightly sampling was done for the estimation of the water quality parameters and growth parameters [growth, percentage of survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and condition factor (K)]. Specific growth rate (SGR) and Hepatosomatic index (HSI) were estimated at the end of the experiment. Histopathological studies on liver of experimental fishes were conducted at the end of the experiment. Fishes were analyzed for proximate and mineral composition at the beginning as well as at the end of the experiment Significant difference was observed in growth, FCR, PER and K in both rohu and catla. Mortality was observed in catla. However, no mortality was observed in survival of rohu. Inclusion levels of CSM at 15 or 20% resulted in histopathological changes in the liver of both rohu and catla. Carcass composition was observed to be better at CSM10 and CSM5 in rohu and catla respectively. Better growth performance was observed at 5% CSM level of inclusion in catla. However, no significant differences were observed in the growth, survival and condition factor at inclusion level of 5% and 10% CSM in catla. Better performance was observed at 10% CSM level in rohu. Hence, it can be recommended that CSM can be included at 10% level in the diets of catla and rohu. Further inclusion of CSM results in growth depression.