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2005 - 20085
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Subject: Aquaculture × End date: 2009 × Start date: 2004 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Commercial probiotics in tank reared nursery phase of freshwater prawn,Macrobrachium rosenbergii (De man, 1879)
    (Department of Aquaculture, College of Fisheries, Panangad, 2005) Beryl, E B; KAU; Mohanakumaran Nair, C
    The efficacy of two commercial probiotics, Waves and Epicin on the growth and survival of M. rosenbergii PL and on the chemical and biological characteristics of water and soil were studied. The experimental set up consisted of fiberglass tanks of 70 l capacity with two treatments and a control, each with 5 replicates. Soil from a fishpond was filled to a height of 5 cm and water filled to a height of 25 cm. The post larvae were stocked @ 500 no/m2 and mild aeration provided. Commercial freshwater prawn feed starter 1 (Higashi) was given @ 100% of body weight. Analysis before the introduction of probiotics showed the presence of microorganisms such as E. coli, Salmonella, Hafnia alvei, Faecal Streptococci, Aeromonas caviae, A. sobria, A. hydrophila and Enterobacter aerogenus in the water and soil. Enterobacteria such as Enterobacter aerogenus, Hafnia alvei, Aeromonas sobria and A. hydrophila were present in the PL. The probiotics Waves and Epicin were added @ 0.5 ppm and 0.25 ppm respectively to the experimental tanks once in ten days and the microbiological observations and water quality parameters were studied once in 15 days. The introduction of the probiotics increased the growth and survival and reduced the F.C.R. of M. rosenbergii in nursery system. The species composition of the bacteria in the soil, water and body of the animal were not affected by treatment with probiotics, other than that the E. coli present originally and continued in the control was not detected in the tanks treated with probiotics. The T.P.C. was also less in the treatments compared to the control. Probiotics considerably reduced the level of NH3-N in culture tanks. Epicin was found to have reduced the NH3-N level effectively than the Waves.
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    ThesisItemOpen Access
    Cryopreservation of spermatozoa of critically endangered yellow catfish Horabagrus Nigricollaris (Pethiyagoda & Kottelat 1994)
    (Department of Aquaculture, College of Fisheries, Panangad, 2007) Rajani Vadthya; KAU; Dinesh, K
    In order to develop gene banking techniques aimed at conserving the critically endangered black collared yellow catfish of the Western Ghats, Horabagrus nigricollaris and popularize this species in the aquaculture scenario a study on cryopreservation of spermatozoa was undertaken. Freshly collected milt was observed for its characteristics. Well water was used to activate the milt in various stages of the experiment. There was no significant difference in motility of spermatozoa or percentage hatching from fresh and milt cryopreserved using 10% dimethyl sulfoxide (DMSO). Screening of four extenders (A, B, C and D) containing NaCl, KCl, CaCl2, NaHCO3, KH2PO4, MgSO4.7H2O, Na2H PO4 and Glucose at various proportions clearly indicated that the extender composition had significant effect on the percentage of motility, fertilization and hatching. Selected milt samples were preserved under cryogenic condition and utilized for experimental spawn production. The quality of milt samples was analyzed for the spermatocrit value, sperm density, pH, motility score and time: values obtained ranged from 57.8 to 59.8%; 16.5 x 109 to 20.9 x 109 spermatozoa/ ml of milt; 7.2 to 7.4; 4+ to 5+ (i.e. 80-100%) and 30 to 70 seconds respectively. The most promising combination was extender - A with 10% DMSO as the cryoprotectant. The ratio of milt and diluent was 1:4. Samples were equilibrated at 0°C ± 4°C on ice and vapourised over liquid nitrogen fumes for 10 minutes and finally stored in liquid nitrogen for three months. Stored milt samples were thawed and utilized to fertilize the eggs. Quick thawing procedure (27°C ± 2°C for 7 seconds) was followed. A French straw containing 0.5ml milt was found to be sufficient to fertilize 200 eggs approximately. Average fertilization % obtained was 30.3 ± 2.8 for extender- A against 35.8± 0.4 for the control. Mean hatching % obtained was 35.0 ± 4.7 for extender - A and 41.6± 4.4 for the control. No significant difference in fertilization success was found between cryopreserved sperm and untreated sperm from the same milt samples. Viable hatchlings were produced from milt that had been cryopreserved for three months indicating the feasibility of establishing a cryopreservation protocol to bank the genes and popularize the aquaculture of this critically endangered species. With the rapid global expansion of aquaculture, there is a need for year-round availability of larvae that could, to some extent, be met through cryopreservation of gametes.
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    ThesisItemOpen Access
    Utilization of water spinach Ipomoea aquatica leaf meal as protein source in the feed of Macrobrachium rosenbergii post larvae
    (Department of Aquaculture, College of Fisheries, Panangad, 2007) Sijimol, A P; KAU; Thresiamma James
    The present study aimed to find out the feasibility of using water spinach leaves as a low cost plant protein source and dietary evaluation of the formulated diet through growth trials employing post larvae of Macrobrachium rosenbergii, thus to determine the optimum level of substitution of spinach leaf meal. The experiment was done for a period of 60 days. A comparison has also been made between the diets having various levels of inclusion of water spinach leaf meal over the control diet without spinach leaf meal. Five isonitrogenous test diets T1 to T5 were prepared with 30% crude protein. The feed ingredients used were clam meat, Ipomoea aquatica leaf meal, wheat bran, ground nut oil cake, tapioca flour, vitamin mineral mixture and sunflower oil. The control diet T1 was prepared by using all ingredients mentioned above, without Ipomoea leaf meal. The test diets T2, T3, T4 and T5 were prepared by using all ingredients mentioned above and replacing clam meat with water spinach leaf meal at inclusion levels of 12 %, 24 % 36 % and 48 % respectively. Results showed better growth rates in prawn post larvae fed with diets (T2) containing 12% Ipomoea leaf meal. Among the test diets, T2 recorded highest growth rate (603.63 mg). Specific growth rate, food conversion ratio and protein efficiency ratio also showed better performance of prawn post larvae fed on test diet with 12% inclusion of spinach leaf meal. The highest SGR (3.67) and PER (2.99) were recorded in prawns fed on diet T2 and lowest SGR (2.68) and PER (1.48) were obtained with diet T5. The survival rate of post larval prawns were not found to be significantly influenced by the various test diets used and the survival ranged from 77.5% to 82.5%.
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    ThesisItemOpen Access
    Evaluation of spirulina fusiformis as a protein source in the diet of penaeus monodon fabricius
    (Department of Aquaculture, College of Fisheries,Panangad, 2008) Tank Ketan, Vallabhdas; KAU; Thresiamma, James
    The blue green alga Spirulina fusiformis has been accepted as an ideal food organism since it has a high protein content of 60-65 %, besides being rich in vitamins, minerals, fatty acids (gamma-linolenic acid (GLA)) and antioxidant pigments such as carotenoids. The present study is aimed at finding out the feasibility of using Spirulina fusiformis as a protein source in the diet for black tiger shrimp Penaeus monodon (Fabricius). Six isonitrogenous test diets T1 to T6 were prepared with 40% crude protein. Clam meat was replaced with Spirulina at an inclusion level of 5%, 10%, 20%, 30% and 40%, and the substitution effect was compared with a control diet in which clam meat was the sole source of protein. The study was conducted for a period of 60 days employing Penaeus monodon postlarvae (0.04 g avg. weight) with six treatments and four replications. The postlarvae were stocked at the rate of 10 numbers per tank. On completion of the experiment the specific growth rate, food conversion ratio and protein efficiency ratio were superior in shrimp postlarvae fed with the test diet containing 20% Spirulina. The diet T4 (20% Spirulina) led to significantly higher growth response (p>0.05) than in other diets. Further increase in the Spirulina inclusion levels significantly decreased the growth and feeding performance. The highest SGR (6.82%) and PER (1.67) were recorded with diet T4 and lowest SGR (4.16%) and PER (0.62) were obtained with the dietT6. The percentage survival was significantly higher (97.5%) in T3 (10% Spirulina) and T4 (20% Spirulina). The best FCR was recorded for 20% Spirulina (1.49). The results suggest that Spirulina fusiformis cannot serve as the sole protein source in the diet of Penaeus monodon postlarvae but can be effectively used as a supplementary protein source.
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    ThesisItemOpen Access
    Utilisation of cocoa pod husk as a feed ingredient for Labeo rohita (Hamilton) fingerlings
    (College of Fisheries, Panangad, 2007) Navya, R; KAU; Shyama, S
    A 70 day study was undertaken to evaluate the use of cocoa-pod husk meal as a dietary ingredient for rohu, Labeo rohita (Hamilton) fingerlings. Six iso-nitrogenous diets (30% crude protein) were formulated. The five test diets had cocoa pod husk meal incorporated at 5, 10, 15, 20 and 25% inclusion levels. A fish meal-based diet devoid of cocoa pod husk meal served as the control. Feeding was done at 5% once daily. The test diets were acceptable to the fish and gave positive feed consumption and growth. Optimum performance in terms of weight gain was achieved by fish fed a diet with 20% inclusion level of cocoa pod husk meal. However, FCE, fish weight gain and SGR showed a decline in fish fed the test diet, particularly so in the 25% cocoa pod husk meal diet. The reduced fish growth was caused by the high fibre content of cocoa husk which resulted in low protein digestibilities during the study. No direct toxic effect of theobromine and other purine alkaloids in cocoa products were reflected in the study, cocoa pod husk can thus be safely recommended as a feed ingredient in supplementary diets for Labeo rohita, up to an inclusion level of 20%.