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1989 - 198911990 - 19982
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Subject: Aquaculture × Author: KAU × End date: 2012 × Thesis Type: M.F.Sc ×
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    ThesisItemOpen Access
    Evaluation of different protein sources in the formulated feed for macrobrachium Rosenbergii (De Man) Juveniles
    (Department of Aquaculture, College of Fisheries,Panangad, 1989) Anilkumar, P; KAU; Thampy, D M
    The nutritional quality of five locally available sources of protein such as clam meat, squid waste, squilla shrimp head waste and silkworm pupae was evaluated in the feed for the giant freshwater prawn, macrobrachium rosenbergii, with a view to develop a feed which is cost effective. The feeds were prepared using these locally available ingredients along with groundnut oil cake, wheat bran,tapioca flour, supplevite (a commercially available vitamin- mineral mixture) and sardine oil and maize oil mixture. The protein sources tested were not found to be grossly deficient in their nutritional quality as good survival rates of over 90% were obtained when they were used as the main protein sources in the feed of juvenile prawn. Highest growth rate was obtained for clam and squid based diets, intermediate growth response with squilla and shrimp head based diets and the lowest growth among the various sources was given by silkworm pupae diet. Feed conversion efficiency was higher for clam and squid based diets, while intermediate feed efficiency was noted for squilla and shrimp head meal diets. Lowest feed efficiency was observed for silkworm pupae diet. Protein efficiency ratio showed a similar pattern. In the second experiment, substitution with carbohydrate for protein was found to be promising from an economic point of view. It was found that lowering of protein level from 35 to 30% could be achieved by increasing the carbohydrate level from 20 to 30% without affecting the growth , survival and feed efficiency. Similarly, protein level could be lowered from 30 to 25% by increasing carbohydrate by 10% from 20% level. This suggest that a 5% reduction of costly protein could be achieved by including 10% more of carbohydrate which will be able to reduce the cost of the feed with out sacrificing the nutritional quality of the formulated feed.
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    ThesisItemOpen Access
    Effect of eyestalk ablation on androgenic gland and male secondary sexual characters in Macrobrachium Idella (Hilgendorf)
    (Department of Aquaculture, College of Fisheries,Panangad, 1998) Sherine Sonia, Cubelio; KAU; Thampy, D M
    The present study in the prawn, Macrobrachium idella was taken up to find out morphotypic variation among the males, the endocrine basis for these variations and also to know the role if any, the eyestalk endocrines have, on the control of androgenic gland, which in turn is controlling the development of male primary and secondary sex characters. The study conducted to find the relationship between development of sex characters with that of androgenic gland conducted using 30 male prawns of different sizes has ShO\\-l1 that these sex characters are under the control of androgenic gland and have no relationship with that of the body size. Of the 30, 22 individuals were found to have a bodylength to cheliped length ratio below 1: 1.5, their androgenic gland and appendix masculina, not fully developed indicating that they are reproductively inactive. Remaining 8 individuals have a body length to cheliped length ratio above I: 1.5. They have well developed androgenic gland and appendix masculina showing that there is positive correlation between the biomass of androgenic gland and the cheliped length. An experiment conducted to find out the effect of unilateral eyestalk ablation on growth and development of primary and seconadry sexual characters as well as on the androgenic gland, had shown that destalking brings about a positive change in the development of androgenic gland and sex characters. The increase in the size of the androgenic gland and consequent hypertrophy of primary and secondary sexual characters brought about as a result of unilateral eyestalk ablation do indicate that the GlH, a hormone produced in the eyestalk has got an inhibitory effect on androgenic gland as well as on the growth of the prawn, which when removed by " destalking" , results in the enlargement of the androgenic gland and other sexual characters.
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    ThesisItemOpen Access
    Effect of eyestalk ablation on growth and reproduction of macrobrachium equidens (Dana)
    (Department of Aquaculture, College of Fisheries, Panangad, 1994) Bijulal, P S; KAU; Thampy, D M
    The objective of the present study is to evaluate the effect of eyestalk ablation on survival, growth, food conversion and reproduction of adult Macrobrachiumequidens. In the first experiment conducted for 35 days, unilateral eyestalk ablation, bilateral ablation and control treatments were employed at four level of salinities viz 5, 10, 15 and 20 ppt. Complete mortality in bilateral ablation and survival rates of 40.625 % and 68.75% for unilateral and control treatments were recorded at the end of the experiment, the values ranging significantly. The four salinity levels applied did not significantly affect survival. The difference in growth between ablated and unablatedtreatments was insignificant in terms of percentage gain, specific growth rate and average daily percentage gain in terms of length and weight. Salinity levels also showed insignificant difference in growth. Food conversion rate was significantly better in ablated treatment. The different salinity levels tried showed significant difference with regard to food conversion, being better at 20 ppt. In the second experiment conducted for 60 days on females, eyestalk ablation was found to enhance ovarian. In the second experiment conducted for 60 days on females, eyestalk ablation was found to enhance ovarian development in terms of the number of spawns per female. Fecundity, absolute fecundity, and incubation period were not significantly affected although a marginal increase in absolute fecundity could be observed . In the experiments conducted on males it was found that growth rate and cheliped development were significantly better in ablated ones. The number of spines in the appendix masculine, length and biomass of the androgenic gland and width of vas deference, did not show significant variation, although a marginal increase in the biomass of the androgenic gland and the number of spines in appendix masculine was observed in ablated treatment. The different eyestalk ablation experiments have shown that in females destalking does not stimulate growth but there is better response for reproduction, whereas in males there is better growth and only marginal response to reproduction.