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1989 - 198911990 - 19944
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Author: KAU × End date: 1996 × 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
    Studies on certain aspect of the biology of the barracuda of Cochin region
    (Department of Fishery Biology, College of Fisheries, Panangad, 1992) Krishnadas, K J; KAU; Rajasekharan Nair, J
    A systematic redescription of the three species viz. SphyraenajelloCuv.,S.obtusata (Cuv. & Val.) andS. barracuda (Walbaum), available in the Cochin region has been done. The food and feeding habits, breeding biology, length – weight relationship and condition cycles of S. jello, the commercially most important species of the region, have been studied in detail. A total of 141 males (270 – 943 mm TL) and 64 females (322 – 770 mm TL) collected during Nov. ’88 to Oct. ’90 were subjected to various investigations like qualitative and quantitative assessment of stomach content, feeding intensity, prey – predator length relationship, feeding habits, quantification of maturity stages, size at first maturity, spawning season and spawning frequency, sex ratio, spawning potential, length – weight relationship and condition and relative condition cycles using standard methods. S. jello is found to be a typical predator and a predominant piscivore. The species mostly feeds on small pelagic and mid – water shoaling fishes like clupeids, anchovies, scads and silverbellies, occasionally consuming cephalopods. The total length of the prey rangfed from 18.68 to 31.43% of the predator length. The size at first maturity is found to be 360 mm for males and 370 mm for females (350 – 400 mm length class). The species exhibits a prolonged spawning season in the Cochin region, spanning from April – September/October with increased activity during June to September. Individuals of S.jello spawn more than once during this prolonged spawning season. Female dominance in the population was noticed during May to July coinciding with spawning activity. The absolute fecundity of recruit spawners of S. jello ranged between 82, 431 and 1, 63,533 9400 – 501 mm TL). The intensity of feeding was lower during the period of increased spawning activity and higher during post – spawning period. The length – weight relationship worked out for the species is log W = -4.2751 + 2.5848 log L, the relationship showing no significant difference between the sexes. The relative condition cycle closely followed the spawning cycle, the values being close to ‘1’. Condition factor calculated using eviscerated weight of fish provided an index of true well being of the fish.
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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.
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    ThesisItemOpen Access
    Extent of adoption of scientific practices in prawn farming
    (Department of Management Studies, College of Fisheries, Panangad, 1990) Sasikumar, P K; KAU; Pushkaran, P S
    This study was undertaken to probe into the present situation of prawn farming in Kerala. The study aimed at assessing the communication media used for the dissemination of scientific prawn farming practices, the communication media utilized by prawn farmers at awareness and adoption stages, extent of adoption of scientific practices, correlates of adoption behaviour and the reasons for non-adoption or partial adoption of scientific practices. The study was conducted in Ernakulam district among 100 prawn farmers randomly selected. The data were collected through personal interview using a structured and pre-tested interview schedule. Appropriate standard statistical tools were used for analysis and interpretation. The extent of adoption was measured using the adoption quotient formula. Twenty four characteristics of prawn farmers were tested to find their association with adoption behaviour. The socio-economic variables studied were age, education, experience , land possession training participation, institutional credit utilization and income from prawn farming. The situational characteristics included total farming area, area under selective stocking , salinity, distance from bar mouth, average depth at high tide, average depth at low tide and number of crops raised. Scientific orientation, economic motivation risk preference, marketing orientation, extent of awareness of scientific practices in prawn farming and rationality in decision making were the socio-psychological variables tested. The communication variables studied were utilization of personal localite sources, utilization of personal cosmopolite sources and utilization of mass media sources. The study revealed that the extension communication media were very extensively used for the dissemination of scientific prawn farming technology. The most important individual method employed was farm and home visits. Other methods frequently employed were lectures, film shows, group discussions, training programmes and demonstrations. The farmers utilized more of personal localite sources, followed by personal cosmopolite and mass media sources for awareness as well as adoption. The mean awareness index of prawn farmers was 64.00 with majority of the farmers falling under the category of medium awareness. The mean extent of adoption of scientific practices was worked out , and majority of the farmers came in the medium category based on extent of adoption. Of the 19 scientific practices selected for study, all the practices except ‘acclimation of seeds’, ‘maintenance of dissolved oxygen level in the pond’ ‘monitoring and control of PH, control of algal blooms and ‘need based control of disease and parasites’ were heard by over 50 percent of the respondents. Only three practices viz. strengthening of buds and deepening of channels, fixing or repairing of sluice gate, and stocking the pond with selected prawn seeds were heard by all the respondents. Only two practices namely ‘strengthening of bunds and deepening of channels’ and ‘fixing or repairing of sluice gate’ were found fully adopted by 50 or above 50 percent of respondents. Highest full adoption was observed for the practices ‘fixing or repairing of sluice gate’. There was no full adoptes for the practices ‘maintenance of dissolved oxygen level in the pond’ ‘need based water exchange’ and ‘need based control of disease and parasites’. Highest partial adoption was observed for the practice ‘need based water exchange’ followed by ‘removal of aquatic weeds’, supplementary feeding based on biomass’ and ‘strengthening of bunds’ and ‘deepening of channels’. The partial adopters of these practices were 99 percent , 92 percent, 57 percent and 49 percent respectively. Important reasons for non-adoption and partial adoption of the practices were lack of awareness, lack of knowledge and non-adoption of the practice ‘stocking the ponds with selected prawn seeds’. Among the 24 variables tested to find out association with extent of adoption, only nine showed significant influence on adoption behaviour. The characteristics of prawn farmers which were found significantly contributing to extent of adoption were training participation, land possession, institutional credit utilization, area under selective stocking, number of crops raised, extent of awareness of scientific practices in prawn farming, rationality in decision making, utilization of personal cosmopolite sources and utilization of mass media sources. Multiple regression model fitted with the above nine variables illustrated that these nine variables together explained 86.82 percent of variations in extent of adoption. Further, the step-wise regression analysis revealed that the best subset of variables in predicting the dependent variables were utilization of personal cosmopolite sources, utilization of mass media sources and area under selective stocking. These three variables together explained 86.48 percent of variations in adoptive behaviour. Of the nine variables subjected to path – analysis all the variables except awareness of scientific practices in prawn farming and rationality in decision making had positive path coefficients. The indirect influence of the variables on extent of adoption were mainly channeled through utilization of personal cosmopolite sources and area under selective stocking.
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    ThesisItemOpen Access
    Growth response of penaeus monodon fabricus to pelleted feeds of different protein sources
    (Department of Aquaculture, College of Fisheries, Panangad, 1991) Josekkutty, P A; KAU; Susheela, Jose
    The efficiency and keeping quality of the five pelleted feeds formulated from different protein sources viz. clarm meal, prawn meal, slaughter house waste meal, soybean meal, single protein (marine yeast) were tested with a view to develop a suitable supplementary feed for Penaeus monodon The feeds were isonitrogeneous , crude protein content ranged from 39.76 to 40.3%) and isocaloric (Caloric value between 3.34-3.72 K.cal/g). The quality of the feeds over a period of four months of storage remained good, eventhough a slight reduction in nutritive value has occurred. P. monodon juvenile were reared for 6 weeks in experimental tanks with different artificial feeds the highest growth and survival were recorded in those fed with diet based on animal protein sources. Among the feeds tested, the clam meal based diet was found to be superior followed by diet based on slaughter house waste meal. The diet based on marine yeast was found to give better performance than those based on prawn meal or soybean meal. The food conversion ratios obtained with different feeds ranged from 2.18 to 3.26. The lowest FCR was recorded in diet based on clam meal (2.18) and the highest (3.26) in diet based on marine yeast. Protein efficiency ratios and protein digestability values were found to be higher in prawns fed with diet based on clam meal followed by diet based on slaughter house waste meal. Significant variations in the biochemical composition of prawns fed with diet based on different protein sources were recorded. Significant variation in oxygen consumption, ammonia, excretion and O:N ratios were recorded in prawns reared on different protein based diets. Highest oxygen consumption rate and lowest ammonia excretion rate were observed for diets based on animal protein sources than plant or single cell protein source. Among the different diets tested, diet based on clam meal recorded highest oxygen consumption, lowest ammonia excretion and highest O:N ratio values. The optimum food ration for P.mondon juveniles was found to be at 6% of the body weight while maintenance and maximum rations were 1.8% and 15% respectively for clam meal based diet. Food consumption, growth and survival of P.monodon increased, as feeding frequency was raised, however these parameters increased only upto an increase of 3 meal/day and there after they showed a declining trend.