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Subject: Aquaculture × Author: KAU × End date: 1997 × Start date: 1997 × Type: Thesis ×
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    ThesisItemOpen Access
    Evaluation of growth in Penaeus Monodon Fabricius by incorporation of selected nonhormonal growth promoters in the diet
    (Department of Aquaculture, College of Fisheries,Panangad, 1997) Vinodh, M P; KAU; Susheela, Jose
    The effect of three growth promoters viz. Chitin, chitosan and glucosamine each at three levels (0.25, 0.5 and 1g per 100g diet) were evaluated in P.monodon early juvenile for a period of 70 days. The three growth promoters at three level were tested with 3 replicates for each treatment. The growth promoters were incorporated into a soyflour clam meal based practical diet containing 40% protein and fed to the shrimps adlibitum. The results showed that the overall growth was not affected by dietary inclusion of chitin though the growth rate at 0.25g chitin per 100g diet was comparatively better than that of the control diet. Chitin does not seem to have any effect on specific growth rate of the juveniles although incorporation at 0.25g/100g diet improved the food conversion of the animal significantly over the control. Percentage survival values were also not significant at any level of incorporation. It does not seem to improve protein efficiency ratio and productive protein value too. Incorporation of chitosan at 0.25 and 0.5g/100g diet significantly improved the weight gain, specific growth rate, food conversion ratio, protein efficiency ratio and productive protein value. However inclusion of chitosan at 1g/100g diet did not have any effect on growth though it significantly improved food conversion ratio, protein efficiency ratio and productive protein value. None of these treatments had any effect on survival of the animal. Incorporation of glucosamine into the diet at 0.25g/100g diet was found to be the most efficient amongst the different treatments as evidenced by various growth parameters. It was significantly different from all other treatments in terms of growth, productive protein value and protein efficiency ratio. However it was not significantly different from glucosamine incorporation at 0.5g/100g diet in terms of specific growth rate and food conversion ratio. Enhancement of glucosamine level to 1g/100g diet was found to give poor result compared to the control. The survival rate of shrimps were not significantly different among the treatments. Hence in the present study, glucosamine was found to be superior to chitin and chitosan as a growth promoter and the optimum level was identified as 0.25g/100g diet for P.monodon juveniles
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    ThesisItemOpen Access
    Effect of different diets on growth and survival of angel fish Pterophyllum scalare (Lichtenstein) fry
    (Department of Aquaculture, College of Fisheries, Panangad, 1997) Neelakanteswar, A; KAU; Mathew, P M
    The effect of different diets on the growth and survival of Angel fish, Pterophyllum sealare (Lichtenstein) larvae was studied. One day old free swimming hatchlings were used in the study for a period of 30 days. The different diets used were Artemia nauplii, Moina micrura, artificial diet, Artemia nauplii + Moina micrura and Artemia nauplii + artificial diet, with four replicates for each treatment. The experiment was repeated twice in order todetermine the consistency of the result. The results showed that the growth of larvae, in terms of gain in length and weight and specific growth rate, was maximum with the mixed diet of live foods. The differences in growth between artificial diet and mixed diet of Artemia nauplii + artificial diet were not consistent. No significant difference was found in the survival rate of larvae fed different diets. O:N ratios showed that the nutritional state of the larvae fed artificial diet was more or less similar to that fed mixed diet of Artemia nauplii + artificial diet, which in turn was comparable with that fed live foods. Thus, the artificial diet has been found to be an effective replacement diet in the larval rearing of Angel fish.
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    ThesisItemOpen Access
    Differential growth in the giant freshwater prawn Macrobrachium rosenbergii (De Man) during nursery rearing phase
    (Department of Aquaculture, College of Fisheries, Panangad, 1997) Mainuddin, Ahmed; KAU; Thampy, D M
    The present study was conducted on freshwater prawn Macrobrachiumrosenbergii (De Man) to find the effect of stocking density and provision of additional substrates in rearing tanks, on differential growth among different size groups of juveniles during early growth phase. The first experiment conducted with various stocking densities ranging from 25 to 800 nos/m2 had revealed that the differential growth and the average size of the post larvae were inversely proportional to the stocking density; however the total biomass production was directly related to the stocking density. The survival rate was not much affected by variation in the stocking density, being almost uniform (87 – 100%) among various treatments. The second experiment has shown that provision of additional substrates could not help to reduce differential growth, rather it enhanced it. However it helped to enhance the average growth, total biomass production and the survival rate. The size grading of juveniles after an initial nursery rearing period of 35 days, into four groups such as small, medium, large and a recombined control group and growing them separately for another 35 days has revealed that the size grading helped in reducing the differential growth and increasing the total biomass production, but could not help to increase the survival rate. It was found that the total biomass production in large size group was about four times higher than that of the small size group and about two times than that of the control group, indicating that growing M. rosenbergii juveniles in grow out systems after size grading and discarding the smaller size group, will be advantageous for increasing production. The male secondary sex character, the appendix masculine was found to appear after 154 days of metamorphosis, when the prawn had reached a size of 6.2 cm and 1.75 g. An allometric pattern of growth was observed in case of appendix masculine wherein a higher ratio of 1:1.34 was recorded in comparison to 1:1.14 of that of the endopod of the second pleopod, in the subsequent moult.
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    ThesisItemOpen Access
    Cold anaesthetization and live storage of Penaeus monodon Fabricius for transportation in chilled saw dust
    (Department of Aquaculture, College of Fisheries, Panangad, 1997) Salin, K R; KAU; Jayasree Vadhyar, K
    With a view to standardizing the technology of cold –anesthetization and live storage of adult penaeus monodon in chilled saw dust, three cooling rates of 1.38 + 160C/h within 8 hours (slow cooling rate) 2.76 + 0.320C /h within 4 hours (moderate cooling rate), and 5.52 + 0.640C/h within 2 hours (fast cooling rate) were tested to cold – anesthetize farm raised P.monodon (22.25g) at 15ppt salinity, from 250C to 14+ 10C (fixed on the basis of a pilot study) in plastic net boxes kept in a refrigerated chilling tank of 40 litre capacity, provided with aeration. The cold-anaesthetized shrimps at each cooling rate were packed separately in between two layers (about 3cm thick) of saw dust with 10% moisture and chilled previously at 2-30C, in specially prepared card board boxes (33x22x9cm) lined inside with 12 mm thick Styrofoam sheet. The boxes were kept inside a chilled storage cabinet and maintained at 14 + 10C for a duration of 16-36 hours, and the survival of the shrimps observed at four hourly intervals. The temperature was monitored using a six channel, digital, continuous freezer temperature monitor with a precision of 0.10C. The shrimps cold-anaesthetized at each cooling rate and live stored for each duration were revitalized in aerated circular fibre glass tanks of 80 litre capacity, half-filled with brackish water of salinity 15ppt, and temperature 200 C, which was raised @ 2.70C/h to the ambient temperature of 280C, within 3 hours. The shrimps which showed abnormal behavioural patterns by rolling over into their sides, and remained immobilized upon cold anaesthetization, recovered to active movements after revitalization. Although 100% survival of the packed shrimps was obtained for maximum durations of 24, 20 and 16 hours at the slow, moderate and fast cooling rates respectively, the corresponding statistically valid safe durations for obtaining 100% survival were computed to be 22.9 + 1.09, 19.1 + 0.4 and 14.62 + 1.13 hours, using probit analysis. However, for practical purposes, the durations for obtaining 95% survival were determined as 28.18 + 0.54, 25.7 + 0.54 and 21.88 + 0.71 hours for the slow, moderate and fast cooling rates respectively. Analysis of variance of the percentage survival showed significant difference (P<0.005) among the three cooling rates tested, while pairwise comparison revealed that the slow and moderate cooling rates were identical. This suggested that the moderate cooling rate which took only half the time for cold –anaesthetization of shrimp compared to the slow cooling rate can be considered the optimum, though the choice of the different cooling rates depends on the duration of storage desired. The difference in weight before cold anaesthetization and after revitalization of the live shrimp was studied at 12 and 24 hours of live storage at the three cooling rates, separately which indicated a loss of weight (1.49-8.83%) varying with the cooling rates and durations . However, this was not found to be statistically significant among the cooling rates and durations tested. Sensory evaluation of the cold – treated shrimps was conducted to study the effect of cold-anesthitization and live storage on their appearance and meat quality, at the three cooling rates after 12 and 24 hours of live storage, talking untreated shrimp as control. The body colour of the shrimps turned dark brown and the tips and margins of the pleopods and peraeopods became reddish. There was significant difference (P<0.05) in general appearance, and the colour and flavor of the meat between cold treated and untreated shrimps. However, the texture and odour /aroma of the raw/ cooked meat remained unaffected by cold – treatment. The effect of different cooling rates and the durations tested on the sensory quality of shrimp meat was not significant.