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Theses

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1997 - 19986
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Subject: Aquaculture × Author: KAU × End date: 1999 × Start date: 1997 ×
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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
    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
    Growth and survival of Penaeus monodon Fabricius juveniles fed on diet at different levels of replacement of clam meat with de-oiled silkworm pupae
    (Department of Aquaculture, College of Fisheries, Panangad, 1998) Sreeja Menon; KAU; Susheela Jose
    The present study was conducted to evaluate the feasibility of replacing clam meat either partially or completely with de-oiled silkworm pupae in the diet of the black tiger shrimp, Penaeus monodon juveniles. Proximate analysis of the ingredients used in the preparation of formulated pelleted feed showed that de-oiled silkworm pupae contained 57.2% crude protein, while clam meat contained 53.22% crude protein. Six test diets were prepared with different levels of inclusion of clam meal and de-oiled silkworm pupae; the other ingredients being groundnut oil cake, tapioca powder, starch, cholsterol, vitamins and minerals. Diet T! contained 100% clam meal and 0% de-oiled silkworm pupae, diet T2 80% clam meal and 20% de-oiled silkworm pupae, diet T3 60<% clam meal and 40% de-oiled silkworm pupae, diet T 4 40% clam meal and 60% de-oiled silkworm pupae, diet T, 20% clam meal and 80% de-oiled silkworm pupae and diet T6 0% clam meal and 100% de-oiled silkworm pupae. All the feeds were isonitrogenous with crude protein content ranging between 34.89% and 35% and isocaloric with caloric value ranging from 3.83 to 4.06 Kcal/g. Water stability levels of the pelletcd feeds were found to be satisfactory ranging from ~3.8% (T!) to 89.34% (T6) at the end of six hours. Penaeus monodon juveniles were reared for six weeks in experimental tanks. The water quality parameters were maintained well within the tolerance limits of P. monodon juveniles throughout the course of the study. The highest growth 141 (1.5282g) was recorded in shrimp juvenile~ fed with diet Tj , followed by diet T2 (1.4886g) and the lowest with diet T6 (0.7350g). Analysis of variance of the data showed that there is no significant difference (pzO.05) between treatments T, and T 2. No statistically significant- difference (PzO. 05) could be discerned in specific growth rate of shrimp juveniles of treatmentsT land T 2. The highest survival (93.33%) was obtained in P. monodon juveniles fed with diet T, and lowest (83.333%) with diets T, and T6. The food conversion ratios (FCR) obtained with different feeds range from 2.52 to 6.89. The lowest FCR was recorded with diet T, (2.52) followed by diet Tz (2.5466) and the lowest with diet T 6 (6.89). Statistically no significant difference (pzO.05) in FCRs of treatments T, and Tz was observed. Protein efficiency ratio was found to be highest in shrimp juveniles fed on diet T, (1.1398) followed by diet T2 (1.1255) and the lowest with diet T6 (0.4168). No statistically significant difference (pzO.05) was observed in protein efficiency ratios of treatment T land T 2. Productive protein value was found to be highest in shrimp juveniles fed on diet Tl (3.7917) followed by diet T2 (2.6149) and the lowest with diet T6 (0.3881).
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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.