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ThesisItem Open Access Conditions for oxygen-packed transportation of penaeus indicus seed(Department of Aquaculture, College of Fisheries, Panangad, 1994) Geetha Rani Mani, V; KAU; Jayasree Vadhyar, KThe effect of four levels of packing density, (200PL/1, 300PL/1, 400PL/1 and 500PL/1), three levels of salinity (20ppt, 25ppt and 30ppt) and two levels of temperature (30_+ 1°C and 23 + 2°C) on the oxygen consumption rate of Penaeus indicus post-larvae (PL20) was investigated in a closed type respirometer. The dissolved oxygen in the test chamber decreased with the oxygen consumption of the animals. Oxygen consumption was found to vary with ambient oxygen levels at the different packing densities. Among the three salinities, and two temperatures, the lowest rate of oxygen consumption was recorded at 25ppt and 23 +_ 2°C. The effect of these factors on the duration and survival of transportation of the shrimp seed in specially designed hard plastic containers fitted with facilities for oxygen packing under uniform pressure (0.2 Kg/cm2) showed that oxygen packing in hypothermal conditions could help in increasing duration and survival. Salinity of 20-25ppt was found to give longer duration of survival. With increase in packing density, there was considerable reduction in the duration and survival of transportation of the seed. Cannibalism was observed as the major cause of mortality and it could be reduced by lowering of temperature. 200PL/1 could be transported with 100% survival within 6.5-8.5h at ambient temperature of 30+- 1°C under the afore-mentioned type of oxygen-packing. By lowering the temperature to 23 +-_ 2°C it was possible to safely transport with 100% survival the same numbers for more than 20h. Corresponding duration at 500PL/1 with 100% survival was 1-1.5h at ambient temperature and 4-5h at lowered temperature. To reduce cannibalism at ambient temperatures, hollow plastic translucent habitat material was incorporated into the oxygen-packed jars. This experiment was conducted at 25ppt salinity at different packing densities of 200PL/1, 300PL/1, 400PL/1 and 500PL/1. Relatively longer duration and higher survival was observed only at higher packing densities of 400PL/1 and 500PL/1 with the introduction of the habitat material. Water quality parameters in the experimental jars were analysed initially and finally at 70% survival rate. The reduction in dissolved oxygen levels in the oxygen-packed jars was well above the lethal limits even at the highest packing density of 500PL/1 at 70% survival. The decrease in dissolved oxygen levels and increase in ammonia-N and free carbon dioxide, differed with the duration of packing, temperature and packing density.ThesisItem Open Access Effect of different dietary levels of lecithin on growth,survival,moulting and body phospholipid levels in Macrobachium Rosenbergii postlarvae(Department of Aquaculture, College of Fisheries, Panangad, 1996) Mahesh, S; KAU; Sebastian, M JThe effect of dietary levels of lecithin on growth, survival moulting, FCR and body phospholipid levels of early postlarval freshwater prawn macrobrachium rosen bergii was examined using semi-purified diets in a 56 day feeding experiment. Five casein-egg albumin based semi-purified diets incorporated with 0,2.5,5,7.5 and 10% of purified soy lecithin (60% phosphatidylcholine) were formulated and fed to prawns (ten numbers per treatment) with an initial mean weight of 0.05386g. In order to examine the influence of lecithin at different growth stages of postlarvae the assessment was made every fourteen days during the study period. The result showed that although the overall growth performance was not affected by dietary inclusion of lecithin, SGR% of the prawns fed with the diet containing 2.5% of lecithin showed a significant difference at P<0.01level during the first fourteen days of growth. Similarly the FCR also showed significant variation (P<0.01) between the diets tested in the first and second fortnights (14th and 28th day). In the first fortnight the diets (D1, D2 and D3) produced consistent FCR, while the diets supplemented with higher levels produced higher values. No significant differences (P<0.01) between treatments were detected with regard to survival rate, moulting frequency and body phospholipid levels of the prawns with the termination of the experiment. The prawns moulted once in every night days and no abnormalitied like exuvia entrapment were noticed in any of the experiment animals . Increment of body phospholipids with respect to levels of dietary lecithin suggests a possible replacement of body PL pool with that of dietary PL. The result of the study suggests that supplementation of lecithin at a level of 2.5% in the diet can accelerate growth and improve FCR during the early postlarval phase of Macrobrachium rosenbergii (ie, upto 4 weeks after larval settlement) beyond this, supplementation of lecithin is not needed in the diet. No other deficiency of excess symptoms was detected in the experimental prawns and it is found that lecithin is not responsible for Exuvia Entrapment Disease in Macrobrachium rosenbergii postlarvae.ThesisItem Open Access Detritus of plant origin as a food source for Penaeus indicua H. Milne Edwards(Department of Aquaculture, College of Fisheries, Panangad, 1992) Unnikrishnan, R; KAU; Thampy, D MThe objective of the present study was to evaluate the feasibility of using plant detritus as an exclusive food source for the juvenile of Penaeus indicus and also to find out the level of its in corporation in a standard diet for the prawn in place of animal protein sources. When four plant detritus were simultaneously presented to p.indicus juvenile of size 25-32 mm and 110-150 mg, they exhibited best preference for detritus from Rhizophora apiculata, followed by chromolaena odorta, Pistia stratiotes and paddy detritus. Two better preferred plant detritus sources viz. R.apiculata and C.odorata, were subjected to bulk digestion and the improvement in protein level by way of microbial growth during the process of decay was recorded. Since C.odorata showed a better protein level (Max.av.25.716%) on the fifteenth day than R.apiculata (Max.av.7.528%) on the twentieth day, C.odorata detritus was used for the next two feeding experiments: the first to find whether it could be used as exclusive protein source and the second to find the level at which this could be used to replace animal protein source in a standard diet for P.indicus. The first feeding experiment, for a period of 28 days, to evaluate the feasibility of using plant detritus as sole protein source revealed that an exclusively detritus based diet is not suitable for P.indicus juveniles. The detritus based diet produced lower survival, growth, protein sufficiency ratio, protein digestability and high food conservation ratio when compared to that of control diet prepared with clam meal. The second experiment done with eight diets for a period of 21 days revealed that plant detritus could be used for substituting upto a level of 50% of the animal protein source in a standard prawn diet, without producing any adverse effect on growth and survival. While, a diet containing 10% plant detritus fared even better than a diet which was totally devoid of detrital protein. The growth, food conversation ratio, protein efficiency, apparent digestibility and protein digestibility values obtained for various diets did not vary significantly upto a stage where 50% of the animal protein was substituted with detrital protein, beyond which the values declined. The best values were obtained for the diet FD2 and the lowest for the diet FD8.ThesisItem Open 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 MThe 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.ThesisItem Open Access Protein requirement of the postlarvae and juveniles of Macrobrachium rosenbergii (De Man)(Department of Aquaculture, College of Fisheries, Panangad, 1992) Sahadevan, P; KAU; Sebastian, M JThree sets of experiments were conducted with the postlarvae and juveniles of the giant freshwater prawn. Macrobrachiumrosenbergii (De Man). The first experiment was conducted to determine the quantitative protein requirement of the two life stages of the prawn using casein and amino acid based purified diets having graded levels (0, 10, 20, 30, 40 and 50%)of protein. Each experiment was conducted for 40 days and the effect of protein concentration on the survival, growth, food intake, food conversion efficiency, protein digestibility, nitrogen exeretion, nitrogen retension, body carcass composition, efficiency of protein utilization and oxygen – nitrogen ratio was studied. Among the different diets the one with 30% protein produced the best results in the postlarvae and juveniles of the prawn. Using second order polynomial regression analysis and differential calculus methods the protein requirement for maximum growth in the postlarvae and juveniles of the prawn was calculated as 34.5 and 28.5% respectively. In absolute terms these represent 787.9 and 529.0mg protein per 100g body weight of the prawn per day. The economic protein requirement of the postlarvae and juveniles was found to be 27.5 and 23.0% respectively. The maintenance protein requirement of the postlarvae and juveniles was determined to be 17.95 and 18.69mg protein per 100g body weight per day assuming an efficiency of utilization of protein very close to 100%. The metabolic faecal nitrogen excretion was found to be 198 and 151mg N per 100g body weight per day for the postlarvae and juveniles respectively. In the second set of experiments, short term (10 days each) studies were conducted to determine the efficiency of assimilation of certain locally available sources of protein by the postlarvae and juveniles of M. rosenbergii. These experiments were conducted also to help fix the levels of protein to be maintained in the third set of experiments. The protein sources evaluated were casein, prawn meat, clam meat, soybean, ground nut oil cake and black gram. The results of the study indicated that the apparent protein digestibility is not influenced by animal or plant origin of the ingredient. The third set of experiments was conducted to evaluate the effect of substitution of protein of animal origin with that of plant origin in the postlarvae and juveniles of M. rosenbergii. Each experiment was conducted for 40 days and on the basis of data on survival, growth, food intake, food conversion efficiency, protein digestibility, carcass composition, efficiency of protein utilization and oxygen – nitrogen ratio, substitution of 50 and 75% protein of animal origin with that of plant origin was found to result in no significant decline in the overall performance of the postlarvae and juveniles respectively of M. rosenbergii.ThesisItem Open Access Evaluation of supplementary feeds and optimum ration for Chanos chanos (Forskal) fry(Department of Aquaculture, College of Fisheries, Panangad, 1991) Elizabeth, Chrolin; KAU; Susheela, JoseThe present study was conducted in C. chanos fry,to evaluate the efficacy and keeping quality of supplementary feeds compounded from five different protein sources viz., fish meal ( FM ), squid meal (SQM), clam meal (CM), prawnhead waste meal (PHM) and soybean meal (SYM). All the feeds used in the study were isocalorific (3.13 - 3.33 Kcal/g) and isonitrogenous (39.78 - 40.44% crude protein). The quality of feed after four months of storage was satisfactory as there was not much variation in their nutrient contents. The FCR of fish fed on various supplementary feeds for 42 days were 1.74, 2.94, 3.65, 5.32 and 10.9 for CM, SQM, FM, SYM and PHM, Respectively. The PER, protein digestibility co-efficient and 0: N ratio indicate that protein from clam meal is better utilized for growth Purposes than those from others. The PER value ranged from 0.23 (PHM) to 1.45 (CM). The protein digestibility co-efficient, for CM, SQM, FM, SYM and PHM were 97.24,91,86, 86.56, 77.78 and 65.23%, respectively. The 0: N ratio was highest (10.769:1) for fish fed on CM. It seems that C. chanos fry digest lipid from animal protein sources better (digestibility values ranging from 84.17% (PHM) to 98.8% (CM)) than that from plant source SYM (47.49%).The biochemical composition of fish Showed maximum synthesis of protein and deposition of fat in fish fed on CM, followed by SQM, and the least in fish fed on PHM. The evaluation of supplementary feeds based on survival rate, gain in length and weight, and specific growth rate indicate the superior performance of animal protein sources (except prawn head waste meal) to plant source. The highest gain in growth was attained by fish fed on CM, followed by SQM and FM. Performance of fish fed on SYM was not satisfactory, while PHM was a poor feed for C. chanos fry. The optimum food ration of fry is at 5.2% of the body weight when fed with CM, twice a day, at 4-6 ppt salinity.ThesisItem Open 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 MThe 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.ThesisItem Open 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, CThe 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.ThesisItem Open Access Effect of eyestalk ablation on the rematuration of female macrobrachium rosenbergii (De Man) in captivity(Department of Aquaculture, College of Fisheries, Panangad, 2003) Vadher Kailashkumar Hirabhai; KAU; Aneykutty, JosephThe giant freshwater prawn, Macrobrachium rosenbergii is one of the commercially important spccces widely cultured throughout the tropics, subtropics and some parts of the temperate region. Non- availability of brood stock in sufficient numbers at appropriate time has been the greatest constraint for successful operations of prawn hatcheries. To avoid entire dependence on natural sources, development of brood stock of female prawns in captivity is essential. The objectives of the present study were to find out the role of eyestalk ablation on rematuration of spent female of M. rosenbergii in captive conditions and to study the histology of the ovary during rematuration of eyestalk ablated and unablated spent female of M. rosenbergii. In the rematuration experiment the effect of eyestalk ablation on moulting frequency, spawning frequency, larval hatch fecundity, incubation period, ovarian development and ovarian index of spent female of M. rosenbergii was evaluated for 60 days. The histology of ovary in M. rosenbergii during rematuration was also studied. The analysis of the result was done with student's t-test and paired t- test. A significant difference was observed in moulting frequency and spawning frequency of ablated and 'unablated spent female of M. rosenbergii. Larval hatch fecundity of ablated and unablated spent female of M. rosenbergii was not found to vary significantly. Significant difference was found in larval hatch fecundity after first time and second time hatching of both ablated and un ablated individuals. The incubation period was not found to vary significantly among ablated and unablated. However, slight reduction in incubation period was observed in ablated ones. Five histological stages of ovaries viz. previtellogenic stage, early vitellogenic, vitellogenic and late vitellogenic and matured oocytes were observed. In the histological sections of the ovaries, starting from spent ovary to the ripe ovary at weekly interval, similar type of oocyte development stages were observed in both ablated and unablated. IIowever, the size of largest oocyte in ablated was slightly higher than the size of oocyte in unablated at each week of development. It was observed in the present study that ovarian index of ablated spent female was higher than unablated at each week of development. The rematuration experiment has shown that eyestalk ablation significantly enhanced moulting frequency and spawning frequency but the effect was insignificant in terms of larval hatch fecundity and incubation period in spent female of M. rosenbergii. Insignificant increase in ovarian development and ovarian index were also observed in ablated spent female of M. rosenbergii.
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