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Subject: Fisheries × Author: KAU × End date: 1991 × Start date: 1991 ×
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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.
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    ThesisItemOpen Access
    Utilization of prawn waste as pig feed
    (Department of Animal Nutrition, College of Veterinary and Animal Sciences, Mannuthy, 1991) Syam, Mohan K M; KAU; Sivaraman, E
    An investigation was carried out to assess the feeding value of prawn waste as a partial or complete replacement of unsalted dried fish in the rations for growing – finishing pigs. Thirty – two Large White Yorkshire weanling pigs with an average body weight of 9.1 kg were distributed randomly and uniformly as far as possible to four groups (Groups 1, 11, 111 and IV) of eight animals each, with regard to age, sex and body weight and housed in pairs of the same sex. The four dietary treatments A, B, C and D were allotted to the pigs in the groups 1, 11, 111 and IV respectively. Of the total protein, 25 per cent in the diets A, B and C and 12.5 per cent in the diet D were provided as animal protein. Unsalted dried fish was used as animal protein source in the diets C and D. Diet C formed the control diet. In the diets A and B, 50 per cent and 100 per cent replacements respectively of animal protein from unsalted dried fish were made using dried prawn waste. All the animals were maintained on the respective diets with 18 per cent total protein upto an average live weight of 50 kg and with 14 per cent protein till they attained a body weight of 70 kg or 8 months of age, whichever was earlier, when they were slaughtered to study carcass characteristics.
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    ThesisItemOpen Access
    Breeding biology of Villorita cyprinoides (Gray) in relation to salinity gradients
    (Department of Fishery Biology, College of Fisheries, Panangad, 1991) Sudha, B Nair; KAU; Jose, T M
    The present study was undertaken to investigate the influence of salinity variations on the breeding biology of populations of black clam Villorita cyprinoides (Gray), inhibiting two different cological zones of the Vembanad Lake. Two stations with perennial clam beds, but differing greatly in salinity conditions were selected for the study. Station I, in the northern side of Thanneermukkam barrier, has more influx of sea water and Station II, in the southern side has low saline influx. Monthly collections of black clams and bottom and surface waters were made from May 1989 to June 1990. Major environmental parameters such as salinity, temperature, dissolved oxygen and pH of bottom and surface waters were estimated with a view to understand the circannual variations within and between the stations. Among these, salinity was found to be the most important parameter showing prominent variations. At Station I, the bottom salinity values ranged from 0.0 to 18.12%0 and in Station II from 0.0 to 2.12%0. Histological studies of the clams collected from the two stations revealed that animals inhabiting Station I, a predominantly brackish water zone, have a protracted, almost year round breeding season extending from September to June with peak spawning during March to June and coinciding with the peak salinity levels and temperature. At Station II, a predominantly freshwater zone, the clams have a short duration spawning season extending from March to June with peak spawning during Apirl and May, again coinciding with the peak salinity levels and temperature. It is also observed that there exists a positive correlation between the bottom salinity and gondal maturation and spawning. Size – frequency studies of the calms collected from the two stations revealed that at Station I, the clam fishery was dominated by small sized animals, when compared to Station II. This may be related to the differences observed in the extend of spawning activity between the population of the two stations, resulting in the divergent apportionment of energy resource for somatic growth versus reproduction.
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    ThesisItemOpen Access
    Effect of sedatives on penaeus monodon fabricus seed under oxygen packing for transportation
    (Department of Aquaculture, College of Fisheries, Panangad, 1991) Joshi, K; KAU; Jayasree Vadhyar, K
    The study was performed with the objective of selecting a sedative at a suitable dose and testing its effect along with other factors viz. packing density, salinity and temperature on the P.mondon seed under oxygen – packed transport conditions. The selection of a sedative at an appropriate dose, from those tried viz. chloral hydrate, MS-222 and tertiary butyl alcohol, was made by conducting statistically designed experiments on the survival of the treated and untreated prawn seed for 72 hours in open containers and on the metabolic activities of the treated and untreated prawn seed for 2 hours. The experiment to find out the effect of the selected sedative was carried out in specially designed hard plastic containers fitted with facilities fpr packing oxygen under uniform pressure. The experiment was conducted as an asymmetrical factorial experiment with 4 levels of packing density (200/1, 400/1, 600/1 and 800/1) and 2 levels of sedation (without and with sedation), salinity (25 ppt and 20ppt) and temperature (29+ 10C and 23 + 20C). Chloral hydrate was selected at a dose of 400 ppm for application on P.monodon post –larvae under oxygen – packed conditions. The application of chloral hydrate on the prawn seed under oxygen packing at the selected dose evidently showed a negative effect. A lower dose (300 ppm) than the selected dose, studied separately, also showed similar results under oxygen packing . An increase in packing density decreased the time of initial mortality and percentage survival. At packing densities of 200/1, 400/1, 600/1 and 800/1, the safe durations of transport (duration of 100% survival) were 7.5 h,5 h, 3.5h and 2.5 h respectively at ambient temperature of 29+ 10 C. In P.monodon seed transport the number of seed has been found as more important than their weight in deciding the survival. A high salinity of 25 ppt was found better than a lower salinity for P.monodon seed transport. Lowering of temperature of the packing medium, rather than applying sedatives or lowering of salinity, has been found as a suitable method for increasing the survival during oxygen – packed transport of P.mondon seed. At the lowered temperature of 23+ 20C significantly longer duration of 100% survival (15h at 200/1 and 5 h at 800/1) and better percentage survival at 24 hours (92.5% at 200/1 and 83.13% at 800/1) than at the ambient temperature could be observed.
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    ThesisItemOpen Access
    Studies on texture and collagen content of commercially important tropical fishes
    (Department of Processing Technology, College of Fisheries, Panangad, 1991) Femeena Hassan; KAU; Sajan George
    Stroma proteins refer to slightly soluble proteins which are obtained after removing water and salt, soluble proteins in the muscle. The main constituent of stroma protein is collagen. The role of collagen in contributing to the texture and gaping of fish fillets has been studied using six commercially important fish species of India VIZ. sardine (SardineIla lonqiceps) ,mackeral ( RastralIiger kanaqurta ) , tilapia ( Oreochromis mossambicus ) , common carp (Cyprinus carpio), tuna (Euthynnus affinis) and shark (Scoliodon sorrakowah). The texture of raw fish meat was found to be influenced by the content of collagen in fish muscle. A significant correlation (P > 0.05) was obtained between soluble, insoluble and total collagen contents, and toughness of raw meat, as determined by sensory evaluation and two types of texturometers. Significant correlation was also obtained between actomyosin content and toughness of raw meat, determined either by subjective or objective methods (P > 0.05), but not to the extent of soluble or total collagen. In the case of cooked meat , although a significant correlation (P> 0.05 ) was obtained between actomysin content and cooked meat toughness ,no such correlation could be established between collagen content and cooked meat toughness. Stroma proteins seem to be important in deciding the texture of raw meat, whereas, In the case, of cooked meat, myofibrillar proteins are probably involved. The gaping phenomenon was studied in frozen fillets stored for a period of three months. A slight increase in gaping was noticed during storage period. However, this was not found to be statistically significant. Further studies have to be carried out to get a clear cut idea about the influence of collagen on gaping phenomenon in frozen stored fish. The two types of texturometers fabricated, spring - operated and weight - operated, were found suitable for assessing the toughness of raw fish meat, but not. Cooked meat.