Thumbnail Image

Theses

Browse

19913
Reset filters
Subject: Aquaculture × Author: KAU × End date: 1991 × Start date: 1991 × Type: Thesis × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    ThesisItemOpen 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, Jose
    The 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.
  • Thumbnail Image
    ThesisItemOpen Access
    Standardization of oxygen packing procedure of chanos chanos seed
    (Department of Aquaculture, College of Fisheries, Panangad., 1991) Mary Marget, M J; KAU; Jayasree Vadhyar, K
    The present study was aimed at finding out the optimum conditioning method of C.chanos seed before packing, their optimum packing density, the effect of salinity, pH and oxygen pressure on their packing and the feasibility of using a sedative, tertiary butyl alcohol and chitosan as an absorbent in removing toxic metabolites accumulated in the oxygen –packed containers. Specially designed air tight plastic containers were used for packing the seed. Of the seed packed after four treatments viz. control, congestion,, gut voiding and gut voiding plus congestion, the fourth treatment was the best with 3.25 fold increase in the duration of 100% survival compared to the control. From packing densities of 20,30,40 and 50 numbers per 50 ml water, a linear relationship between packing density in g/50 ml(X) and time of initial mortality in hours (Y) was established as Y=51.398-20.44X. No significant effect on the duration and survival of the seed was observed at different levels of salinity (0.ppt, 10ppt and 20pp), initial pH (6.5-7.5, 7.5-8.5 and 8.5-9.5) and oxygen pressure (oxygen at atmospheric pressure and at 0.2 kg/cm2 pressure). The use of tertiary butyl alcohol at 3.0 ppm and 3.5 ppm resulted in light and deep sedation of the seed respectively. It also increased the duration of 100% survival by 1.67 and 1.25 fold at the respective doses, compared to the control. The feasibility of using chitosan as an absorbent in oxygen packing of the seed was ruled out.
  • Thumbnail Image
    ThesisItemOpen Access
    Cannibalism in the tiger prawn Penaeus Monodon fabricius in nursery rearing phase
    (Department of Aquaculture, College of Fisheries, Panangad., 1991) Abdussamad, E M; KAU; Thampy, D M
    Factors influencing the rate of cannibalism in the post-larvae and Juveniles of Penaeus monodon, were investigated under laboratory conditions. Cannibalism was found to be positively density dependent, significantly suppressed by shelter and negatively correlated to food availability and feeding frequency. With the increase in population density there was an increase in the rate of cannibalism. Provision of different additional sub¬strates in the rearing tanks was found to help in reducing cannibalism. Of the various substrates tested, clam shells and black polythene raffia were found to be the best shelters suitable for reducing cannibalism and assuring high carrying capacity. Feeding frequency was found to have greatest influence on cannibalism, which decreased with increase in feeding frequency. In P. monodon post-larvae cannibalism is invariably associated with attack made on animals undergoing moulting and is independent on the size of the victim. A high rate of cannibalism was observed during the early post-larval phase and it progressively decreased towards the late post-larval stage and juvenile stage, may be due to the decreased moulting frequency and acclimation to new rearing conditions and artificial feed. Substantial variation in size and growth rate was observed among, individuals at all stocking densities. The marked difference in individual growth rate observed within the group could be due to the interaction of various intrinsic and extrinsic factors.