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UPV Theses and Dissertations

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    Comparison of the length-weight relationship between starved and fed Scylla tranquebarica crablets
    Arroyo. Ritchel B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    This study aimed to determine the length-weight as well as the width-weight relationships of the Scylla tranquebarica crablets when starved and fed during the intermolt and premolt stages. Molt stages were identified and then the crablets were subjected to feeding or starvation for 36 days. Regression analysis showed the length-weight relationship of the Scylla tranquebarica crablets, including carapace length, carapace width, and body weight when fed and starved. Regression lines for each category differed from one another. Results showed that the fed crablets in intermolt and premolt stages showed greater body weight gain per unit carapace length and carapace width. The intermolt fed gave the highest weight gain per unit length and unit width among the treatments. Equations for interconversions of length and weight and for length and width are reported for the premolt and intermolt stages when fed and starved.
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    A comparative study of the effects of supplementary feeding and artificial substrate on the production of milkfish fingerlings in brackishwater ponds
    Adeyemi, Frederick F. (University of the Philippines Visayas, 1983-03)
    The growth and survival of milkfish fry in response to supplementary feeding and artificial substrate were evaluated at stocking densities of 75 and 100 fry/m2 for a period of 56 days from August 21 to October 15, 1982. The study was conducted in eighteen 40m2 experimental nursery ponds of the University of the Philippines Brackishwater Aquaculture Centre, Leganes, Iloilo. A 3 x 2 factorial experiment in completely randomized design was used and six treatment combinations between level of inputs (no inputs, supplementary feeding or artificial substrate) and stocking density (75 or 100 fry/m2) were investigated with three replicates per treatment. The best fish growth was obtained in Treatment VI (100 fry/m2 with substrate) with mean final weight and length of 1.59 gm. and 5.36 cm. respectively while Treatment IV (100 fry/m2 without feeding or substrate) gave the poorest fish growth with mean final weight and length of 0.83 gm. and 4.60 cm. respectively. Differences in mean weight and length among treatments were, however, not statistically significant. Mean percentage survival was significantly higher at a stocking density of 75 fry/m2 (82.8%) than at 100 fry/m2 (64.1%) but supplementary feeding or artificial substrate ix did not show any statistically significant effect on survival. At either 75 or 100 fry/m2 stocking density, supplementary feeding gave a numerically higher percentage survival than artificial substrate. Economic analysis revealed that a stocking density of 75 fry/m2 without supplementary feeding or artificial substrate was the most profitable treatment with a return on investment of 39.2%. At a stocking density of 100 fry/ m2, supplementary feeding with rice bran was more profitable than the use of artificial substrate with returns on investment of 22.6% and 9.1% respectively.