UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

Undergraduate Theses

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13

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1994 - 199922000 - 20081

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Adviser: search.filters.advisor.Geduspan, Jane S.Degree: search.filters.degree.Bachelor of Science in Biology

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    A preliminary study on the freezing tolerance of milkfish (Chanos chanos, Forskal) embryos
    Buendia, Jeremiah C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-03)
    Milkfish embryos of blastula and C-shaped stages were tested for cryoprotectant toxicity using DMSO and glycerol at 10%, 12% and 15% concentrations. Survival and hatching as well as the effects of freezing were observed. Glycerol was more toxic than DMSO. Freezing at 4°C resulted in the decrease of hatching, and ice crystal formation killed the embryos during the process of freezing to -80°C. C-shaped embryos had a higher survival and hatching than the blastula stage embryos in the toxicity and cold shock tests.
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    A study on spawning induction of Imbaw Anodontia edentula (Linne, 1758)
    Bacaro, Teressa Mae D. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2008-03)
    The mud clam, Anodontia edentula, was induced to spawn using extract from ripe and developing gonads. Clams responded to the spawning stimulus by extension of the foot, swelling and extension of the mantle, swirling of the whole body, rapid opening and closing of the valves, ejecting of white material from the excurrent siphon, and subsequent contraction of the adductor muscles. Successful spawning of all individuals occurred with the use of gonad extract. Developing homogenized extract was not as effective in inducing the broodstock to spawn. Gametes were released through the excurrent siphon located at the posterior end.
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    Effect of sperm concentration on fertilization and the timing of early developmental stages of Imbaw, Anodontia edentula
    Arboleda, Erika A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-04)
    In this study, effect of sperm concentration to fertilization rate is investigated. Also, the timing of early developmental stages is done. Sperm concentration at seventy' is most effective although not significantly different. In the range used, effect of sperm concentration to fertilization rate is broad. The concentration of ten sperm per egg is least effective and significantly different from all the rest. In developmental stages, polar body extrusion is observed after ten minutes from fertilization. Two-cell and four-cell is formed within an hour. After two hours, eight-cell and sixteen-cell stage is noted. The larval stage trocophore is already present after the fifteenth hour. The straight-hinge veliger can be observed after twenty-four hours.