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UPV Theses and Dissertations

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Department: search.filters.department.College of Arts and SciencesKeyword: search.filters.keyword.Spawning

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    The effect of different levels of salinity on the spanning of ablated mudcrab Scylla serrata
    Bueno, Jesse L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-04)
    Four salinity treatments with salinity levels of 15 ppt, 25 ppt, 35 ppt and 45 ppt with six replicates per treatment were utilized to determine its effect on the spawning of sexually mature bilaterally ablated mud crab Scylla serrata. The crabs range in weight from 250 grams to 580 grams and carapace width from 12.5 cm. to 16.5 cm. The results of the study showed significant difference (P<0.05) in the number of days when spawning occurred. The shortest duration when spawning occurred was at 25 ppt salinity with a mean value of 9.5 days. This was followed by 35 ppt and 15 ppt salinities with mean values of 15.69 days and 19.83 days respectively. Highest number of days when spawning occurred was at 45 ppt salinity at 24 days. All crabs died 2-3 days after spawning.
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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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    Species composition and distribution of fish larvae in Lianga Bay, Surigao del Sur
    Acabado, Cristy S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2007-03)
    The species composition and distribution of ichthyoplankton in Lianga Bay, Surigao del Sur was investigated in June 2004. A total of 37 families were recorded from horizontal tows collected in 32 sampling stations. The most dominant larvae were Gobiidae and Pomacentridae, which comprised 20.4% and 16.0% of all larvae sampled, respectively. Overall larval density was 4.2 ind. 100 m-3 (n=32; sd=5.0), with highest concentrations in the inner portion of the bay particularly in the west and southwest portions. On the other hand, egg density (mean=0.9 eggs m-3; n=32; sd=0.9) showed highest concentration near the coastline but further from the central basal portion of the bay. Patches of high egg concentrations suggest that Lianga Bay may serve as spawning ground for some species.