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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/30

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    Effect of size on spawning of Imbaw, Anodontia edentula (Linnaeus, 1758)
    Cambel, Marianne P. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2008-04)
    The effect of shell size to spawning of imbaw, Anodontia edentula was examined. A total of 120 clams with shell length ranging from 34.90 to 68.20 mm were collected. Basing on shell length, 3 class sizes were used to group these clams, namely: < 45 mm, 45-50 mm, and > 50 mm. Thirty-five percent of the clams had shell length of < 45 mm, 21.7% in the range of 45-50 mm, and 43.3% had shell length of > 50 mm. Overall result showed that a high percentage of the clams in the range of 35 to 50 mm responded to spawning induction. Result showed that 41 (98%) of the clams in class size < 45 mm spawned. Twenty-six (100%) of the clams in 45-50 mm spawned and 31 (60%) spawned in class size > 50 mm. A mortality of 2 occurred among the broodstock and had shell lengths of > 50 mm. Among the clams induced to spawn, males predominated in the sample. Only 1 case of hermaphroditism was observed in < 45 mm and no females were observed to spawn. The only immature male in class size < 45 mm has a GSI value of 22.3. The mean GSI value of the 19 immature clams in class size > 50 mm was found to be 23.9 (±7.62).
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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.