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Undergraduate Theses

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

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Committee Member: search.filters.committeemember.Libutaque, JesusaDegree: search.filters.degree.Bachelor of Science in Biology

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    Community structure of riverine mangrove stand in Brgy. Talokgangan, Municipality of Banate, Iloilo Province
    Belaño, Keith Dominador L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2001-04)
    The community structure of riverine mangrove stand in Brgy. Talokgangan, Municipality of Banate, Iloilo was studied. Ten “true” mangrove species representing seven families were encountered in the “mangals” of Balandra creek community in Brgy. Talokgangan. They were Avicennia marina, Avicennia lanata and Avicennia alba representing Family Avicenniaceae; Rhizophora apiculata and Rhizophora mucronata under Family Rhizophoraceae; Sonneratia alba of the Family Sonneratiaceae; Excoecaria agallocha under Family Euphorbiaceae; Camptostemon philippinense of the Family Bombacaceae; one from the Family Meliaceae namely Xylocarpus granatum, and Family Palmae represented by Nypa fruticans. Stand Basal Area was computed highest in Station 1 with 10.22 m2/ha. Station 1 was also the densest among the four stations with a density value of 2533 trees/ha. In terms of data evaluated per zone, the landward zone has a Stand Basal Area of 10.87 m2/ha which is slightly higher than the middle and riverward zones. The middle zone, however, was found to be the densest with 1850 trees/ha. The most dominant station was Station 1 with the highest Index of Dominance of 0.3319, however, was found to be the least diverse station. The highest Index of Diversity was computed in Stations 2 and 3, with diversity indices of 0.8976 and 0.8989 respectively. Avicennia marina was found common in all stations and the most dominant, making it the most important mangrove species. They were found to occupy the whole site, growing abundantly in wide range of conditions from areas frequently inundated by tidal flow in Station 1 to the firmer muddy substratum in the back mangrove areas. Rhizophora apiculata and Rhizophora mucronata was observed to occupy waterlogged soil conditions. Excoecaria agaliocha tend to flourish in firmer muddy substratum in open sites, whereas, Xylocarpus granatum was observed to occupy zones where salinity is lowest in areas rarely affected by tidal flow. Sonneratia alba and Camptostemon philippinense tend to grow in zones directly inundated by tidal flow.
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    Taxonomy and distribution of holothurians in selected sites within Panabolon Island, Guimaras
    Bachoco, Raian Dennis (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2001-04)
    This study mainly deals with the taxonomy and distribution of sub-tidal holothurians in 2 selected sites based on the predominant substrate and vegetation characteristics, within Panabolon Island. Sampling was done during low tides in the months of March and April 2001. A total of seven species in five genera belonging to families Synaptidae, Holothuriidae and Stichopodidae were recorded from the study area. The family Holothuriidae is the most common (4 species) of the three families. Synapta maculata is the most abundant species (33.33%) followed by Holothuria atra (27.27%) and Holothuria scabra (21.21%). Highest species diversity was observed in the coralline area with strong water movement while-densities are highest in areas with seagrass beds
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    Diel feeding patterns of angelwing clam Pholas (Monothyra) orientales (Gmelin, 1970)
    Alojepan, Marbe Joy L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-04)
    Filtration rate of Pholas orientalis measured using the indirect suspension deletion method and monitored by direct algal cell counts. Phytoplankton Isochrysis galbana was used as food at an algal cell concentration of 2.5 x 103 cells ml ”'. Biological rhythms have been demonstrated in all animals and plants except bacteria. They control rhythmic patterns in behavior and physiology of a living organism. Biological rhythms, or oscillations, have a “period” that is measured from one arbitrary point or phase of the rhythm to the next occurrence of that phase. They are best demonstrated in a 24 h cycle or circadian cycle. There is a widely varying feeding activity in the 24h cycle of P. orientalis observed at a constant temperature of 27$C and hydrogen ion concentration of 35%o Like any other bivalves, P. orientalis has defined feeding periods equivalent to food uptake at 2400h-0300h. Such observation could be supported by a previous study by Corda stating that optimal feeding was obtained at total darkness. Periods of digestion occur shortly after the periods of feeding. P. orientalis when actively feeding were observed to have extended siphons, larger valve openings, and an inclination of 45. One primary external stimulus that affected filtration rate was the amount of light present. Biorhythms provide temporal information, such as the time of day or season of the year, which facilitates adaptation of the organism to internal or external environments.