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UPV Theses and Dissertations

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Committee Chair: search.filters.chair.Nievales, Marie Frances P.

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    Reproductive biology of coconut crab Birgus latro (LINNAEUS 1767) from Antique, Western Visayas, Philippines
    Alberca, Pavi Jewime O. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)
    The coconut crabs Birgus latro continue to decline globally and are now considered as an endangered species. In order to prevent further depletion of the species, much effort must be placed on implementing municipal ordinances such as seasonal closures and minimum legal size limits. This study aimed to monitor the breeding cycle of the Birgus latro from the islands of Sibolon and Maniquin. Antique. Philippines using macroscopic and microscopic techniques. A minimum of ten crabs were collected every month for six months (Aug. 2015 - Jan. 2016). The crab samples were examined based on the morphological and histological appearance of the gonads. The body weight, thoracic length (TL). cephalothoracic length, carapace width, pleonal expansion, gonad weight and hepatopancreas weight were measured. The gonadosomatic index (GSI), hepatosomatic index (HSI). pleonal expansion index (PEI) and gonad index (GI) were calculated. The results revealed two stages of development for both the male and female B. latro. The testicular stages were a) maturing stage - creamy white with the presence of spermatogonia, spermatids and spermatozoa; b) mature stage - creamy white and larger with the presence of the spermatozoa only. The ovarian stages were a) maturing stage - light yellow with the presence of oogonia, endogenous and exogenous vitellogenic oocytes and follicle cells: b) mature stage - reddish brown and larger with the presence of the fully mature oocytes. The smallest sexually mature crab for the male was 28 mm TL and for the female was 32 mm TL. The mature testes were observed all throughout sampling period, while the mature ovaries were only in August, September and October. The occurrence of the male B. latro was higher than the females. In males, the GSI and GI were directly proportional to the developmental stages. The HSI was inversely proportional. while the PEI showed no relationship. In females, the GSI. HSI. PEI and GI showed a direct relationship with the stages of development.
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    Behavior pattern of hatchery-produced sea cucumber Bohadschia marmorata (Jaeger, 1833) juveniles upon release
    Arcenas, Jascha S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)
    This study reports on the behavior of hatchery-reared Bohadschia marmorata juveniles upon release in two different microhabitat types within TINMR: a bare sand patch (TALISAY) and a seagrass vegetated area (BANAGO) during high tide and low tide. Percentage of burrowed juveniles, burying rates, traveled distances, speeds, and direction of movement were determined hourly over a 3-hr period. Results show that more than half of the juveniles released at the vegetated microhabitat displayed burrowing behavior at both tidal conditions. The mean percentage of burrowed individuals differed significantly with tides and their interaction with the microhabitat. Juveniles released at barren microhabitats yielded the highest burying rates (9 animals hr-1) and percentage of burrowed individuals. Coarse sand substrates with poor organic matter content induced mobility of Bohadschia marmorata. Results from the release experiments suggest that seagrass beds may be a potential release site for tropical species like Bohadschia marmorata.
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    Assessment of damage to mangroves in Taklong Island National Marine Reserve, Guimaras, Philippines: 10 years after the 2006 oil spill
    Amistas, Jhon Robert (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)
    Approximately 2 million liters of bunker C was spilled by M/T Solar I off the coast of southern Guimaras on August 11, 2006. This is the worst oil spill in the country to date that affected the mangroves within Taklong Island National Marine Reserve, Nueva Valencia, Guimaras. Rapid assessment of impacts on the mangroves was done one month after the spill and long-term monitoring was done from 2007-2014. This study was conducted to determine the mangrove status 10 years after the spill in terms of community structure. Specifically, it determined a) species composition, b) stand basal area, c) stand height, d) relative density, e) relative dominance, e) relative frequency, f) importance value, g) index of diversity, h) species evenness, i) density of seedling, saplings, and trees. In addition, leaf area was also determined as an indicator of the health conditions of the species present. The same five stations in earlier studies were used, namely Bagaman, Pototan, Taklong Island (oiled), Tandog and Taklong Island (unoiled), Nueva Valencia, and Guimaras. Results showed that the community structure showed an improvement, especially in stand, basal area, wilding, and tree density while no change in terms of species diversity due to the absence of new species. The leaf areas of mangroves in Bagatnan indicated some signs of stress but showed an improvement since 2006. In general, the oil-affected mangroves in TINMR have shown signs of recovery. However, it is recommended that additional monitoring activities be conducted.
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    Inhibition of bacterial Biofilm formation by selected wild Macrofungi from Miagao, Iloilo
    Anacita, Beatrice L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2023-07)
    Biofilms are complex bacterial communities with high-stress tolerance and antimicrobial resistance, posing a global health concern. Mushrooms are known for their bioactive compounds, including antimicrobial properties, and may offer a solution for inhibiting biofilm formation. This study investigates the biofilm inhibition activity of wild macrofungi collected in Miagao, Iloilo. Five basidiomycetous macrofungi—Panaeolus sp., Chlorophyllum hortense, Lentinus concavus, Hexagonia hydnoides, and Daedalea sp.—were characterized. Bacterial strains were treated with equal concentrations of ethanolic mycelial extracts from the macrofungi samples and evaluated for adherence and inhibition percentage using a microtiter plate assay at 37°C for 72 hours. The results showed strong inhibition (>50%) of all macrofungi extracts against S. aureus. Hexagonia hydnoides exhibited the highest inhibition against both S. aureus (84.3%) and E. coli (14.1%). Chlorophyllum hortense, Lentinus concavus, Daedalea sp., and Panaeolus sp. demonstrated 83.7%, 82.4%, 81.25%, and 80% inhibition of S. aureus biofilm formation, respectively. However, the inhibition observed with all extracts against E. coli was not statistically significant (all <15%). The significant findings, particularly in inhibiting S. aureus biofilm production, indicate the presence of biological activity in the tested macrofungal extracts. These findings suggest their potential usefulness in the search for antibiofilm treatments