UPV Theses and Dissertations
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Item Community structure of bivalve mollusc in seagrass meadows in Taklong Island National Marine Reserve (TINMR), Nueva Valencia, GuimarasBacelonia, Renevi A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)This study gives updated insights on bivalves composition and biomass structure. It characterized the community structure of Class Bivalvia in four seagrass sites in Taklong Island National Marine Reserve (TINMR), Guimaras. Bivalves species composition, diversity, abundance, density and mortality index were determined as well as seagrass cover and environmental factors. The Arcidae family was the most abundant among the live familes. Anadara inaequivalvis was the most widespread and numerous species in all sites. This species also recorded the highest density of 20 indiv/ 100m2 while Decatopecten radula, Pinctata sp., Lima sp., Fulvia subquadrata, Tellin modesta, Atrina pectina, Spondylus versicolor, Isognomon isognomum and Paphia undulata all got the lowest density of 1.41 indiv/ 100m2 Among all sites, Piagau had the highest biomass and the most number of individuals. There is positive correlation between species abundance and seagrass cover along with sediment type indicating that habitat structure is important in shaping the community structure of bivalves.Item Temporal variation in the subtidal macroinfaunal composition of a NaGISA seagrass bed in southern Guimaras, Philippines between 2015 and 2016Bacabac, Earl Jeroh I. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)Seagrass meadows are amongst the most abundant and diverse ecosystems when it comes to biodiversity but due to stress induced by natural and anthropogenic factors, a worldwide decline threatens the vital ecological functions of these habitats. Studying the infauna provides clues and information about the complexity of seagrass ecosystems and provides information that would facilitate better seagrass area management and associated conservation efforts. The NaGISA sampling protocol was conducted in Calaparan seagrass bed in TINMAR, Guimaras, Philippines between Sept. 2015 and 2016. Overall macrofaunal density was recorded at 21,954.80 ± 36,109.62 ind.m'2 with macrofaunal density higher in 2015 than in 2016 albeit, insignificant except for capitellid polychaetes. Community structure analysis also found similarity in dominance patterns in the subtidal zone with other soft-bottom macrofaunal studies in the Philippines with polychaetes, nematodes, and crustaceans as the respective dominant macrofaunal groups observed. Dominant polychaete families were also found to be cosmopolitan and opportunistic. Granulometric analysis characterized the sediment as pebble to medium sand with mid phi values ranging from -3.69 to 1.10 but poor sorting in all sampling points was observed. Cymodoceaceans dominated the subtidal zone in both years (Halodule pinnifolia in 2015; Cymodocea rotundata in 2016). Correlation analysis showed macrofaunal densities to have a significantly strong negative relationship with sorting index and percent gravel while a strong positive relationship with percent seagrass cover. The poor sediment sorting, coarse sediment character, and seagrass cover were the primary factors influencing the observed decrease in macrofaunal density but the decrease is considered normal for the variability of macrofauna in the area. A clearer picture of macrofaunal interactions would be provided with comparison to intertidal macrofauna of the area in the sampling years and data on additional factors that were not measured in the study.Item Spatial variations of Benthic meiofauna communities from Palompon Bay, Northern LeyteBalasa, Melvy June (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)Meiofauna play a significant role in maintaining ecological balance in marine ecosystems especially in the dynamics of the seagrass meadows. The meiofauna links the upper trophic level with detritus-feeding organisms. Only few studies have been conducted in the Philippines, while no studies have been. This study was conducted in Palompon, northern Leyte in November 2011, to determine the spatial distribution of meiobenthic fauna in the area and to compare community structure in terms of species composition, species density, and species diversity among five stations included in the survey. Twenty taxa were identified with nematodes being numerically dominant, followed by harpacticoid copepods. It also showed the highest mean abundance for the entire habitat type. The overall mean density was 194585.1528 ind. m2, with the highest population at station 4. And the lowest population was recorded at station 2. Soft bottom habitat showed the highest recorded mean density among the 5 stations, Harpacticoids mostly dominated sandy substrate while nematodes were widely distributed.Item Species composition and food preference of fishes in two seagrass beds in Taklong Island, GuimarasApostol, Archie E. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1997-08)Seagrass bed is known as one of the most important biological system that serves as nursery areas, resting and hiding place of small organisms and feeding ground for fishes. Investigations on population structure and composition of fishes have been done to monitor species diversity, abundance, and distribution in seagrass ecosystem. However, few studies have related food preference to community structure. This study aims to determine the species composition and food preference of fishes in Bagatnan and Kalirohan seagrass beds in Taklong Island, Guimaras. Once-a-month sampling in Taklong Island was conducted during the months of October, November, and December 1996. The collection of fishes was done using gill net. It was casted —50 meters from the shore and parallel to the shore during high tide and hauled during the next low tide. All gathered fishes were measured and preserved in 10% formalin. For stomach content analysis, stomachs of fishes were excised, preserved and brought to the laboratory for analysis. Contents were flushed out from the stomach, sorted and identified to major groups (as food items). Based on the results of the study,Siganus fuscecens, Scarus psittacus, and Dichistodus chrysopoecilus were the most abundant species of fish collected in Bagatnan and Kalirohan seagrass beds Kalirohan had a slightly higher species diversity and species richness value than Bagatnan. Most of the fishes caught were omnivores and this feeding mode was clearly reflected in the results of the stomach content analyses Also, the most abundant and common species (e.g. S. fuscecens & Dischistodus spp) had various food items on their stomach. Seagrass blades, algae, foraminiferans and other seagrass-associated organisms (e g. fishes, sipunculids, crustaceans and molluscs) were present in the stomach of many species. Of these, foraminiferans are the most frequently encountered among the food items. A few species fed on single item such as Synodus variegatus, Atherioromorus sp. and Amanses scopes which were found to feed exclusively on fish, algae and seagrass respectively. Although factors like type of fishing gear used and its mesh size and the time of sampling may have biased the kind and size of fish collected, it was clear that the extent of seagrass cover and availability of other food sources (algae and meio- & macrofauna) have influenced the abundance, species diversity & richness and the food consumed (and perhaps, also preferred) by the fish fauna.