UPV Theses and Dissertations
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Item Gonadal maturation stages of pink-fingered vinegar crab, Episesarma chengtongense (Serene and SOH 1967), from Capiz, PhilippinesBallon, Shaira B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)Pink-fingered vinegar crab is a nocturnal, burrow-dwelling, and tree-climbing crab that feed on mangrove leaf litters and foliage. This crab is a growing fishery resource in the Philippines and plays an important role in the nutrient cycling in mangrove areas. To determine the reproductive biology of this species, a one-year study was conducted to monitor the gonadal maturation stages of the pink fingered crab from President Roxas, Capiz. Collection of samples was done every first week of the month from February 2015 to January 2016. The determination of the gonadal maturation stages was done through the visual examination of the gross morphology and microscopic examination of the histological characteristics of the male and female gonads. A total of 425 (263 females, 162 males) crabs were dissected. Five stages of ovarian maturation were identified based on visual examination of ovaries, namely Immature (Stage I) with translucent to white colored gonad; Developing (Stage II) with a yellow colored gonad; Ripe (Stage III) with orange colored gonad; Mature (Stage IV) with two substages, the Early mature (Substage A) with brown colored gonad and Late mature (Substage B) with dark brown colored gonad and; Spent (Stage V) with light brown colored gonad. Microscopic examination of the ovaries revealed that ovary in Stage I is characterized by the presence of germinative zone composed of oogonia and maturation zone composed of previtellogenic oocyte, surrounded by randomly distributed follicle cells. Ovary in Stage II is composed of few oogonia, previtellogenic cells, and few endogenous vitellogenic oocyte on the periphery of the ovarian lobe. Ovary in Stage III is composed of dominant exogenous vitellogenic oocyte located outer the few endogenous vitellogenic oocyte. Ovary in Stage IV-A is composed of nearly mature oocyte while in Stage IV-B is composed of mature oocyte. Ovary in Stage V is composed of all cell types, disarrayed in the entire ovarian lobe. Two stages of male gonadal maturation were identified namely Immature (Stage I) with translucent testes that is composed of spermatogonia and spermatocyte when histologically examined and Mature (Stage II) with white testes that is composed of small, darkly staining spermatids. Size of female crab samples ranged from 26 to 48.1 mm carapace width (CW) while male crabs ranges from 26 to 47 mm CW. The smallest ovigerous female has 29 mm CW and the smallest male with mature gonad has 26 mm CW. Body sizes of ovigerous females were from 29 to 42.3 mm CW. The greatest prevalence of ovigerous females was in the size range of 30 to 34 mm CW. The highest percentage of the mature stage (Stage II) in male was in the size range of 45 to 49 mm. For females, the peak egg bearing season was May (87%) and September (92%). On the other hand, male crabs with mature testes were consistently high (70 to 100%) in all months of the year. The results indicated that the months of May and September should be declared off season in the capture of female crabs ranging in size from 25 to 44 mm CW. Only big females in the size range of 44 to 49 mm CW could be harvested. Likewise, also male crabs in bigger size range of 45 to 49 mm CW could be harvested. This is necessary to protect and conserve the existing population of this crab.Item Determination of the fungal flora in the rearing water, eggs, larvae and post-larvae of Penaeus monodon in a large-scale hatchery systemBaes, Glanee F. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1995-03)The rearing water and homogenized. eggs, larvae, post-larvae of Penaeus monodon were taken front the large-scale hatchery system. These were counted, isolated and identified. Analysis was done by determining the mean, standard deviation and skewness of the data. The result showed that the skewness of the yeast and mold counts in the rearing water were 0.93 and 0.64, respectively 'while that in the homogenized samples were 0.92 and 1.09, respectively. These showed that the data were positively skewed, hence, fungi were greater in the early larval stages than in the later stages. The mean showed that yeast yielded greater counts as compared to the molds. Furthermore, rearing water have also higher fungal count than that of the homogenized prawns. The fungi identified were Aspergillus, Balanium, Bispora, Cladosporium and Phialomysis. In the study, the fungi identified were the normal mycoflora which did not adversely harm the prawn due to favorable hatchery conditions, there being no disease outbreak during the duration of the study.Item Taxonomy and distribution of holothurians in selected sites within Panabolon Island, GuimarasBachoco, 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 bedsItem The effect of different feeding schemes on mudcrab Scylla serrata larvae fed with Artemia salinaBachoco, Anabelle M. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1998-04)The study on the effect of different feeding schemes of mudcrab Scylla serrata fed with Artemia salina was conducted to identify the zoeal stage of S. serrata where an addition of Artemia to the diet results to higher survival, shorter intermoult duration, higher growth index, and shorter metamorphosis to the megalopa stage. All treatments were fed with Brachionus at a density of 20 ind./ml. Results showed that larvae fed with Artemia from day 0 had consistently high percent survival and this is significantly higher compared to other treatments. This was followed by larvae fed with Artemia at day 3 and at day 6. However, statistical analysis showed that there is no significant difference between the two treatments. Significantly low percent survival was obtained on larvae fed with Artemia at day 9. Results also showed that larvae fed with Artemia at day 0 metamorphosed to megalopa stage after 18 days and obtained the shortest average intermoult duration of 3.6 days and highest growth index of 5 6. This was followed by larvae fed with Artemia at day 3, day 6, and day 9. Artemia has high nutritive value which contributed to high survival, shorter intermoult period, high growth index and shorter metamorphosis period up to the megalopa stage.Item Floristic composition and diversity of mangroves in selected sites in the province of Antique, Panay Island, Philippines.Balinas, Lucelle V. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2006-03)Mangroves in the Philippines are in constant danger due to innumerable disturbances in the environment. The study endeavored to assess the floristic composition and diversity of the mangroves in the province of Antique through transect and ocular survey in the randomly selected sites throughout the province. Diversity in the region is high with the presence of 3 1 true mangrove species represented by 16 families and 14 genera. The species include Acanthus ebracteatus, A. ilicifolius, and A. volubilis from Family Acanthaceae, Avicennia alba, A. marina. A. officinalis, and A. rhumphiana from Family Avicenniaceae, Camptostemon philippinensis from Family Bombaceae, Lumnitzera littorea and Lumnitzera racemosa from Family Combretaceae, Excoecaria agallocha from Family Euphorbiaceae, Pemphis acidula from Family Lythraceae, Xylocarpus granatum and Xylocarpus moluccensis from Family Meliaceae, Aegiceras corniculatum and Aegiceras floridum from Family Myrsinaceae, Osbornia octodonta of Family Myrtaceae, Nypa fruticans of Family Palmae, Bruguieria cvlindrica. B. gymnorrhiza, and B. sexangula, Ceriops decandra, C. tagal, Rhizophora apiculata. R. mucronata and R. stylosa from Family Rhizophoraceae, Scyphiphora hydrophvllaceae from Family Rubiaceae, Sonneratia alba, S. caseolaris and S. ovata from Family Sonneratiaceae, and Heritiera littoralis from Family Sterculiaceae . The Shannon Index of Diversity used to determine the measure of diversity in the area is correlated with Pielou's Equitability Index for Evenness. The measures of indices showed that diversity and evenness of the mangal area in the province are directly related, with values of 0.73232 and 0.51163, respectively. Caluya showed the highest diversity index of 1.0132, which consisted of 28 species from 13 families and 15 genera, while Bugasong has a relatively low diversity of 0.0486, denoted by 6 species from 4 families and 4 genera. In general, the high variations in the geomorphology of coastal areas in Antique provided a wide range of substrata for colonization of mangroves that contributed to the high species diversity.Item 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.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 Molluscicidal activity of tabaco dust against the brackishwater pond snail Telescopium telescopium (Gastropoda: Potamididae)Azucena, Paulene C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)Telescopium telescopium, a molluscan potamidid snail thrives in the muddy substrates of brackishwater ponds in the Philippines. It occurs in considerable numbers but uncontrollable increases in its population poses serious threats to pond production. Tobacco dust is considered as a potential biomolluscicide that is able to control pond snail infestation. A short-term bioassay was conducted to know the effectiveness of tobacco dust as a molluscicide against T. telescopium by determining its median lethal concentration (LC50) after a period of 96 hours. Twenty-five telescope snails were subjected to varying concentrations of tobacco dust, from 0 to 1.0 kg/L at 0.2-kg increments. Three replicates were done for every treatment. Counting of dead snails was done after 48 and 96 hours of exposure. Snails exposed to varying concentrations of tobacco dust exhibited several defense mechanisms such as avoiding the toxic solution by crawling out of the area, closing their operculum and retracting their bodies toward their shell. Highest snail mortality was observed at the 1.0-kg/L treatment. After the 96-hr. exposure time, the concentration of tobacco dust that proves to be lethal to 50% of the snails was computed to be 0.5849 kg/L. Indeed, tobacco dust is an effective molluscicide against brackishwater pond snails, particularly T. telescopium.Item Acute toxicity of polysolve oil dispersant to Nile tilapia (Oreochromis niloticus Linn.) fryAtas, Bryan B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2011-03)Forty eight hour (48h) static bioassays were conducted to determine the toxicity of Polysolve oil dispersant to Nile tilapia (Oreochromis niloticus) fry. Median lethal concentrations (LC50) were 1.03, 0.79, 0.70, 0.45, and 0.39% for 24, 30, 42, and 48h, respectively. Polysolve is highly toxic to Nile tilapia fry at low concentrations. Results showed increasing toxicity over increasing length of exposure. It is therefore recommended that Polysolve must not be used in oil spill response. Sublethal effects of the dispersant on the fry include decreased activity and impaired responsesItem Comparison of the length-weight relationship between starved and fed Scylla tranquebarica crabletsArroyo. Ritchel B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)This study aimed to determine the length-weight as well as the width-weight relationships of the Scylla tranquebarica crablets when starved and fed during the intermolt and premolt stages. Molt stages were identified and then the crablets were subjected to feeding or starvation for 36 days. Regression analysis showed the length-weight relationship of the Scylla tranquebarica crablets, including carapace length, carapace width, and body weight when fed and starved. Regression lines for each category differed from one another. Results showed that the fed crablets in intermolt and premolt stages showed greater body weight gain per unit carapace length and carapace width. The intermolt fed gave the highest weight gain per unit length and unit width among the treatments. Equations for interconversions of length and weight and for length and width are reported for the premolt and intermolt stages when fed and starved.