Undergraduate Theses
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Item Abundance, composition and vertical distribution of calanoid copepods in Central Sulu seaBurgos, Lora A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)Calanoid copepods are dominant component of the copepod community, which in turn highlights their influence on the overall zooplankton assemblage of the water column. Studying their abundance and distribution, is important on understanding their role in the dynamics of commercially important organism like the fish. Calanoid samples in study, were part of the zooplankton samples taken during the Joint PhilEx oceanographic cruise on board RAZ Melville in December 2007 in the Central Sulu Sea from MOCNESS station 29. Calanoid abundance, composition and distribution were investigated. Fifteen (15) calanoid families were identified all throughout the water column (0 - 400 m). The calanoid assemblage was dominated by 27 % Eucalanidae, 12 % Rhincalanidae, Scolecitrichidae with 7 % and other families contributing to roughly 19 % of the total. The water column was divided into 2 distinct depth cluster based on species distributions; (1) layers above thermocline (0 - 150m) and (2) deeper layers (200 - 400m). Furthermore, upper layers were characterized by distinctive calanoid family assemblage which includes; Calanidae, Euchaetidae, Eucalanidae, Candaciidae, Rhincalanidae, and Temoridae. While deeper layers, calanoid families includes; Metridinidae, Scolecitrichidae, Rhincalanidae, and Euchaetidae. ANOSIM results showed significant differences between these depth clusters, with global R = 0.81 and p = 0.01. These appear to be highly related to the thermocline in both stations, where typically higher upper-layer primary productivity can support dense communities of zooplankton.Item A preliminary study on the freezing tolerance of milkfish (Chanos chanos, Forskal) embryosBuendia, Jeremiah C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-03)Milkfish embryos of blastula and C-shaped stages were tested for cryoprotectant toxicity using DMSO and glycerol at 10%, 12% and 15% concentrations. Survival and hatching as well as the effects of freezing were observed. Glycerol was more toxic than DMSO. Freezing at 4°C resulted in the decrease of hatching, and ice crystal formation killed the embryos during the process of freezing to -80°C. C-shaped embryos had a higher survival and hatching than the blastula stage embryos in the toxicity and cold shock tests.Item The effect of different levels of salinity on the spanning of ablated mudcrab Scylla serrataBueno, Jesse L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-04)Four salinity treatments with salinity levels of 15 ppt, 25 ppt, 35 ppt and 45 ppt with six replicates per treatment were utilized to determine its effect on the spawning of sexually mature bilaterally ablated mud crab Scylla serrata. The crabs range in weight from 250 grams to 580 grams and carapace width from 12.5 cm. to 16.5 cm. The results of the study showed significant difference (P<0.05) in the number of days when spawning occurred. The shortest duration when spawning occurred was at 25 ppt salinity with a mean value of 9.5 days. This was followed by 35 ppt and 15 ppt salinities with mean values of 15.69 days and 19.83 days respectively. Highest number of days when spawning occurred was at 45 ppt salinity at 24 days. All crabs died 2-3 days after spawning.Item A quantitative and qualitative analyses of phytoplankton in Lamentao, Barotac Nuevo, IloiloBoglosa, Jescel B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2000-03)The study was conducted to identify the different genera of phytoplankton in Lamentao, Barotac Nuevo, to determine the distribution and composition of phytoplankton both near shore and offshore and to determine the physico-chemical characteristics in both sampling sites. The samples were obtained near shore (10m) and offshore (15m) for 10 minutes. Towing was done at 12 noon for 200 m. Sampling was done once a month for three consecutive months starting October to December. Each sample was allowed to stand for at least 24 hours. Then these were decanted to have a concentrated sample. Then 1ml sample was introduced in a sedge wick counting chamber for identification and counting under the microscope. The study gave the following findings: There are 32 genera identified in the surface water of Lamentao. Offshore has a higher abundance than the near shore. There are some genera that significantly differ in 2 sampling area shown by the t-test. Density offshore were generally significantly higher than density nearshore. Relative abundance, Leucosolenia sp. and Rhizosolenia sp. have the higher one. There is a higher diversity in off shore than in near shore. Most of the genera is present in both sites and month as shown by the index of similarity.Item Embryonic development and hatching rate of grouper (Epinephelus suillus) eggs incubated at different stocking densitiesBofill, Aileen B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1992-04)Fertilized eggs of the grouper Epinephelus suillus were obtained from natural spawning of broodstock reared in a 50—t concrete tank at the Aquaculture Department of the Southeast Asian Fisheries Development Center, Tigbauan, Iloilo. The development of eggs incubated at three different stocking densities (50, 1OO, and 150 eggs/1) were monitored. Hatching rates in the different treatments were also determined. Fertilized eggs were floating, non—adhesive, transparent, and spherical in shape with a mean diameter range of 0.83 — 0.84 mm. The yolk was colorless, transparent, and possessed a single oil globule of 0.22 mm in diameter. The eggs have developed into the 2—cell stage 45 min after stocking. Eggs incubated at 1OO eggs/1 hatched 24 h after stocking, while hatching occurred after 27 h and 5 min at 50 eggs/1. No hatching was observed at 150 eggs/1 stocking density even after 28 h post—stocking. Water temperature and salinity during the experiment were 27 ° C and IB ppt, respectively.Item Meiofaunal assemblages in the mangrove habitat in Taklong Island, Nueva Valencia, GuimarasBocoran, Mary Grace G. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-03)Meiofauna are metazoans that can pass through a sieve with a mesh of 0.5mm but retained in a mesh of 0.063mm sieve. These organism are interesting to benthic scientist due to its capacity to determine the extent of pollution in the area and its role in the food web of an ecosystem. This study aims (1) to come up with a list of meiofaunal species present in the mangrove substratum, (2) to determine its density and abundance, and (3) to describe the meiofaunal environment in terms of temperature, salinity , pH, and oxygen content. The study was conducted in the mangrove habitat in Taklong Island Guimaras in February 1997. Thirty core samples were collected with a modified PVC core ( diameter=2.0 cm, length=15cm) from 3 areas: seaward, middle, and landward portions of the mangrove. There were eight broad groupings of meiofauna considered: nematodes, copepods, malacostracans, polychaetes, gastrotrichs, kinorhynchs, sipunculids, and others (including forams). The nematodes, of which there were 2 species observed, were the most abundant and comprised 42.14%. The copepods had 3 species observed and comprised 31.05%, 2 species of polychaetes comprised 5.04%,2species of gastrotrychs comprised 3.86% and malacostracans were 6.66%, kinorhynchs were 3.26%, and sipunculids were 0.89%. Unidentified organism which included foraminiferans, were 8.01 %. Range of meiofaunal density (number of individuals per cm'3 ) in three transects were 0.0042-0.1549 in the seaward area,0.0085-0.0785 in the middle area and 0.0021-0.0679 in the landward area. The nematodes had the highest density, and the sipunculids had the lowest density from the seaward to the landward area.Item Development of probiotics determination of LD50 of previously isolated indigenous vibriolytic bacteria, Pseudomonas aerugginosa JP4, to Penaeus monodon postlarvaeBillena, Ma. Thesa M. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2000-06)Previous studies showed that Pseudomonas aeruginosa JP4 is effective in eliminating pathogenic Vibrio spp. on shrimp. However, virulence studies on this strain are lacking. Hence, this study was conducted to test the pathogenicity of P. aeruginosa JP4, using different bacterial densities of 105, 106, 107, 108, 109 and 1010 CFU/ml. These were introduced to Penaeus monodon postlarvae 13 (PL13)and early juvenile (PL25) stages. After 3 days of monitoring, mortality rates and LD50 values were determined using Reed-Muench method. Results showed that shrimps can not tolerate higher bacterial densities with LD50 of 1.15 x 107 CFU/ml and 1.12 x 108 CFU/ml for PL13 and PL25 respectively. The relatively high LD50 values on shrimp stages PL13 and PL25 indicate a low virulence of the bacterial strain. Hence, P. aeruginosa JP4 maybe used as potential vibriolytic bacteria.Item Histomorphological study of the gonads of Pholas orientalisBeluso, Michelle O. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-04)A total of five "diwal", Pholas orientalis, two of which wore obtained from Hinigaran, Neg. Occ. on January 1995 and three from Lanas, Barotac Nuevo on February 1994, were examined for the histomorphological study of the gonads of the species. Among the five samples, two were males and three were females. No hermaphrodites were encountered. Macroscopical examination showed that the gonads were diffused in the visceral mass extending from the anterior to the posterior part of the animal. The gonads were arborescent in form and creamy in color. No external sexual differences were observed. Histological examination showed that male and female gonads were scattered in the visceral mass and concentrate most around the stomach. Male and female gonads consist of follicles which were lobular and embedded in the connective tissues. Three sexual maturity stages were observed among the five specimens, which are the late active, ripe, and partially spent stages. During the late active stages in both male arid female gonads, developing gametes (spermatocytes and young oocytes, respectively) are attached to the follicular wall with maturing gametes lying free in the follicular lumen. At the ripe stage, male gonads showed mature sperms free in the follicle lumen with sperm tails radiating into the center of the lumen. In females, ripe oocytes are free in the follicle lumen with some maturing oocytes still attached to the folli- cular wall by a slender stalk. Partially spent stage was observed only in females. Spent gonads showed spaces in ovarian follicles due to loss of ova through spawning (1938). Since there is a growing demand for "diwal", interest on this species had picked up lately. One of the earliest studies on P. orientalis was the study on the "diwal" fishery in Neg. Occ. conducted by Ablan (1938). The larval biology and mariculture of the angelwing clam, Cyrtopleura cos- tata, were studied by Gustafson, et al. (1991) and investigations into spawning and hatchery technique for P. orientalis are underway (Gustafson, et al., 1991). Studies on the biology of P. orientalis are few and in fact no literature regarding reproductive biology of the species was obtained. Thus, this study was carried out with the following objectives: (1) to determine the location of the gonads in the visceral mass of P. orientalis, (2) to describe the histomorphology of the gonads, and (3) to differentiate the gonadal conditions histologicallyItem Community structure of riverine mangrove stand in Brgy. Talokgangan, Municipality of Banate, Iloilo ProvinceBelaño, 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.Item A community study of mangroves in Brgy. Caliling, Cauayan, Negros OccidentalBarredo, Sherry Marie P. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2000-03)The species distribution of the mangrove community in Brgy. Caliling, Cauayanz Negros Occidental was studied using the transect line plot method with three plots for each of four stations established. Both stations 1 and 4 were located landward, while stations 2 and 3 were located seaward. Community structure Is described in terms of the following parameters; basal area, number of trees per hectare, importance value, relative density, relative frequency, frequency of species and relative dominance. Variations in these parameters are correlated with physico-chemical factors such as the air, water and soil temperature, water depth, salinity and pH. Ten true species were found In the mangals of the coastal environment of Brgy. Caliling, Cauayan, Negros Occidental. They were Avicennia aiba, Avicennia Janata, Avicennia manna, Campostemon phiiHpinensis, Excoecaria agallocha, Osbomia octodonta, Nipa fruticans, Brugeria cylindrica, Rhizophora apiculata and R. mucronata. Standard Basal Area was highest in Station 3 with 7.54 m/ha. In terms of zonation, the landward zone was found to have the highest Stand Basal Area with 11.15 m/ha. Station 2 had the highest density value of 33.92 %, whereas in terms of zonation, both the middle and seaward zone had the density value of 36.20 %. Avicennia marina was found to be the most dominant species and was observed to occupy sites with hypersaline conditions, in silty clay to muddy substratum, which may or may not be inundated by tidal flow most of the time.
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