Undergraduate Theses
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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 Fisherfolk participation in (AMMMI) Barangay Palaca, Miag-ao, IloiloBianet, Hedda C. (Division of Social Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-03)People's organizations are formed by NGO's to help the fisherfolk uplift their economic well-being and to ensure their participation in charting their future. The Asosasyon Sang Magagmay Nga Mangingisda Sa Miag-ao, Iloilo (AMMMI), as a people's organization, has been existing for almost seven years. Its existence could be accounted for by the participation of the members in the organization. Thus, the study was made. The objectives of the study were met: 1. The members belong to a relatively homogeneous groups of low-income fisherfolk, households with common issues of economic survival and common aspiration to improve standard of living through their collective action. 2. The members have high level of participation in organizational, educational, and socio-economic activities of AMMMI.Item Gender analysis on the modes and extent of participation in Community-based Fishery Resource Management (CFRM) project in Malalison island, Culasi, AntiqueBenliro, Patriana Z P.; Eraste, Concepcion E. (Division of Social Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-03)A Gender Analysis on the Modes and Extent of Community Participation on CFRM in Malalison Island, Culasi, Antique was conducted in June 2002-Feruary 3003. The study aimed to determine the modes and extent of participation in Community- based Coastal Resource Management through the Community-based Fishery Resource Management (CFRM) Project using Program Monitoring with interview and focused group discussion. The difference on the modes and extent of participation of sex and membership in the association was also assessed. The study found out that male and female modes of participation in CFRM had no significant difference. The difference was in the extent of their participation, which was caused by the social roles they played. On the other hand membership in the organization was found to be a significant variable in analysing the modes and extent of participation.Item Cost and return analysis of milkfish operations in different farm sizes in Barotac Nuevo, IloiloBelgira, Gay Nanette (Division of Social Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1996-07)Milkfish (Chanos chanos) is the most important pond cultured fish specie in the Philippines. Barotac Nuevo, where the study was conducted, is among the most productive in the province of Iloilo in terms of milkfish culture. Cost and Return Analysis of Milkfish Production evaluates the economic performance of 30 milkfish farms in Barotac Nuevo, Iloilo. The economic performance of milkfish farms were assessed using profit, revenue, return on investment, rate of return on operating cost, and payback period. Investment and cost structure were also presented. Comparative analysis was done by farm size namely; small farms (less than 5ha), medium farms (5.01 to 20ha) and large farms (above 20ha). Farm investment increased as farm size increased. The highest yield per hectare per crop was obtained by medium farms (708.86kg) followed by large farms (566.76kg) and small farms (394.16kg). For all farms, economic profit decreased as fann size increased on a per farm basis. Small farms had an economic profit of P7,525.25. Medium farms had P55,157.66 while large farms had P131,575.59. Results showed that variable cost of medium farms(21,056.97) on a per hectare basis was higher than that of the large farms(20,298.67) while fixed cost of all farms on a per hectare basis decreased as farms size increased. Opportunity cost of farms on a per hectare basis decreased as farm size increased. Small farms had the lowest return on investment (14.30%) followed by medium farms (30.68%) and large farms (42.31%). Rate of return on operating cost for small farms was 56.03% while medium farms had 26.53% and large farms had 13.14%. Payback period of all farms decreased as farms size increased. Small farms had 6.99 years, medium farms had 3.29 years and large farms had 2.36 years. From all economic indicators presented, milkfish pond culture remains a profitable business venture in Barotac Nuevo, Iloilo. Small farms were found to be productive due to the close farm supervision devoted by owners themselves, but medium farms were found to be most profitable farm size to operate in milkfish pond culture in Barotac Nuevo, Iloilo. Large farms has lower yield because of the large area it occupies that an operator can hardly check all areas.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 histologically