UPV Theses and Dissertations
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Item Comparative development of larval performance of catfish hybrids (Clarias macrocephalus Gunther x Clarias gariepinus Burchell)Cabanos, Cerrone Salamat (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-03)Our native catfish, Clarias macrocephalus, is one of the most well-accepted fish in the country. With its soft and savory flesh, this species has high demand in local markets. However, due to its relatively slow growth and poor breeding activity, our native catfish has become rarely used nowadays in aquaculture. This led to the introduction of exotic and faster growing species like the African catfish, Clarias gariepinus, and Thai catfish, Clarias batrachus, which in turn, resulted to the near extinction of the native species. There is therefore a perceived need to undertake a breeding program involving this native catfish and other exotic species. One potential solution to increase our production rate of the native catfish is to hybridize it with the African catfish. Interspecific hybridization has been a popular breeding program utilized by researchers attempting to produce fish expressing hybrid vigor (positive heterosis) or for combining valuable traits from more than one species. This study is on the characterization of the early developmental stages of fertilized eggs and the comparison of larval performance (in terms of percent fertilization, hatching and larval survival) resulting from the artificial cross of Clarias macrocephalus (native catfish) and Clarias gariepinus (African catfish) and its parental species. In comparing the rates of egg development among crosses (all macrolecithal and discoidal cleavage), it was determined that fertilized eggs of the standard hybrid cross (C. gariepinus male x C. macrocephalus female) have a relatively faster rate of development than those from the reciprocal cross (C. macrocephalus male x C. gariepinus female). Results on determination of larval performance showed that there is no significant difference in percent fertilization and percent survival after 7 days between hybrid and parental crosses. However, in terms of percent hatching, the reciprocal hybrid cross (C macrocephalus male x C. gariepinus female), together with the C. gariepinus x C. gariepinus parental cross had a significantly higher percent hatching (P < 0.01) compared to the standard cross (C. gariepinus male x C. macrocephalus female).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 The effects of compost produced from rice Oryza sativa straw and sugarcane Saccharum officinarum trash on the growth of pechay Brassica rapaBrizuela, Karlyn G. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2014-03)This study was designed to determine the effects of the application of compost produced from rice Oryza saliva straw and sugarcane Saccharum officinarum trash on the growth of pechay Brassica rapa. Experiments were carried out in a residential lot in Brgy. Punta Taytay, Bacolod City, Negros Occidental. Four set-ups were made with three replicates each. Each set-up corresponded to one compost treatment: treatment (A) was the rice straw compost, treatment (B) was the sugarcane trash compost, treatment (C) was the combination of rice straw and sugarcane trash compost, and treatment (D) served as the control in which no compost was added. The results of the statistical tests showed that there was a significant increase in the growth of pechay plants treated with the three different types of composts as compared to the pechay plants treated with the control. Among all the treatments, pechay plants treated with the combination of rice straw and sugarcane trash compost showed the highest growth yield in terms of the mean plant height (19.61 cm), mean fresh weight (44.95 g), and mean number of leaves per plant (8.99) at the time of harvest. Results also that showed that there was no significant difference in the mean fresh weight and mean number of leaves per plant at the time of harvest in pechay plants treated with the rice straw compost and the sugarcane trash compost.Item Survival and growth of juvenile sea cucumber Holothuria scabra Jaeger (1833) in shrimp pond sedimentBriones, Jill D. (2012-03)Many high valued sea cucumbers e.g. Holothuria scabra are detritivores and thrive on organic matter and thus are potential bioremediating agents in eutrophic systems e.g. aquaculture ponds. Sea cucumbers cultured in shrimp ponds would act as natural bioremediators and lessen the organic matter content of the sediments hence make the pond environment more favorable for shrimp culture. This study looks at the feasibility of growing sea cucumbers in pond sediments for their bioremediating role and for their economic value. In this study, growth and survival of hatchery-produced H.scabra juveniles in Bare substrate (Treatment 1), Sand from natural habitat (Treatment 2) and Shrimp Pond sediment (Treatment 3) were compared after 5 weeks of culture. This study demonstrates that it is feasible to grow H. scabra juveniles in shrimp pond sediments without compromising their survival (p > 0.05). Results showed that those reared in Pond sediment grew best and significantly better compared to the other treatments (ANOVA, p<0.05). Juveniles grown in Pond sediment increased from mean weight of 3g to 14g while in the other treatments they just grew from mean of 2.7g to 8.7g. The consistently higher organic matter in Pond sediment could have contributed to better growth of sea cucumbers relative to other treatments. The bioremediating role of sea cucumbers was indicated by significant reduction in organic matter content in pond sediment by Week 5.Item Filtration rate of the marine clam, Kaltelysia sp. at different light intensities and fed with microalgae Isochrysis galbana and Chaetoceros calcitransBravo, Agnes Therese A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2005-04)Filtration rate of the marine clam, Katelysia with body lengths ranging from 5-6 cm and body weight from 45-65 g were determined by using the indirect method of suspension depletion and monitored by direct algal cell count. The effects of light intensity and algal species on the feeding behavior of the clam were determined. The first treatment involves total darkness where the basins containing the clams were covered with black plastic bag. In the second treatment, the basins with the clams were placed under ordinary light condition (12h light; 12h dark) and in the third treatment, the basins with the clams were positioned under a 20-watt bulb with continuous illumination (24h light). Results showed significant differences in the filtration rates of clams in different light intensities. It showed higher filtration rate in the total darkness treatment (F=0.132555907) followed by the 12h light: 12h dark treatment and lowest at the treatment provided with 24 h illumination. Apparently, illumination affected valve opening and siphon extension of the clam which also affected the filtration rate of Katelysia. Under total darkness treatment, the clams opened their valves and extended their siphons. Hence, there was highest ingestion of algae or filtration in total darkness which showed to be the optimum condition to stimulate or promote feeding. In the algal species preference experiment, the food used were either Isochrysis galbana, Chaetoceros calcitrans , or a mixture of both. Results showed that I. galbana had the highest number of cells ingested by the clams and removed from suspension. This is considered to be the preferred algal species (F=0.119713) followed by a mixture of both, and lowest on the treatment where C. calcitrans was used as food. The preference of the clam on Isochrysis galbana over Chaetoceros calcitrans could be its smaller size based on dry weight.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 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 A comparison of the gut contents of two Cardinal Fish, Fowleria vaiulae (Jordan & Seale 1906) and Fowleria variegata (Valenciennes 1832) in seagrass beds of Palompon, LeyteBiantan, Lindsay S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)Seagrass ecosystems support much of the Philippines’ coastal marine resources with the presence of a rich diversity of species, including the economically important ones. Understanding the diet composition of fishes through gut content analysis is essential for selecting species for aquaculture. Specimens of Fowleria vaiulae and Fowleria variegata were obtained through a trawl survey in the seagrass beds of Palompon, Leyte from November 2011 to February 2012. A total of 291 guts were analysed in this study. Results showed diet composition of both species is mostly made up of benthic invertebrates. A high percentage of chyme was observed in both species (46-65%), suggesting the consumption of easily digested materials. Also for both Fowleria species, it was observed that smaller size classes consume a higher number of small preys while larger size classes feed on larger preys. Small invertebrates such as tanaids and amphipods were more abundant in the guts of F. vaiulae and large preys of shrimps and crabs dominate the diet of F. variegata. This difference may be due to food partitioning in co-occurring species to avoid competition.Item Gonadal maturation Stages of Pinkfingered Vinegar Crab Episesarma chengtongense (Serene and Soh 1967) from Capiz, PhilippinesBarredo, Elilyn Farrah Belle B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)The pink-fingered vinegar crab Episesarma chengtongense is a growing fishery resource in the mangrove areas of the Philippines and may have potential for aquaculture and stock enhancement. To determine the gonadal maturation stages for both male and female for this species, a study was conducted from February to May 2015 of the pink-fingered crab from Capiz, Philippines. The determination of the gonadal maturation stages was based on the gross morphology and histological characteristics of the male and female gonads. In both sexes, gonad activity occurred throughout the study duration but for females, the peak egg bearing month was in May (87%). Body sizes of ovierous females were from 31.9 - 42.3 mm (CW). The greatest prevalence of ovigerous females was in the size range of 35-39 mm CW; the lowest percentage at 40-44 mm CW. Male crabs with mature testes were consistently high (70- 100%) in the four months duration of the study. The smallest female carrying eggs was 31.9 mm CW. Four stages of ovarian maturation were identified namely: developing (Stage II) with a yellow colored gonad, ripe (Stage III) with orange colored gonad, mature (Stage IV) with brown colored gonad and spent (Stage V) with light brown colored gonad. Two stages of male gondal maturation were identified namely immature (Stage I) with translucent to off white testes and mature.(Stage II) with creamy white testes.