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UPV Theses and Dissertations

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Degree: search.filters.degree.Bachelor of Science in Fisheries

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    Analysis of the lipid content of micro algae species used in Philippine aquaculture for their potential in biodiesel production
    Ferriols, Victor Marco Emmanuel N. (Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2008-03)
    This study looked into the proximate lipid content of four micro algal species (Chaetoceros calcitrans, Tetraselmis tetrahele, Nannochloropsis sp., and Chlorella sp) and one macrophyte (Chaetomorpha sp.) commonly used in Philippine aquaculture. Prior to the proximate analysis using the method described by Bligh and Dyer (1959), the four micro algal species were cultured for five days in 1 L vessels fertilized with TMRL enrichment media. Proximate gravimetric analysis showed that the average lipid content of Tetraselmis tetrahele at 24.11% was significantly higher (p < 0.01) when compared to all the algal species tested. Comparing the mean lipid content of all micro algal species against that of the macrophyte also revealed a significantly higher (p < 0.01) lipid content at 17.40%. Growth rates for all the micro algal species over the culture period was also measured, with the highest growth rate exhibited by T. tetrahele at 1.15 divisions per day. Projected estimates for micro algal production yields of oil from a 1-hectare pond at 0.5 m depth were also calculated from the lipid analysis data, a showing that the highest yield of oil (7.29 tons) can be attained by culturing T. tetrahele. This number was higher than estimated reports for oil production from an area of 1 hectare dedicated to either jatropha (1.7 tons) or coconuts (5.0 tons). This makes the culture of micro algal species a potential option for producing feedstock for biodiesel production.
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    Growth performance, feed utilization and survival against stress test of juvenile Nile tilapia Oreochromis niloticus fed with lactic acid bacteria (lab) Pediococcus acidilactici
    SO, April Dawn P. (University of the Philippines Visayas, 2016-06)
    ABSTRACT The present study evaluated the growth performance, feed utilization and survival against stress test of Nile tilapia, Oreochromis niloticus fingerlings (mean initial average body weight 0.39g ± 0.01) fed with commercial probiotics. The experimental design was randomized, with four treatments and four replicates: Treatment 1 (control) with 0g kg-1 probiotics inclusion, Treatment 2 with lg kg1 probiotics inclusion, Treatment 3 with 2g kg'1 probiotics inclusion and Treatment 4 with 4g kg'1 probiotics inclusion. Three hundred and twenty fingerlings were distributed in 16 50L containers and fed for 40 days. Differences in the mean values of total weight were found at the end of the experiment. After 40 days of feeding trial, percent weight gain (%WG), specific growth rate (SGR) and and feed conversion ratio (FCR) was significantly high (P < 0.05) in treatments with probiotics compared to probiotic-free treatments; no differences on survival rate (SR) was observed among dietary treatments. The best growth performance and feed conversion was observed in fishes fed with 4g kg'1 probiotics inclusion. Challenge was done immediately after the period of application. The stress challenge test was done to the experimental animals by exposure to oxygen deficient water or asphyxia. No significant difference (P < 0.05) on SR was observed after 3 hours exposure to asphyxia. It could be concluded that probiotics can improve growth performance and feed utilization. However, further studies are recommended to assess the effects of probiotics to fish when exposed to asphyxia.
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    Assessment of induced stress as schemes for selectively removing fish with opercular deformities in hatchery produced milkfish (Chanos chanos) seeds
    Cordero, Christian P. (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2015-06)
    The effects of different types of induced stress were tested as schemes for the elimination of fish with opercular deformities in hatchery produced milkfish seeds. Salinity and pH were used as the main stressors for milkfish larvae of different ages. Induced salinity stress was initially tested on larvae at 15 days post-hatch (dph) by directly transferring the larvae from its rearing water salinity of 32 ppt to salinities of 10 ppt, 25 ppt, 35 ppt and 45 ppt. Almost all of the larvae subjected to salinity stress dies, hence, it was deemed necessary to examine the influence of handling stress and to determine the age of larvae that could tolerate handling. Larvae of different ages (from 10 dph to 22 dph) were thus subjected to handling stress by collecting them from the mass rearing tank and transferring them to 1000 ml beakers where survival was monitored. Results showed that milkfish larvae were able to withstand handling stress beginning 21 dph. Considering that milkfish fry (21 dph) are already known to tolerate direct transfers to various salinities, the next experiments were focused on pH stress. The suitability reduced or increased pH as stressors were initially tested by directly transferring larvae from normal seawater (pH 7.50) to acidic water (pH 6.5-7.0) and basic seawater (pH 8.0-8.5). Results revealed several advantages of reducing pH levels over increasing pH levels, which included the comparably higher larval survival, the lesser amount of chemicals required to change pH levels and the corresponding cost of these chemicals. A range finding test was then conducted to determine the optimum pH that could selectively remove fry with opercular deformities by directly transferring fry reared in normal seawater (pH 7.50) to seawater with reduced pH: Trt 1-pH 6.5; Trt 2-pH 6.6; Trt 3-pH 6.7; and Trt 4-6.8. Larval mortalities were recorded after 1 h, then 25% water change was done for all treatments which were monitored further for mortalities after 2h, 3h, 5h, and 24h. The surviving larvae from all the treatments were reared further for 18 days (until 40 dph) in order to monitor opercular deformities which can observed only when the larvae have metamorphosed into juveniles. Results showed that a sudden drop in pH of normal seawater to pH 6.5-6.7 selectively removed all the fish with opercular deformities in hatchery produced milkfish seeds; at such pH range, more than 90% survival of milkfish fry was obtained with this batch of larvae and all the surviving fish had no opercular deformities.