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UPV Theses and Dissertations

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1986 - 198911990 - 20001

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Degree: search.filters.degree.Master of Science in Fisheries (Aquaculture)Keyword: search.filters.keyword.fingerlings

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    The effect of sex reversal treatment on the growth and survival of two strains of Nile tilapia (Oreochromis niloticus) and Mossambique tilapia (Oreochromis mossambicus) raised in brackishwater
    Badillo, Susan Delos Santos (University of the Philippines Visayas, 2000-08)
    A study to determine the effects of sex reversal (SRT) on the growth and survival of two strains of Nile tilapia (Oreochromis niloticus) and Mossambique tilapia (Oreochromis mossambicus) was conducted in four 2m x lm x 1.5m suspended hapa nets in UPV-IA Hatchery and Biology brackishwater fishpond for 75 days. The experimental treatments and codes used in this study were the following, Treatment GGn (GIFT/normal), Treatment GGsrt (GIFT/sex reversal), Treatment MMn (Moss/normal), Treatment MMsrt (Moss/sex reversal), Treatment GEn (GIFT-Egypt/normal) and Treatment GEsrt (GIFT-Egypt/sex reversal). Juvenile fry (average weight 0.0 1g) were subjected to sex reversal treatment by feeding fish diet with methyltestosterone at 60 mg per kg of feed for three weeks in freshwater. After SRT, the fingerlings were nursed in fine mesh net (0.5 mm mesh, 2m x 1m x 1m) for 30 days until the fish attained the weight from 3.0 g to 5.3 g. They were individually tagged by fin clipping method. They were acclimated from 0 ppt to 20 ppt prior to experimental proper. Juvenile fish of 3.40-5.44 g were communally stocked at 25 fish each treatment. Juvenile fish were fed with a commercial feed at 15% of their mean body weight per day from 1-30 days and 10% per day of their mean body weight from day 31-75 days culture period. Within the normal treatments, there was no significant (P>0.05) difference in mean body weights between Treatments GGn and GEn but both are significantly higher (P<0.01) than Treatment MMn. Within the sex reversed treatments, mean body weight in Treatment GGsrt was not significantly (P>0.05) different from Treatment GEsrt, but showed high significant (P<0.01) difference with Treatment MMsrt, similar to the normal treatments. The highest average final biomass of 808.88 g was obtained in Treatment GGsrt followed by Treatment GEsrt (795.58 g) and lowest in treatment MMn (367.63 g). The biomass gain of tilapia within the normal treatments ranged from 282.6 g to 672.95 g. Treatment GGn showed no significant (P>0.05) different from Treatment GEn, but both were significantly higher from Treatment MMn. The same trend was observed within sex reversal treatments. Treatment GGn obtained the highest (589.70%) percentage biomass gain and Treatment MMn (335.01%) was the lowest within the normal treatments. In sex reversal treatment, Treatment GGsrt has no significant difference with Treatment GEsrt, but both showed a high significant difference in Treatment MMsrt. Highest specific growth rate was observed in Treatment GGn (2.62 g day-1) and lowest in Treatment MMn (1.97 g day-1). Mean condition factor (MCF) of tilapia was highest in Treatment GGn (1.60), followed by Treatment GEn (1.56) and lowest in Treatment MMsrt (1.17). Within the normal treatments, Treatment GGn and GEn showed no significant difference (P>0.05), but both were significantly higher (P<0.01) than Treatment MMn. Within the SRT treatment, all treatments showed highly significant (P<0.01) difference from each other with highest at Treatment GGsrt and lowest at Treatment MMsrt. Mean survival ranged from 95% to 100%. Highest percent male population was obtained in hormone-treated fish (95-100%) compared to normal treatments (64-71%). Sex reversal treatment did not improve growth and survival of the two strains of Nile tilapia (O. niloticus), but improved the growth of Mossambique tilapia (O. mossambicus) significantly after 75 days under the conditions this experiment was conducted.
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    Effect of utilizing a combination of cow and chicken manures as organic fertilizer in fish pond
    Babalola, Julius (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 1986-03)
    An experiment was conducted utilizing twenty 40m2 ponds to investigate the effect of a combination of cow and chicken manures at the following ratios: 1000 kg/ha chicken manure: 3000 kg/ha cow manure; 1000 kg/ha chicken manure: 1000 kg/ha cow manure; 2000 kg/ha chicken manure only; 4000 kg/ha cow manure only; and no manure (control), on some selected physico-chemical properties of the pond, soil and water, primary productivity and production of red tilapia (0. mossambicus x 0. niloticus hybrid) fol­lowing an (RCBD) - randomized complete block design. Each pond was stocked with 40 fingerlings of red tila­pia and cultured for a 90-day period, at the Brackishwater Aquaculture Center of the University of the Philippines in the Visayas, College of Fisheries, Leganes, Iloilo, Philippines. Soil was analyzed for organic matter, phosphorus, nitrogen, pH, using Walkley and Black method, Olsen’s method, Kjehdahl method and pH meter respectively, following standard procedures described in method of soil analysis part II, (Black, 1965). Water oxygen was determined with YSI model 51-B, oxygen meter, salinity with Goldberg’s T/C refractometer pH with pH meter, phosphorus and NH3 - Nitrogen by methods described by Strickland and Parson, 1972. Reactive phosphorus of pond water improved due to the treatments, and supported fish food production leading to the high net fish yield obtained. Primary productivity, an index of living organisms in the pond, was high and suggests that the different treat­ments supported adequate fish food production. The highest net fish yield (651.03 kg/ha) was recorded in treatment IV (4 tons/ha cow manure only), while the lowest net yield (299.31 kg/ha) was recorded in treatment V (control). Treatments I (1 ton chicken manure and 3 tons cow manure/ ha) and II (1 ton chicken manure and 1 ton cow manure/ha) produced similar net fish yield, 431.97 kg/ha and 431.95 kg/ha, respectively. Treatment III, 2 tons/ha chicken manure only) gave a better net fish yield of 474.82 kg/ha, than treatments I and II. Cow manure can compare with chicken manure as organic fertilizer, in brackish water fish ponds for tilapia. A combination of 1 ton chicken manure and 1 ton cow manure per hectare could be as productive as 2 tons/ha chicken manure only, in tilapia production.