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Undergraduate Theses

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13

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Committee Member: search.filters.committeemember.Nievales, Marie FrancesHas files: Yes

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    The growth and yield performance of oyster mushroom (Pleurotus ostreatus Fries) using fish wastewater as fertilizer
    Arroyo, Karen T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2000-04)
    Oyster mushroom, Pleurotus ostreatus, is an edible wood-inhabiting fungi that continues to gain popularity in the Philippines, as well as in other tropical countries. With the use of modern technology, this mushroom can be grown in the Philippines, provided sufficient moisture is present. Its present cultivation is limited, perhaps due to insufficiency of planting materials and the limited knowledge about its culture. The main objective of the study was to establish the possibility of the replacement of urea, the commonly used fertilizer for mushroom cultivation by fish wastewater. The study also aimed to compare the effects of different concentrations of fish wastewater on the growth of mushrooms and determine which treatment produced the best results. A total of five groups were used: two control groups (positive and negative - using urea and water, respectively) and three experimental groups, the latter with different concentrations of fish wastewater serving as alternative fertilizer (A: 10%, B: 20%, C: 30%). Fruiting bags were inoculated with oyster mushroom spawn, and after a month of incubation, the growing mushrooms were assessed using the parameters of number, weight, length, and diameter. Results showed that the weight of oyster mushrooms was heaviest when the substrate was sprayed with plain water. However, the number of mushrooms harvested, their length, and the width of the pilei were not affected by spraying the substrate with urea or moistening these with up to 30% fish wastewater. The conclusions reached were: 1) when using sawdust as substrate for oyster mushroom cultivation, it is best to simply use water to maintain the moisture of the material; 2) sawdust used in combination with low concentration of fish wastewater (10%) can result in good production; 3) neither nitrogen nor urea may be a critical factor for the growth of oyster mushroom on sawdust; and 4) high amount of phosphorus and low potassium content of fish wastewater are favorable for oyster mushroom growth.
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    Effects of high and low protein diets on the gut evacuation rate of Tilapia nilotica
    Andrada, Bryan Andrew S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-03)
    Gut evacuation rate of young Nile tilapia, Tilapia nilotica fed commercial pelleted diets containing high or low protein diet were determined in the laboratory. The decline in gut fullness of the fish with time was examined at low and high protein diets. Two mathematical models were used to express the decline in gut fullness of the fish with time. Fish fed the low protein diet followed more closely the linear model while those fed the high protein diet followed the logarithmic model. The level of protein resulted in different gut evacuation rates (GER), expressed as coefficients b of the gut fullnesstime curve. GER values were higher in either linear or logarithmic models for fish fed low protein diet than for those fed high protein diet.
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    Diel feeding patterns of angelwing clam Pholas (Monothyra) orientales (Gmelin, 1970)
    Alojepan, Marbe Joy L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-04)
    Filtration rate of Pholas orientalis measured using the indirect suspension deletion method and monitored by direct algal cell counts. Phytoplankton Isochrysis galbana was used as food at an algal cell concentration of 2.5 x 103 cells ml ”'. Biological rhythms have been demonstrated in all animals and plants except bacteria. They control rhythmic patterns in behavior and physiology of a living organism. Biological rhythms, or oscillations, have a “period” that is measured from one arbitrary point or phase of the rhythm to the next occurrence of that phase. They are best demonstrated in a 24 h cycle or circadian cycle. There is a widely varying feeding activity in the 24h cycle of P. orientalis observed at a constant temperature of 27$C and hydrogen ion concentration of 35%o Like any other bivalves, P. orientalis has defined feeding periods equivalent to food uptake at 2400h-0300h. Such observation could be supported by a previous study by Corda stating that optimal feeding was obtained at total darkness. Periods of digestion occur shortly after the periods of feeding. P. orientalis when actively feeding were observed to have extended siphons, larger valve openings, and an inclination of 45. One primary external stimulus that affected filtration rate was the amount of light present. Biorhythms provide temporal information, such as the time of day or season of the year, which facilitates adaptation of the organism to internal or external environments.