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Undergraduate Theses

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    The effect of different feeding schemes on mudcrab Scylla serrata larvae fed with Artemia salina
    Bachoco, Anabelle M. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1998-04)
    The study on the effect of different feeding schemes of mudcrab Scylla serrata fed with Artemia salina was conducted to identify the zoeal stage of S. serrata where an addition of Artemia to the diet results to higher survival, shorter intermoult duration, higher growth index, and shorter metamorphosis to the megalopa stage. All treatments were fed with Brachionus at a density of 20 ind./ml. Results showed that larvae fed with Artemia from day 0 had consistently high percent survival and this is significantly higher compared to other treatments. This was followed by larvae fed with Artemia at day 3 and at day 6. However, statistical analysis showed that there is no significant difference between the two treatments. Significantly low percent survival was obtained on larvae fed with Artemia at day 9. Results also showed that larvae fed with Artemia at day 0 metamorphosed to megalopa stage after 18 days and obtained the shortest average intermoult duration of 3.6 days and highest growth index of 5 6. This was followed by larvae fed with Artemia at day 3, day 6, and day 9. Artemia has high nutritive value which contributed to high survival, shorter intermoult period, high growth index and shorter metamorphosis period up to the megalopa stage.
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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.