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UPV Theses and Dissertations

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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.
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    Effects of tagging on Bohadschia marmorata marmorata in cages
    Alvañez, Arthur A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1989-10)
    A three month study was conducted on the sea cucumber Bohadschia marmorata marmorata confined in (1.33 m x 1.33 m x 0.33 m) cages modified after radian’s (1987, Unpubl.) experiment using (1 m x 1 m x 1 m) cages One hundred percent tag loss and 83.53% survival rate was observed on the tagged individuals. One hundred percent survival rate attained in the control cages showed that reduced density of one individual per 0.295m2 area of caged substratum is more favorable compared to Padlan's (1987, Unpubl.) one individual per 0.06 m2 area of caged substratum. This study was conducted at Sirban Iki point, Taklong Island, Guimaras, Sub-province of Iloilo from December 1988 to January 1989.