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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/30

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Committee Chair: search.filters.chair.Tayo, Gilma T.SDG: search.filters.sdg.SDG 14 - Life below water

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    Gonadal maturation Stages of Pinkfingered Vinegar Crab Episesarma chengtongense (Serene and Soh 1967) from Capiz, Philippines
    Barredo, Elilyn Farrah Belle B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)
    The pink-fingered vinegar crab Episesarma chengtongense is a growing fishery resource in the mangrove areas of the Philippines and may have potential for aquaculture and stock enhancement. To determine the gonadal maturation stages for both male and female for this species, a study was conducted from February to May 2015 of the pink-fingered crab from Capiz, Philippines. The determination of the gonadal maturation stages was based on the gross morphology and histological characteristics of the male and female gonads. In both sexes, gonad activity occurred throughout the study duration but for females, the peak egg bearing month was in May (87%). Body sizes of ovierous females were from 31.9 - 42.3 mm (CW). The greatest prevalence of ovigerous females was in the size range of 35-39 mm CW; the lowest percentage at 40-44 mm CW. Male crabs with mature testes were consistently high (70- 100%) in the four months duration of the study. The smallest female carrying eggs was 31.9 mm CW. Four stages of ovarian maturation were identified namely: developing (Stage II) with a yellow colored gonad, ripe (Stage III) with orange colored gonad, mature (Stage IV) with brown colored gonad and spent (Stage V) with light brown colored gonad. Two stages of male gondal maturation were identified namely immature (Stage I) with translucent to off white testes and mature.(Stage II) with creamy white testes.
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    Molluscicidal activity of tabaco dust against the brackishwater pond snail Telescopium telescopium (Gastropoda: Potamididae)
    Azucena, Paulene C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    Telescopium telescopium, a molluscan potamidid snail thrives in the muddy substrates of brackishwater ponds in the Philippines. It occurs in considerable numbers but uncontrollable increases in its population poses serious threats to pond production. Tobacco dust is considered as a potential biomolluscicide that is able to control pond snail infestation. A short-term bioassay was conducted to know the effectiveness of tobacco dust as a molluscicide against T. telescopium by determining its median lethal concentration (LC50) after a period of 96 hours. Twenty-five telescope snails were subjected to varying concentrations of tobacco dust, from 0 to 1.0 kg/L at 0.2-kg increments. Three replicates were done for every treatment. Counting of dead snails was done after 48 and 96 hours of exposure. Snails exposed to varying concentrations of tobacco dust exhibited several defense mechanisms such as avoiding the toxic solution by crawling out of the area, closing their operculum and retracting their bodies toward their shell. Highest snail mortality was observed at the 1.0-kg/L treatment. After the 96-hr. exposure time, the concentration of tobacco dust that proves to be lethal to 50% of the snails was computed to be 0.5849 kg/L. Indeed, tobacco dust is an effective molluscicide against brackishwater pond snails, particularly T. telescopium.
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    Comparison of the length-weight relationship between starved and fed Scylla tranquebarica crablets
    Arroyo. Ritchel B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    This study aimed to determine the length-weight as well as the width-weight relationships of the Scylla tranquebarica crablets when starved and fed during the intermolt and premolt stages. Molt stages were identified and then the crablets were subjected to feeding or starvation for 36 days. Regression analysis showed the length-weight relationship of the Scylla tranquebarica crablets, including carapace length, carapace width, and body weight when fed and starved. Regression lines for each category differed from one another. Results showed that the fed crablets in intermolt and premolt stages showed greater body weight gain per unit carapace length and carapace width. The intermolt fed gave the highest weight gain per unit length and unit width among the treatments. Equations for interconversions of length and weight and for length and width are reported for the premolt and intermolt stages when fed and starved.
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    Echinoid and Ophiuroid species in Taklong Island National Marine Reserve (TINMR), Guimaras
    Almira, Eugenie Marie A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)
    Taklong Island National Marine Reserve (TINMR) in Guimaras is one of the Philippines’ marine protected sites established to ensure continuity and productivity of marine organisms such as echinoderms. The study aims to determine the community structure of echinoid and ophiuroid species in selected shallow coastal sites around Taklong Island within TINMR. Sampling was done twice (June 2014 and Jan 2015) using belt transect method for echinoid species in three selected sites and random quadrat method for ophiuroid species in two sites. A total of twelve (12) echinoid and six (6) ophiuroid species were recorded. The most numerous echinoid and ophiuroid were Echinotrix calamaris and Ophiocoma erinaceus, respectively. The diversity of echinoids (H’= 0.37-0.95) and ophiuroids (H’= 0.53-1.40) in Taklong Island was relatively low. Presence and abundances of many echinoids and ophiuroids in a site varied with sampling time. Variation may be due to differences in substrate characteristics such as sea grass cover and coral cover as well as environmental factors.
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    Relation of size and sex to the natural diet of the red crab Charybdis feriatus Linnaeus (Brachyura: Portunidae) from Pilar-Capiz Bays, Northern Panay
    Alabia, Irene Dolorfino (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-03)
    A total of 395 (males= 282; females=113) specimens of the red crab Charybdis feriatus were collected from Pilar-Capiz Bays from January-December 2002 and were used for the present study. Relative fullness index were computed for both sexes of different size classes. Results showed that stomachs of females were slightly fuller than that of males. Similar observation was made between juvenile and adult specimens. A total of 75 (males= 57; females= 18) gut contents were analyzed in detail. Major food items in the diet of the crabs include unidentified matter, unidentified eggs, fish, crab, and shrimp remains. Frequency of occurrence and combined visual estimation of unidentified organic matter were used for the examination. No dietary differences due to ontogenetic change were observed in the species while diet of male crabs were found to be more varied than those of females. However, frequency of occurrence of major food items in the stomachs of both sexes was comparable.
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    Comparison of the growth of green algae, Nephroselmis sp. at different media
    Agana, Julie Ann E. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2004-03)
    Green algae play a significant role in the maintenance of the hatchery of economically important crustaceans, where a continuous supply of algae is needed to feed the larvae. Moreover, microalgae have the potential to be used to produce chemically complex molecules, which are difficult to synthesize. Thus, the present study was conducted to compare the growth of the green algae, Nephroselmis sp., using three different media. Specifically, the study aims (1) to compare the effect of different media on the growth of Nephroselmis sp. and (2) to determine which medium is the most suitable for growth of Nephroselmis sp. The result of the study showed that there was no significant difference in the growth of the green algae Nephroselmis sp. at three different media. The results showed that quantities of chemical composition of the different media are already sufficient for the growth of Nephroselmis sp.
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    Comparative growth rates and gross morphology of hybrid catfish Clarias gariepinus (female) x Clarias macrocephalus (male)
    Agase, Mark Christian A. (Division of Biological Sciences, Bachelor of Science in Biology, University of the Philippines Visayas, 2004-03)
    Catfishes are among the groups that has been considered economically important fishes in the Philippines and in other countries. The freshwater catfish Clarias macrocephalus is native to the Philippines but it is becoming scarce in many natural habitats. It is a favorite food dish due to its tender and delicious meet. Aquaculturists these days focus more their attention to the culture of exotic species like Clarias gariepinus and Clarias batrachus that in turn resulted to the near extinction of the native species. There is therefore a need to undertake a breeding program involving this native catfish and other exotic species.A 12-week study was conducted to compare the growth rates of the hybrid catfish C. macrocephalus (♂) X C. gariepinus (♀) in natural ponds and laboratory rearing conditions. In addition, the length-weight relationship was also determined. Gross morphology was also noted in the experiment.Results showed that the trend for SGR of the hybrid in natural pond and laboratory rearing conditions from weeks 2 to 12 is decreasing. Continued feeding of the hybrids on artificial diets results in poor fish growth. T-test revealed that there is a significant difference on the SGR for both the length and weight with hybrids in natural pond rearing conditions being consistently higher than the laboratory set-up.From the linear regression equation, there was no homogeneity of regression, coefficients, or slopes in the mean body lengths (MBL) and mean body weights (MBW) of me hybrids in the natural pond and laboratory rearing condition. It simply means that there is a significant difference on the growth rates of the hybrid as to the type of environment they are reared. The product-moment correlation showed that there is a linear relationship between the length and the weight of the hybrid fish, 7.9305378 X 104 being the constant. Gross morphology of the hybrids includes the appearance of a trident-shaped occipital process, which was not pointed and narrow as in the case of the parent C. gariepinus. A turtle shell-like design arranged bilaterally characterizes the dorsal side of the head. A modification of the dorsal fin was also noted as to the presence of the adipose fin at the posterior end of the dorsal fin, which was about 3-5 mm in length.