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

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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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    Antimicrobial activity of macrofungal basidiomycetous mycelia against Vibrio spp.
    Bagacay, Jann Felnesh Exe V. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2023-06)
    Aquaculture is vital for global food security, producing 50% of the world’s fish. However, infectious diseases caused by fish pathogens like Vibrio species can lead to significant production losses. To address this issue, antimicrobial agents are commonly used. Macrofungal fruiting bodies and mycelia produce bioactive compounds with antimicrobial properties. This study aims to: (a) assess antimicrobial activity in isolated macrofungal samples against the fish bacterial pathogens Vibrio parahaemolyticus and Vibrio cholerae, (b) compare two methods (agar plug and crude extracts) for antimicrobial activity, (c) determine the minimum inhibitory concentration (MIC) using agar well diffusion and the agar plug methods, and (d) identify the macrofungal isolate with the highest antimicrobial activity. Ten morphospecies were collected from the University of the Philippines Visayas Miagao Campus. The samples were evaluated using the agar plug and agar well diffusion methods. The results showed antimicrobial activity against Vibrio cholerae and Vibrio parahaemolyticus. The activity index ranged from 0 to 0.83 and 0.22 to 0.78 for agar wells, and 0 to 1.00 and 0.70 to 1.30 for agar plugs, against V cholerae and V. parahaemolyticus, respectively. Termitomyces globulus and Trametes sp. 1 exhibited the highest activity indices using the agar plug and agar well diffusion methods, respectively. Statistical analysis confirmed significant differences in antimicrobial activity against both test organisms. These findings demonstrate the potential of macrofungi as a valuable source of antimicrobial compounds for controlling fish pathogens in aquaculture. Further research could lead to the identification and utilization of these compounds to minimize production losses and improve disease management in aquaculture.
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    Growth and nutritional content of red seaweed Gracilaria bailinae (Zhang et. al., 1995) grown under different fertilization scheme
    Almojuela, Kristine Marie T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2012-04)
    The accelerated development of fish aquaculture has caused many environmental problems. The most evident effects resulting from this activity is the increase in organic material, the reduction in dissolved oxygen and the excessive rise in inorganic nutrients such as nitrogen, phosphorous and carbon dioxide. The integration of seaweeds to fed cultured species has long been recognized as promising approach to reduce the excess nutrients released by aquaculture activity. The nitrogen and phosphate uptake kinetics, growth and nutritional content of the seaweed Gracilaria bailinae were studied in a series of outdoor tanks, fertilized with commercial fertilizer (NH4CI, NaNO3, and Na2HPO4) and shrimp culture waste water. The nutritional content of G. bailinae before and after fertilization was also determined through proximate analysis. Results showed a significant removal of dissolved nutrients by G. bailinae, although definite uptake rate could not be determined since the data were erratic and Michaelis-Menten model could not be applied. Seaweeds fertilized with shrimp waste water showed best specific growth rate (1.37±0.2 % d-1) over other fertilization scheme. This suggests that shrimp pond effluents could promote good growth on G. bailinae. Local G. bailinae had high protein content per se (14%) but became more enhanced when fertilized with commercial or shrimp waste water (23-32%). In contrast, its carbohydrate content dropped when heavily fertilized from 39% to 19%.