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UPV Theses and Dissertations

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2016 - 20194

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Committee Member: search.filters.committeemember.Monteclaro, Harold M.

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    Catch composition, morphology, and some aspects of reproductive biology of Inimicus sinensis caught by baby otter trawl in Carles, Iloilo, Philippines
    Delloro, Emmanuel S. Jr. (University of the Philippines Visayas, 2019-06)
    ABSTRACT The catch composition of bottom otter trawl or “baby trawl” in Carles, Iloilo, Philippines was assessed from twenty (20) hauling operation from December 2017 to February 2018. A total of 97 fish species belonging to 15 orders and 53 families were identified. Considering shrimp as target catch, commercial and discarded bycatch were estimated to be greater than 95%. Fishermen are utilizing the bycatch species, however, discarding of fish occurs during operation and high grading of catches. Venomous fishes such as scorpaenid, tetrarogid, aploactinid, and synanceid fishes were commonly thrown back to the sea. The morphology of the synanceid fish, which comprises part of the discarded bycatch, was also described. Inimicus cuvieri (Gray, 1835) and Inimicus sinensis (Valenciennes, 1833) were morphologically alike. However, comparison between sexes of I. sinensis showed secondary sexual characteristics. Thirty-three morphological measurements, including standard length and fourteen meristic counts were made on 99 specimens (47 male and 52 female). Most morphometric characters differed significantly between sexes while no differences were found in meristic counts. Fish external features were longer in male specimens. The head and body region were bigger in female specimens. Factor analysis, Principal Component Analysis (PCA), extracted two principal components from the significantly different parameters that explained 62.29 % of the cumulative variances. Variables that caused the variation in two major components were head width, upper jaw, lower jaw, snout, pre anal fin, and anal fin base lengths in PC1 (45.65 %); and orbit diameter and anal fin base length in PC2 (16.64 %). These differences seem to be connected with their adaptation to environment, reproduction, and behavior. Additionally, a single pore at the anterolateral surface of the body and pores above the lateral line are also described here but association to other organs were not yet found. Finally, studies on some aspects of reproductive biology of I. sinensis, which dominates the fishing ground, were also conducted. Gonadosomatic index (GSI) and size of females at 50% maturation were determined by logistic method and by plotting the GSI with standard length. Fecundity was calculated from 49 mature individuals through subsampling at different gonad lobes. The size at 50% maturity was estimated to be 127.2 mm, using the logistic model, which was likely supported by the abrupt increase in GSI values above 125 mm SL. Fecundity was estimated at 47 187±25 009 oocytes for fish sized 115.33-194.57 mm. Both GSI and fecundity showed low correlation to fish length. Additionally, the histological analysis of the gonad showed that this fish is gonochoristic and multiple spawner.
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    Spatial distribution of eggs, larvae, and juveniles of Eyebrow goby (Oxyurichthys ophthalmonema) in Batan Bay Estuary, Aklan
    David, Alemar V. (University of the Philippines Visayas, 2019-06)
    ABSTRACT To understand better the biology of eyebrow goby Oxyurichthys ophthalmonema, the spatial distributions of its eggs, larvae and juveniles were investigated in Batan Bay Estuary, Aklan from October 2016 to September 2017 by employing a fisheries- independent methodology. Nesting grounds were located through burrow assessment followed by physico-chemical characterization of identified nesting grounds. Fifteen stations were established all over the study area. Results showed that O. ophthalmonema burrows were present in mudflats all over the study area. Of the 196 burrows assessed in detail, only 34 (17%) burrows had the presence of nesting adult O. ophthalmonema. For the spatial distribution of eggs, they were only found in Moto, Jalas and Kapispisan burrows. The highest observed density was obtained in Kapispisan at 5 eggs/burrow. For the spatial distribution of larvae, they were only found in 9 stations with the Jalas showing the highest density at 32 larvae per 100m3. For the spatial distribution of juveniles, they occurred in all stations but the density was higher in Kapispisan at 4 juveniles per 1000m2. The nesting grounds are located near the upper river tributaries with substantial mudflats and mangrove forest cover. The physico­-chemical characteristics of the nesting grounds were as follows: 24.50-26.67ppt for salinity, 29.75-31.25°C for water temperature, 3.26-3.55 for sediment pH (dry weight sediment, DW), 29.82-77.89μg/g for iron (DW sed), 2053-5378μg/g for Sulphur (DW sed), 1.50-8.24μg/g for phosphorus (DW sed), and 0.52-1.15% organic matter (DW sed). The physico-chemical characteristics of the water and sediments of Batan Bay Estuary is favorable to nesting of O. ophthalmonema. There is a need, therefore, to protect these habitats from threats that may negatively affect the nesting of O. ophthalmonema.
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    The response of Sandfish Holothuria scabra (Jaeger) juveniles to salinity and temperature changes
    Caber, Dieyna B. (University of the Philippines Visayas, 2016-02)
    ABSTRACT Sandfish Holothuria scabra is one of the most economically valuable species of sea cucumbers. Despite being the subject of many research projects and is currently cultured commercially, many of its basic physiological aspects are not yet known or established. This study was conducted to determine the effect of salinity and temperature on the oxygen consumption rate (OCR) of sandfish juveniles. Initially, acclimation to lower salinity was compared to direct transfer. ANOVA showed that the OCR of sandfish juveniles acclimated for 30 and 120 min to 30 and 25 ppt from ambient salinity (35 ppt) were not significantly different (P>0.05) to that of sandfish directly transferred. At 8 h, the OCR values at 30 min acclimation were 0.012 ± 0.002 mgO2/L/h/g at 35 ppt, 0.019 ± 0.004 mgO2/L/h/g at 30 ppt (direct transfer), 0.015 ± 0.001 mgO2/L/h/g at 30 ppt (acclimated), 0.019 ± 0.002 mgO2/L/h/g at 25 ppt (direct transfer) and 0.013 ± 0.002 mgO2/L/h/g at 25 ppt (acclimated). At 120 min acclimation, the OCR were 0.012 ± 0.002,0.019 ± 0.004, 0.015 ± 0.000,0.019 ± 0.002, and 0.013 ± 0.001 mgO2/L/h/g, respectively. In the second part of the study, when sandfish juveniles were exposed to salinities of 35 (ambient salinity) 30 and 25 ppt and temperatures of 34,29 (ambient temperature) and 24 °C over 8 h, their OCR values fluctuated at the highest temperature and even more so at the lowest temperature. Because the experiments at different temperatures were conducted separately, the results could not be compared statistically. However, due to the degree of OCR fluctuation it appears that the sandfish juveniles were stressed at 34 °C and more stressed at 24 °C. This is supported by stress indicators observed visually during the experiment. The absence of OCR fluctuation at ambient temperature (29 °C) indicates that this is the more appropriate temperature for sandfish culture. Based on the results of the study, salinity has no effect on sandfish OCR up to 10 ppt below ambient. These results may be useful for selecting optimal conditions for growth and survival, as well as selecting optimal locations for stock enhancement purposes.
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    Influence of cooling of crab (Scylla spp.) juveniles on the physiological changes and survival during storage
    Geromiano, Merlyn F. (University of the Philippines Visayas, 2017-06)
    ABSTRACT Considering that aquaculture of mud crabs is still dependent on wild seeds, mortalities associated with capture, handling and storage aggravates the problem of lack of seeds which is one of the major constraints affecting the development of the mud crab aquaculture industry. Having cold rooms for maintaining optimum environment for storage has been recommended, however these facilities are not available in all levels of the industry and can only be found in some of the major traders. To address this issue, this study tested a handling and storage scheme that can be used at various points along the harvest to market chain. In lieu of cooling crabs in a chamber, crabs were directly immersed in seawater of different temperatures (4°C, 7°C, 15°C and 29°C) and stored for 48h, 72h and 96h. Crabs that were cooled at 15°C for 3 min showed highest survival (88-90%) after 48h, 72h and 96h of storage. In addition, the least accumulation of glucose and lactic acid in the haemolymph was detected in crabs cooled at 15°C regardless of the storage period, which suggests that crabs were fess stressed when cooled at this temperature.