UPV Theses and Dissertations
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Item Effect of salinity on the embryonic development of Portunus pelagicus and Charybdis feriatus eggsAlba, Kristine Margaret A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-03)The effect of salinity on the embryonic development of Portunus pelagicus and Charybdis feriatus was studied. The five different salinity levels used were 15 ppt, 25 ppt, 35 ppt, 45 ppt, and control (33-35 ppt) to compare their effect on the embryonic development of both species. One thousand newly spawned crab eggs were incubated in vitro in 4-L Nalgene fiberglass containers with 3-L of water at different salinity levels. Mild aeration that allows movement of eggs within the water column was provided. There were three replicates per treatment. Embryonic development of eggs (30 eggs were taken in every salinity level) was monitored daily up to hatching. The newly hatched larvae were then collected and counted. Results showed that during the incubation period, the most advanced stage of embryonic development for Portunus pelagicus was at 33-35 ppt and for Charybdis feriatus was at 35 ppt. There was normal embryonic development and hatching at 35 ppt, 45 ppt, and control (33-35 ppt) for Portunus pelagicus and at 15 ppt, 25 ppt, 35 ppt, 45 ppt, and control (33-35 ppt) for Charybdis feriatus. Eggs that were incubated at 15 ppt and 25 ppt for Portunus pelagicus died. There was normal embryonic development in both species when incubated at 45 ppt. Hatching rate for Portunus pelagicus at control (33-35 ppt) was 34.1 %, at 35 ppt was 16.1 %, and at 45 ppt was 5.8 %. Hatching rate for Charybdis feriatus at 35 ppt was 52.5 %, at control (33-35 ppt) was 21.2 %, at 45 ppt was 12.8 %, at 25 ppt was 6.7 %, and at 15 ppt was 0.3 %. To summarize, embryo of Charybdis feriatus eggs can withstand a wider range of salinity: from a low salinity of 15 ppt to a high salinity of 45 ppt, that makes them a euryhaline species. On the other hand, Portunus pelagicus cannot support embryonic development at lower salinities of 15 and 25 ppt that makes them a stenohaline species.Item Salinity tolerance of the angelwing clam, Pholas orientalis larvaeAguaras, Lovie Grace P. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2011-03)Pholas orientalis, locally known as “diwal” is one of the commercially important bivalves in the Philippines due to its delicate and sweet taste. An experiment was conducted to determine the salinity tolerance of the 24-hour-old larvae of this clam when reared in different salinity levels of 25, 30, 35, and 40 ppt. The experiment lasted for 15 days at a rearing temperature of 25° C - 27° C. Determination of survival rates and water change were done twice every week. The data gathered were then analyzed using one-way ANOVA. Results showed that survival rates were significantly high at salinities of 30-35 ppt and were significantly low at salinity levels of 25 and 40 ppt. It was also observed that there was an increasing trend of mortality with prolonged exposure to different salinity levels. This could be attributed to the limited osmoregulatory capabilities of the larvae. When reared at low salinity levels, larvae were faced with the danger of too much water entry which eventually led to death. Meanwhile, when reared at high salinity levels, the larvae died due to outward movement of water which resulted to dehydration. Information on the salinity levels that could be tolerated by diwal larvae will be an important factor in the development of larval rearing techniques for successful hatchery operations. The juveniles or seeds produced in the hatchery could be used to restock the depleted resources in the wild.Item Phytoplankton assemblages in contrasting seasons in the area of Banate Bay, Iloilo, PhilippinesAlvarez, Rose Ann T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)Banate Bay in Iloilo is one of the major food and occupation contributors in the Panay Island because of its rich biodiversity. This study investigated the phytoplankton assemblage and their diversity with respect to the contrasting seasons namely; December 2012 and June 2013 on the pre-selected nine (9) stations of the Coastal Ecosystem Conservation and Adaptive Management (CECAM) Project. Physicochemical parameters such as salinity, turbidity, DO, and pH did not display seasonality but total suspended solids (TSS) did, with increased values resulting from run-off from the surrounding watershed and rivers. Principal Component Analysis divided the stations during the two months into groups. Station B3 during June 2013 possessed low salinity level, low turbidity level, low pH level and a very high DO level. While the other stations during June 2013 and all the stations during December 2012 possessed higher salinity levels, higher turbidity levels, higher pH levels and lower DO levels. While the PC2 of PCA divided the stations according to the TSS levels and the temperature. All stations during December 2012 showed characteristics of higher TSS levels and lower temperatures while stations during June 2013 were observed to have low TSS levels and higher temperatures. A total of 86 genera falling under six families were identified from the samples, namely: bacillariophyceae (49 genera), dinophyceae (24 genera), cyanophyceae (6 genera), silicoflagellate (4 genera), chlorophyceae (1 genus), euglenophyceae (1 genus) and Miscellaneous (2 genera). In December 2012, a total of 84 genera were identified and 86 genera in June 2013. The top 10 genera with the highest mean densities were Bacteriastrum, Chaetoceros, Eutintinnus, Guinardia, Leptocylindricus, Lioloma, Protoperidinium, Thallasiothrix and Trichodesmium. Pearson’s correlation analysis revealed that water temperature and TSS were the most significant parameters influencing the distribution and seasonal shift in phytoplankton families and genera such as Bacillariophyceae, Others (composed of Euglenophyceae, Chlorophyceae, Myrionecta, and Globigerina), Protoperidinium, and Guinardia. pH and DO had minor influence on phytoplankton distribution. Shannon- Wiener diversity index as a pollution index suggested that the study area was incipiently polluted at stations Bl, B2, and B3 and marginally polluted at Stations B4, B5, GN1, GN2, GS1, and GS2. Despite potential effects of various human activities, the water quality and phytoplankton assemblage of this area has not reached an alarming situation. The current study provides valuable baseline data.Item Effect of salinity on survival and growth of Scylla olivacea crabletsAndres, Eileen Beth N. (Division of Biological Sciences, College of Arts ad Sciences, University of the Philippines Visayas, 2002-04)The effect of salinity on survival and growth of Scylla olivacea crablets was investigated. Salinities of 12, 16, 20, 24 and 32 ppt were used as treatments. Survival, molt interval and growth in terms of weight, carapace length and carapace width were measured for two molts. Growth was measured three days after every molt. There was no significant difference on survival of the crablets between salinities at molt 1. At molt 2, survival was significantly higher at 32 ppt compared to survival at 12 ppt but not significantly different from survival at 24, 20 and 16 ppt. Moreover, duration of survival was significantly higher at 32 ppt than at 16 and 12 ppt but not significantly different from durations of survival at 24 and 20 ppt. On the other hand, molt interval was not significantly different at salinities of 12, 16, 20, 24 and 32 ppt from C1 to C2 and from C2 to C3. Although the highest weight, carapace length and carapace width were observed at 20 ppt at molt 1, there was no significant difference in growth of the crablets at different salinities. At molt 2, the highest weight was at 32 ppt, the highest carapace length was at 24 ppt and the highest carapace width was at 16 ppt and 32 ppt. No significant difference was found in growth of the crablets between salinities at molt 2.Item Effects of pH and salinity on growth and survival of juvenile sea cucumber Holothuria scabra (Jaeger, 1833)Abagat, Christian M. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2012-03)Sea cucumber aquaculture could provide a solution to both enhance declining wild sea cucumber populations through restocking and provide sufficient beche-de-mer product to satisfy the increasing Asian market demand. The growth and survival of hatchery-reared Holothuria scabra juveniles at different pH-salinity levels were investigated. Juveniles were exposed for 14 days in six pH-salinity levels: Trt 1 (pH 6.5 — 6.7, 26-28 %o), Trt 2 (pH 6.5 - 6.7, normal salinity), Trt 3 (pH 7.0 - 7.2, 26-28 %o), Trt 4 (pH 7.0 — 7.2, normal salinity), Trt 5 (normal pH, 26-28 %o) and Trt 6 (normal pH, normal salinity) as the control. Multivariate analysis of variance (MANOVA) with repeated measurements revealed that pH and salinity had a significant effect on growth (length, width, and weight) and survival of H. scabra juveniles. Slight seawater desalination combined with high acidification (pH: 6.5-6.7) had lethal effects on H. scabra juveniles. While H. scabra juveniles could be reared in seawater with pH ≥ 7.0- 7.2 and salinity ≥ 26-28 %o, ambient seawater conditions remained the most suitable in rearing H. scabra juveniles for optimum growth and survival.Item Does a coral reef enhance the productivity of its surrounding waters?Peñafiel, Christen P. (University of the Philippines Visayas, 2019-06)ABSTRACT Coral reefs have long been assumed and continually claimed to be origins of very high productivity, but how they attract organisms from and export nutrients to their neighboring waters remains largely unknown. Specifically, this study aimed at determining the space-time dynamics of nutrients and biomass redistribution around Hibotkan Rock Sanctuary (HRS), Banate, Iloilo, a sanctuary reef established by Municipal Fisheries Ordinance No. 12 covering an area of 25 ha. Twelve (12) sampling stations were established for space-time nutrient profiling, phytoplankton count, and supplementary measurements of water parameters, and four (4) stations for fish (biomass) visual survey. Results were analyzed using spatio-temporal plots and the Pearson correlation matrix (5% significant level). Nitrite was observed to be limiting, while nitrate was the most abundant in the waters of HRS. The predominant temporal variations of nutrients followed the flood tide (FT) and ebb tide (ET) cycles. In general, the tidal current direction appeared to control the redistribution of the nutrients (NO3-, NO2-, PO43-, and SiO44-). This study further revealed that stations of high nutrient concentration usually coincided with low levels of dissolved oxygen (DO). Species of fish observed were all indigenous and well-known inhabitants of the coral reefs. Furthermore, no other families of fishes (such as those of commercial value) were caught on record. Overall, there was no clear indication of import or export of living biomass in the HRS area. It can be inferred from the results that the fabled high productivity of coral reefs has no clear scientific basis; consequently, the Marine Protected Areas (MPAs) concept also appears to have no solid foundation.Item The response of Sandfish Holothuria scabra (Jaeger) juveniles to salinity and temperature changesCaber, 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.Item The effects of different salinity and organic matter levels on the growth of blue-green algaeBantillo, Rosario R. (University of the Philippines Visayas, 1983-03)A one-month culture of lab-lab to determine the growth of blue-green algae in three levels of salinity ( 15 ppt = S1, 30 ppt = S2 and 45 ppt S3) and two levels of organic matter (3.4 to 4.4% = OM1 and 6.5 to 7.8% = OM2) was conducted using a twenty-two plastic containers (diameter = 43 cm; height = 49 cm) at the University of the Philippines in the Visayas Brackishwater Aquaculture Center, Leganes, Iloilo. The study utilized a 3 x 2 factorial experiment in completely randomized design with three replicates. Organic matter levels of the soil affected the chemical properties of soil and water (available phosphorus, reactive phosphorus, ammonia-nitrogen and pH). The higher the organic matter level, the higher the pH and the concentrations of ammonia and phosphorus. On the other hand, salinity did not apparently affect the fluctuations in ammonia, phosphorus and pH due to water replenishment to maintain treatment levels of salinity. Earlier rapid growth of blue-green algae commencing on the 3rd to the 15th day was observed at higher organic matter level. While at lower organic matter level, this occurred only on the 18th to the 28th day. Blue-green algae population (units/ml) was observed highest in treatment IV (S1 OM2; 1,262,113) followed by treatments III (S3OM1 761,338); II (S2OM1; 514,788); I (S1 OM1 494,375); V (S2OM2; 413,750); and, the lowest was obtained from treatment VI (S3OM2; 394,275). The relative percentage proportion of blue-green algae in the lab-lab complex showed that it composed 17.7% in treatment IV, 16.86 % in treatment III, 16.64% in treatment II, 15.82% in treatment I, 15.2% in treatment V and 14.9% in treatment VI. These, however, did not significantlyvary among treatments. A low correlation coefficient (r) between the population count and the selected parameters: reactive phosphorus, water pH, soil pH and available phosphorus was obtained while a negative correlation was obtained between the population and ammonia-nitrogen. Significantly higher biomass (ash-free dry weight) of lab-lab was obtained in higher organic matter (OM2) and at 45 ppt salinity (S3). The highest biomass (ash-free dry weight) was obtained in treatment VI (S3OM2; 0.160 g/cm2) while the lowest was obtained in treatment I (S1OM1 0.012 g/cm2). The algal count of lab-lab also showed a significant difference in the organic matter levels but no significant difference on the salinity levels. The highest algal count was obtained in treatment V (S2OM2; 6,773,542 units/ml) and the lowest count was obtained in treatment II (S2 OM1; 2,328,792 units/ml). However, the primary productivity based on O2 production showed a significantly higher production in the lower organic matter and at higher salinity level (30 ppt.). The highest O2 concentration was obtained in treatment III (S3OM1 5.759 ppm) and the lowest was obtained in treatment V (S2 OM2; 4.19 ppm).Item Effects of different levels of Pinus tebulaeformis pollen on growth and stress resistance of milkfish fry (Chanos chanos)Baldove, Analyn B. (University of the Philippines Visayas, 2010-06)The present study investigated the effects of different inclusion levels of pine pollen from Pinus tabulaeformis Carr. on the growth performance and stress resistance of milkfish fry (Chanos chanos). Milkfish fry with average body weight of 0.02 g were stocked in 15 tanks (40 fish per tank). A control diet (without pine pollen) and four experimental diets were prepared containing different levels of pine pollen at 0 g kg-1, 1.3 g kg-1, 2.6 g kg-1, 3.8 g kg-1, and 5.1 g kg-1 was fed to the experimental fish for 60 days. At the termination of the experiment, milkfish were subjected to acute ammonia and high salinity shock test. The result of feeding trial revealed that milkfish fed diets containing different levels of pine pollen stowed significantly higher growth (p < 0.05) in terms of weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio than the control diet. Survival of the milkfish during the trial were not significantly different among treatments (p > 0.05). Survival rates of milkfish groups exposed to high salinity stock test for 72 h were not significantly different from each other (p > 0.05). In contrast, results of the ammonia stress test revealed that the survival rates of milkfish fed with the diets containing (2.6 to 5.1 g kg-1) were significantly higher (p <0 .05) than those fed with diets containing 1.3 g kg-1 and the control diet Optimum dietary PP level was estimated using the quadratic model by using SGR and FCR values and found to be is 2.9 g kg-1 and 3.0 g kg-1, respectively. conclusion, pine pollen can be used as a supplement in milkfish diet to enhance growth and stress resistance against environmental stressors like ammonia.Item Influence of lunar cycle and tidal fluctuation of gonadal maturity of green mussel (Pema viridis) in Inner Malampaya Sound, Taytay, PalawanBaldevieso, A.A.G. (University of the Philippines Visayas, 2018-07)This study aims to identify the ideal period of harvesting cultured green mussel (Perna viridis) in order to attain larger flesh to shell ratio in inner Malampaya Sound, Taytay, Palawan by investigating the gonadal maturity in relationship to lunar cycle, tides, physicochemical and water productivity parameters. Twenty green mussel samples undergo histological analysis of gonad and 50 samples were measured for body indices weekly from October 2017 to March 2018. Results showed that the body and gonad indices have significant positive correlation with slight higher values during the first quarter weeks, and during a day before the low low tides. The peak of spawning was recorded during October. After which, partial spawning was observed and starts during the weeks of full moon until new moon with a duration of 1-3 week. Thus, the gonadal development/maturity of green mussel in the study is influenced by lunar cycle and tidal fluctuations. Among the water parameters monitored, salinity, pH, and temperature have a significant difference in the monthly, and lunar weeks levels. Furthermore, the drop in salinity might trigger the peak spawning. Diatoms (91%) dominate the plankton composition in the sampling area followed by small percentage of dinoflagellates (4%), zooplankton (2%), and cyanobacteria (2%) and ciliates (1%). The genus Coscinodiscus has the highest percentage (97.73%) among the diatom genera, this species could be one of the major algal diet of green mussels in the area. On the other hand, there was no significant correlation between the gonad index and body indices to the physicochemical parameters and water productivity parameters. Based on body indices and gonad index values, the ideal period to harvest green mussel is during the first quarter weeks. One out of 540 samples was found to be hermaphrodite.