Undergraduate Special Problem
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Item Comparison of the length-weight relationship between starved and fed Scylla tranquebarica crabletsArroyo. 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.Item Fungal pathogen associated with Rhizophora stylosa: A comparative study between oiled and unoiled sites within Taklong Island National Marine Reserve (TINMAR), Nueva Valencia, GuimarasBalanga-an, Kristoffer (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2009-03)Mangroves, refer to an assemblage of trees and shrubs that inhabit the coastal intertidal zone in tropical and subtropical regions. They help in the soil formation, protection, and stabilization of our coastal environment as well as serve as shelter and breeding grounds for some of our marine organisms. A mangrove habitat represents the borderline between land and sea and is considered as one of the principal places where spilled oil and associated impacts converge. Oil spill threaten mangroves by predisposing the plants to fungal attacks thereby reducing their resistance to stress and diseases. Studies also show that certain fungi species are able to utilize oil in contaminated mangrove species. This study generally aims to compare the fungal population found on the diseased leaves of Rhizophora stylosa between oiled and unoiled sites in the Taklong Island National Marine Reserve (TINMAR). It also aims to isolate, characterize and identify fungi present in diseased leaves of Rhizophora stylosa using potato dextrose agar (PDA) culture media and determine their frequency of occurrence. Leaf samples were collected from two sites in TINMAR, one of which was contaminated by oil and the other one was not. Three trees were selected to represent each of the two sampling sites (oiled and unoiled), and to each of the selected trees, three diseased leaves were collected. The results of this study showed the dominance of some species of fungi namely, Aspergillus (40%), Penicillium (20%), Cladosporium (13.33%), Monilia (6.67%), Mycelia (6.67%), Humicola (6.67%), and Pestalotiopsis (6.67%). Five out of these seven genera were isolated from the unoiled site while six of these were isolated from the oiled site. Generally, the fungal population was observed to be greater in the oiled site than in the unoiled. This preliminary data indicate that R. stylosa might still be undergoing stress due to the remaining components of the spilled oil in the area. However, this can only be resolved by further monitoring.Item Fungal pathogens associated with Sonneratia alba: A comparative study between oiled and unoiled sites within Taklong Island National Marine Reserve (TINMAR), Nueva Valencia, GuimarasAlbacete, May Therese F. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2009-03)Majority of researches on impacts of oil spills on mangroves focused on the immediate post-spill acute effects. However, the persistence of oil in sediments at oil spill sites has been reported in a number of published works. As such, this remaining oil could serve as source of stress to mangroves resulting into the expression of sub-lethal effects such as changes in foliage and canopy, abnormalities in reproductive structures among others. Furthermore, oil in mangroves also has the potential of increasing fungal attacks due to their impairment of natural defense mechanisms such as salt removal from leaves and trunks. Thus, this study was conducted to determine if there was a difference in fungal species composition and frequency of occurrence of fungal population of mangrove leaves collected in oiled and unoiled areas within Taklong Island National Marine Reserve, Nueva Valencia, Guimaras following the spill that occurred in August I1,2006. Fungi from diseased leaves of Sonneratia alba were isolated and characterized using Acidified Potato Dextrose Agar (APDA) for samples collected in January 2009 only. A total of 7 and 6 species were identified from among the isolates in oiled and unoiled sites. Although there is a little difference in species composition, almost all the isolated species was frequently occurring in both oiled and uncoiled sites. Gliomastix morurom (5.8%) in the unoiled site was only frequently occurring. The results may imply that difference in frequency of occurrence of certain species might be an indicator for sub-lethal effects of oil but needs further investigations to consider environmental factors among other factors.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 Relation of size and sex to the natural diet of the red crab Charybdis feriatus Linnaeus (Brachyura: Portunidae) from Pilar-Capiz Bays, Northern PanayAlabia, 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.Item Comparison of the growth of green algae, Nephroselmis sp. at different mediaAgana, 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.Item Histopathology of the gill, abdomen, and lymphoid organ of giant black tiger shrimp (Penaeus monodon) infected with white spot syndrome virus (WSSV)Apines, John S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2004-03)Histological changes in giant black tiger shrimp, Penaeus monodon, were investigated at various time intervals after injection with white spot syndrome virus (WSSV). After infection with the virus, mortalities were observed. Gills, abdomen, and lymphoid organ (LO) were then dissected and subjected to histological examination. The study revealed that the lymphoid organ was the most severely damaged compared to the gills and abdomen. The abdomen, although low in prevalence, was one of the target organs of the virus. Light microscopy showed the aggregation of hemocytes in the abdominal muscles of the shrimp. The infected shrimp were found to have a high prevalence of apoptotic cells. The results of this study supported the earlier findings that cell death in viral infection may have resulted mainly from apoptosis and that increasing numbers of apoptotic cells probably caused the death in WSSV-infected shrimp. Moribund shrimp had extensive deterioration of vital tissues such as the gills and lymphoid organs, thus affecting vital processes in the shrimp body. Gross signs of lethargy and weakness were observed in the moribund shrimps. Hemocyte aggregation, as well as formation of spheroids, were observed in the hemal sinuses of the LO, the abdominal region and the gills. The results are discussed in relation to the hypotheses of acquired tolerance and quasi-immune response in shrimp.Item Species composition and distribution of fish larvae in Lianga Bay, Surigao del SurAcabado, Cristy S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2007-03)The species composition and distribution of ichthyoplankton in Lianga Bay, Surigao del Sur was investigated in June 2004. A total of 37 families were recorded from horizontal tows collected in 32 sampling stations. The most dominant larvae were Gobiidae and Pomacentridae, which comprised 20.4% and 16.0% of all larvae sampled, respectively. Overall larval density was 4.2 ind. 100 m-3 (n=32; sd=5.0), with highest concentrations in the inner portion of the bay particularly in the west and southwest portions. On the other hand, egg density (mean=0.9 eggs m-3; n=32; sd=0.9) showed highest concentration near the coastline but further from the central basal portion of the bay. Patches of high egg concentrations suggest that Lianga Bay may serve as spawning ground for some species.Item 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.Item Physiochemical factors affecting mangrove distribution and occurrence in selected sites in the Province of AntiqueAgapin, Antonio, Jr. D. (Division of Biological Sciences, Bachelor of Science in Biology, University of the Philippines Visayas, 2009-03)Mangrove forests are unique inter-tidal ecosystems comprised of taxonomically diverse, salt-tolerant tree and other plant species that are primarily found o.i relatively sheltered coastlines, deltas, estuaries, and lagoons in tropical and subtropical regions of the world. The objective of this study is to generally determine the physicochemical factors influencing the distribution and occurrence of mangroves in selected sites in the Province of Antique and to specifically measure selected physicochemical factors influencing the distribution and occurrence per species per municipality and correlate selected physicochemical factors like soil and water salinity, soil and water pH, and soil and water temperature influencing the distribution and occurrence per species per municipality using Pearson Correlation Coefficient. There were 224 plots established in 11 municipalities in the province of Antique. Twenty-five plots were established in Anini-y, 44 in Hamtic, 11 in San Jose, 5 in Belison, 18 in Patnongon, 23 in Bugasong, 11 in Barbaza, 9 in Tibiao, 26 in Culasi, 23 in Pandan, and 29 in Semirara. A total of 27 true mangrove species belonging to 12 families were found in the 11 municipalities of Antique. The 12 families are Family Avicenniaceae represented by Avicennia alba , Avicennia marina, Avicennia officinales, and Avicennia rumphiana', Family Combretaceae represented by Lumnitzera racemosa and Lumnitzera littorea; Family Euphorbiaceae represented by Excoecaria agallocha; Family Lythraceae represented by Pemphis acidula; Family Meliaceae represented by Xylocarpus granatum and Xylocarpus moluccensis; Family Myrsinaceae represented by Aegiceras coniculatum and Aegiceras floridum; Family Myrtaceae represented by Osbornia octodonta; Family Arecaeae (Palmae) represented by Nypa fruticans; Family Rhizophoraceae represented by Bruguiera cylindrica, Bruguiera gymnorrhiza, Bruguiera sexangula, Ceriops decandra, Ceriops tagal, Rhizophora apiculata, Rhizophora mucronata, and Rhizophora stylosa; Family Rubiaceae represented by Scyphiphora hydrophyllacea; Family Sonneratiaceae presented by Sonneratia alba, Sonneratia caseolaris, Sonneratia ovata; and Family Sterculiaceae represented by Heritiera littoralis. For Soil pH, the highest value of 8.87 was observed in the municipality of Hamtic and the lowest at 6.32 in the municipality of Semirara. Overall mean soil pH was 7.31. For Water pH, the highest value of 8.96 was observed in the municipality of San Jose, and the lowest value of 6.29 in the municipality of Tibiao. Overall mean water pH was 7.23. For salinity, it ranged from 3.1 ppt (Tibiao) to 27.47 (Semirara) and the overall mean was 13.37 ppt For Water Temperature, the highest value of 29.48 °C was observed in Anini-y & the lowest value of 24.74 °C in the municipality of Semirara with an overall mean of 27.40 °C. For Soil Temperature, the highest value of 30.2 °C was observed in the municipality of Belison & the lowest value of 24.97 °C in the municipality of Semirara with an overall mean of 27.50 °C. Among the species present, Aegiceras floridum showed significant correlation with Soil pH (favor low soil pH), water pH ( favor low water pH), salinity ( favor high salinity), soil temperature (favor high soil temperature) and water temperature (low water temperature), A. rumphiana showed significant correlation with water pH (favor low water pH) and soil temperature ( favor low soil temperature), B. cylindrica showed significant correlation with soil pH ( favor high soil pH), C. decandra showed significant correlation with water pH (favor low water pH) and salinity (favor high salinity), L. littorea showed significant correlation with soil pH (favor high soil pH), water pH (favor high water pH), salinity (favor high salinity), soil temperature (favor high soil temperature) and water temperature (favor high water temperature), O. octodonta showed significant correlation with soil pH (favor high soil pH), water pH (favor low water pH), salinity ( favor low salinity), soil temperature (favor high soil temperature) and water temperature (favor low water temperature), S. caseolaris showed significant correlation with water pH (favor low water pH), salinity (favor low salinity), soil temperature (favor low soil temperature) and water temperature (favor low water temperature) and S. ovata showed significant correlation with soil pH ( low soil pH), salinity (favor low salinity) and water temperature (favor low water temperature). Species like A. corniculatum, A. alba, A. marina, B. sexxangula, E agallocha, H. littoralis, L racemosa, N. fruticans, R apiculata, R mucronata, R stylosa, S. alba, X. granatum and X. moluccencis showed wide tolerance (no correlation) in all physicochemical factors (Soil Salinity, Water pH, Soil pH, Soil Temperature and Water Temperature).