Undergraduate Special Problem
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/30
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Item Analysis of the gut contents of largehead hairtail, Trichiurus lepturus (Linnaeus, 1758) in Surigao Del SurBarros, Andrea Philine R. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)The traditional gut content analysis is one of the methods used which investigates feeding interactions, specifically those belonging to the aquatic food webs. The ribbonfish, Trichiurus lepturus is an economically important fish, and due to its high demand to other south-east Asian countries especially in the Philippines, there is a targeted fishery for this resource. However, the catch of this species in the country has declined recently. Since feeding habits are fundamental to understanding the ecology of a community, this study aimed to analyze the gut contents of Trichiurus lepturus. A total of 66 guts were examined in the study. The size ranged from 101-505 mm in total length. They fed mostly on fishes including Encrasicholina sp., and shrimps such as Acetes, Penaeus, and Lucifer. Moreover, there was an occurrence of cannibalism but only larger individuals. Microplastics were also evident in most of the size classes.Item Abundance, composition and distribution of phytoplankton in West Central Sulu SeaBria, Jed B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2008-11)A total of 28 stations were sampled for abundance, composition and distribution of phytoplankton in the West Central Sulu Sea. The samples were taken from 15-30 April 2007. Samples were collected by filtering 50L of surface water through a 20 pm mesh plankton net. A total of 96 phytoplankton genera were identified and were grouped into four major taxa. The overall mean density was 444.6 cells/L. Diatoms were the most abundant, with the mean density of 213.5 cells/L. The most abundant diatom genus was Chaetoceros. Blue-green algae showed the second-highest mean density of 127.6 cells/L. Trichodesmium was the most abundant genus among the two blue-green algae identified. Trichodesmium was also the most abundant genus, comprising 28.1% of all phytoplankton identified. Dinoflagellates and silicoflagellates were ranked third and fourth among the four major taxa with 77.5 cells/L and 28 cells/L, respectively. Protoperidinium was the most abundant dinoflagellate, while Amphorella was the most abundant silicoflagellate. They made up 6.2% and 1.2 % of all phytoplankton identified, respectively. The stations located along the coast of Palawan and near the Tubattaha Reef Marine National Park showed the highest phytoplankton concentrations.Item Influence of tidal levels on meiofaunal communities in a rocky shore area in Taklong Island National Marine Reserve, GuimarasBarbasa, Maria Carla A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)Rocky shores present an exuberant richness of life, which can be attributed to the hard substrate provided by rocks, necessary for the attachment of sessile organisms. There are many factors affecting community structure in rocky shores, including tidal levels. Tidal levels affect communities by periodically exposing them to air, causing drying up and dessication. Among those affected are meiofauna. Meiofauna in rocky shores are the least studied of all habitats, thus this study serves as baseline information regarding meiofauna in rocky shores, particularly in TINMAR, and how tidal levels affect them. Sorting and identification of meiofauna from 18 samples (5 TST, 5 TLT, 4 TMT, 4 THT) yielded 17 identified taxa, with Harpacticoids being numerically dominant followed by Tanaids (Copepods) and Polychaetes. Mean meiofaunal abundance was found to higher in lower tides (low and sub-tide), but differences were not statistically significant. A similar lack of significant differences between transects was shown for abundances of all and common taxa in edge or mid-section quadrats, although abundances appeared to be higher in low and sub-tidal transects. Cluster analyses based on similarities in abundance of taxa in the transect quadrats showed which asemblages are characteristic of mid- and high tide levels (Insect larvae and Sipunculids). Nematodes, which are typically dominant in soft-bottom substrates, were also most abundant in the upper intertidal in the present study. Other taxa like Tanaids, on the other hand, were more abundant in the low intertidal and subtidal transects. Harpacticoids were observed to be dominant in higher tides.
