Thesis (BS Biology) -- University of the Philippines Mindanao, 2009

This study was conducted to determine the food items present in the guts of Glossogobius sp. from Lake Mainit, Surigao del Norte, their percent composition by number, occurrence, mass of individual food item, and relative importance (RI) of each food item in the goby?s diet. A total of 64 guts were obtained, 56 of which came from adult samples and 8 from juvenile samples. Five food items were identified in the guts of glossogobius sp. and the RI index of these food items were determined. For the food items found in the guts of adult gobies, the RI values were the following: digested material (42.49), arachinids (28.49, fishes (26.75), crustaceans (1.78), and insects (0.49) from the guts of juveniles, the RI values were the following: digested material (42.75), fishes (27.5), tick (16.27), shrimps (9.58), and insects (3.91). for both age group, the digested matter, fishes, and ticks (arthopods) were the food items to have relatively high RI values. This is an expected outcome since fishes and small invertebrates are the usual components of goby?s general diet. Results of the t-test at p=0.05showed that there is no significant difference in both adult and juvenile Glossogobius sp. in their consumption of fishes and arthropods. This could mean that there is no shifting in goby diet from the juvenile to the adult stage