The diet of telescopium telescopium and brotia binodasa in the mangrove area of setiu wetland as assessed by fatty acid biomarker

Abstract

Total lipid, lipid composition and fatty acid composition 1n the tissues, feces and sediment of Telescopium telescopium and Brotia binodasa collected from Setiu Wetland during dry season were used to investigated the food sources and diet of these gastropoda. In both months, the mangrove (detritus) in all samples was high as indicated by the mean percentage of PUFAs, 24.96% to 44.73% of total fatty acid. The high contribution of these markers in the gastropoda indicates that the present and important of photosynthesis based food supply mainly was mangrove (detritus). The occurrences of MUFAs with high percentage, which is 22.33% to 38.39% of total fatty acid content in the tissues, feces and sediment of the gastropoda was due o bacteria sources. This result indicates that gastropoda diet is also dependent on the attached bacteria on the partially decomposed leaf detritus suspended at the sediment. The mean percentage of dinoflagellate markers (Docosahexaenoic acids (22:6w3) together with 22:5w3, and I 8:4w3) in all samples gastropoda during both month ranged from 2.68% to 9.8%. This indicates that the gastropoda diet also dependent on dinoflagellate sources. The relatives contribution by diatom (20:5w3 and 16: I w7) markers, which was 0.93% to 4.92% respectively, suggesting considerable diatom sources in the diet of these gastropoda. Quantitative investigation of gut content analysis also indicates that these gastropoda used detritus as its main dietary component, supplemented by diatom and dinoflagellate. The mean percentage of gastropoda markers did not differ significantly between August and October. Its shows that gastropoda assimilate the same food sources through this two month for their diet.