Role of fiddler crab from an intertidal flat of Setiu Wetland on the fate of sedimentary fatty acids

Abstract

Fatty acid compositions of fiddler crabs, Vea annulipes collected on a tropica intertidal flat at two sampling station in Setiu Wetland, Terengganu, were analysed as well as the surrounding surface sediments of their burrows, their food pellets and their feces. Vea annulipes tissue in Station A (Pengkalan Gelap) exhibited a higher concentration of fatty acids than Uca annulipes in Station B (Pengkalan Che Hamid). Food pellets revealed a higher contribution of saturated fatty acids and lower amount of polyunsaturated fatty acids and branched fatty acids than in the surface sediments samples. These differences of fatty acids compositions suggest an initial selection of food before the particles sorting in the buccal region. Vea annulipes feces also contains high amount of fatty acids, indicate that Vea annu/ipes play significant role in the fate of these lipids in intertidal flats. Comparative analysis of the fatty acids compositions of the different samples indicates that these fiddler crabs actively sorted bacteria in order to ingest them.