Food sorce of cockle, Anadara ovalis, mud clam, Polymesoda expansa and oyster, Isognomom sp. as indicate by fatty acid markers, in the Setiu Wetland, Terengganu

Abstract

The study of fatty acids as the markers aims to investigate the food sources and determine the composition of fatty acids of Anadara ova/is, Polymesoda expansa and /sognomom sp. and in the Setiu Wetland. The sampling was done at the beginning of monsoon season. Isognomom sp. has the highest concentration of total lipid with the mean concentration is 0.2221 g g1

dry

wt and fatty acid with mean concentration 10.37 µg g- 1 compare to other species. There are no significant difference in the total lipid concentration between A. ova/is and P. expansa (P> 0.05) with mean concentration 0.089 1 g g- and 0.097 g g- 1 • There are five classes of fatty acids found in the tissues of bivalves as saturated fatty acids (SAF As), mono unsaturated fatty acids (MUF As), polyunsaturated fatty acids (PUFAs), ro3 (omega 3) and ro6 (omega 6). There are 20 fatty acid was detected in /sognomom sp., 21 in A. ova/is and 22 in P. expansa. The saturated fatty acid (SAF As) has the highest concentration of fatty acids in tissues, sediments and suspended materials (14.5536 µg g- 1 , 4.1209 µg g- 1 and 95.7265 µg g- 1 ) compare to other form of fatty acid. The food sources that were indicated by fatty acids of bivalves that have studied are bacteria, mangrove detritus, macroalgae and microalgae. The fatty acids that indicate as bacteria sources (MUFAs) have the highest concentration (2.4630 µg t1 ) which is in Isognomom sp.compare with other sources.