Isotopic determination of Japanese scallop Patinopecten (Mizuhopecten) yessoensis (Jay) tissues shows habitat-related differences in food sources

Using stable isotope analysis. this study examined the potential food sources of the Japanese scallop, Patinopecten (Mizuhopecten) yessoensis (Jay) and determined whether the isotopic ratios inferred from tissues of cultured scallops varied according, to Culture systems (hanging and sowing). Different tissues (i.e., muscle, ctenidia, and digestive gland) of scallops nesting in Saloma Lake (18.3-113.0 mm shell height) and Tokoro (66.8-121.4 mm shell height) and their potential food sources were analyzed for stable carbon and nitrogen isotope ratios. Average isotope ratios obtained in scallop muscle and ctenidia (-20.6 and -21.0 degrees(infinity) for delta C-13: 3.3 and 3.0 parts per thousand for delta N-15) from Tokoro area (sowing Culture; similar to 65 in depth) had close affinities to Suspended particulate organic matter (-21.6 parts per thousand and 2.7 parts per thousand for delta C-13 Lind delta N-15, respectively) suggesting that the scallops from Tokoro area depends oil detritus as in important food Source. Saloma Lake (hanging Culture; similar to 20 m depth) scallop muscle and ctenidia tissues however had relatively enriched delta C-13 values (-17.7 and -18.1 parts per thousand) and were relatively closer to either net plankton (-21.1 parts per thousand) and particulate organic matter (-22.1 parts per thousand) delta N-15 values were also higher in particulate organic matter taken in Saloma Lake (5.0 parts per thousand) and showed a 5.1 parts per thousand difference when muscle tissues in two sites are compared. Digestive gland tissues however showed depleted delta C-13 and delta N-15 signatures relative to other tissues in both systems. The observed variations in isotopic ratios in scallops rea red in two systems thus reflect differences in carbon and nitrogen sources related to culture habitats.