Stable isotopic fingerprints of genuine and "bathing" cultured Chinese mitten crabs (Eriocheir sinensis) in Yangcheng Lake, China

The isotopic ratios of C, N, H, and O (i.e., delta 13C, delta 15N, delta 2H, and delta 18O) in the third pereiopods of genuine and onemonth "bathing" cultured foreign Chinese mitten crabs (Eriocheir sinensis) were analyzed to distinguish between them in Yangcheng Lake. The isotopic fingerprints were clarified using one-way analysis of variance, principal component analysis (PCA), and linear discriminant analysis (LDA). PCA accurately distinguished Yangcheng Lake crabs from "bathed" crabs based on their C, N, H, and O isotopic profiles before or after bathing. Similarly, the LDA of the chemometric fingerprints showed good performance for accurate discrimination between the genuine and "bathed" crabs. This study successfully identified "bathed" crabs, showing that foreign crabs cannot acquire the isotopic "fingerprint" of genuine Yangcheng Lake crabs, even after only a short bathing period. Stable isotopic fingerprints have potential applications in distinguishing "bathed" crabs from Yangcheng Lake crabs.