open access

https://hdl.handle.net/2115/65190

Isotopic trophic-step fractionation of the freshwater clam Corbicula sandai

英語

Laboratory experiment

2016-05

Springer

Fisheries science

82(3)

491-498

Diet-switch experiments with three different species of microalgae were conducted to estimate diet-tissue isotopic fractionation of carbon (C) and nitrogen (N) isotopes in the freshwater clam Corbicula sandai. The delta C-13 and delta N-15 values in the soft tissues of C. sandai changed in each experiment, with little inter-individual deviations, thereby reflecting the switch in diet. Isotope values of the clam reached the asymptotic value at around 40 days after the switch. Equilibrium isotopic signatures, as well as turnovers of carbon and nitrogen in the whole soft tissues, were estimated by exponential decay models. Fractionations for C. sandai varied from 0.1 to 0.7 aEuro degrees for carbon, and from 2.1 to 3.6 aEuro degrees for nitrogen; these values fell within or were close to the range of previously accepted fractionation values (0-1 aEuro degrees for carbon and 3-4 aEuro degrees for nitrogen). The half-life values for carbon in the bivalves (12-22 days) were about twofold longer than those for nitrogen (7-9 days). The specific fractionation values estimated in this study contribute towards improving our understanding of inter-specific trophic relationships and aquatic food webs.

学術雑誌論文

Accepted Manuscript

The final publication is available at www.springerlink.com via http://dx.doi.org/10.1007/s12562-016-0970-3

0919-9268

AA10993718