Diet-tissue discrimination factors (Δ13C and Δ15N) and turnover rate in somatic tissues of a neotropical detritivorous fish on C3 and C4 diets

In this study, diet‐tissue discrimination factors and turnover rates were determined from the somatic tissues of a detritivorous fish Prochilodus lineatus. The carbon (Δ13C) and nitrogen (Δ15N) diet‐tissue discrimination factors varied for all feed rations with a range of Δ13C values between −1·9 and 3·6‰ and Δ15N between 3·3 and 5·7‰. Carbon turnover rate in the blood was 23·1 days for the C3 ration and 34·7 days for the C4 ration, in the liver was 9·9 days under the C3 ration and nitrogen turnover rate was the same (23·1 days) in the liver for both C4 and C3–C4 rations, and 13·9 days in the muscle for C3–C4 ration.