Stable isotopic differences (δ13C and δ15N) between muscle and fin ray tissues from juvenile Atlantic goliath grouper Epinephelus itajara (Lichtenstein, 1822) using non-lethal sampling.

Abstract

The Atlantic goliath grouper (Epinephelus itajara) is the largest species of grouper in the Atlantic Ocean and is classified as critically endangered in Brazil. This study compared the isotopic ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) between the muscle tissue and dorsal-fin rays of 37 juveniles to assess fin rays as a non-lethal alternative to muscle tissue sampling. The δ¹³C values in rays were significantly higher than those found in muscle, whereas the δ¹⁵N values did not differ significantly between tissues. Both stable isotopes showed high Spearman correlation coefficients (>0.80) between tissues. Thus, the study can enhance future research and broaden the application of stable isotope techniques in a non-lethal manner.