Validating fin tissue as a non-lethal proxy to liver and muscle tissue for stable isotope analysis of yellow perch (Perca flavescens)

Stable isotope ecology typically involves sacrificing the animal to obtain tissues. However, with threatened species or in long-term longitudinal studies, non-lethal sampling techniques should be used. The objectives of this study were to (1) determine if caudal fin tissue could be used as a non-lethal proxy to liver and muscle for stable isotope analysis, and (2) assess the effects of ethanol preservation on N-15 and C-13 in fin tissue of juvenile yellow perch Perca flavescens. The C-13 of caudal fin was not significantly different from liver (t(23)=-0.58; p=0.57), and was more correlated with N-15 in liver (r(2)=0.78) than muscle (r(2)=0.56). Ethanol preservation enriched N-15 and C-13 for caudal fins, but by using our developed regression models, these changes in N-15 and C-13 can now be corrected. Overall, caudal fin tissue is a more reliable proxy to liver than muscle for N-15 and C-13 in yellow perch.