Interspecific and Regional Variation in Otolith Chemical Signatures Between Juvenile Red and Lane Snappers in the Northern Gulf of Mexico

Otolith chemical signatures (Ba:Ca, Mg:Ca, Mn:Ca, Sr:Ca, Li:Ca, δ¹³C and δ¹⁸O) of juvenile red and lane snapper species were compared among three regions in the Gulf of Mexico (Alabama/Mississippi; Louisiana; and Texas) to test if signatures from lane snapper could be used as a proxy for red snapper signatures. A two factor multivariate analysis of variance (MANOVA), with species and region main effects, was computed to test for regional and interspecific differences, while analysis of variance (ANOVA) models were computed to test for the same differences in individual constituents. Signatures were significantly different among regions (MANOVA, p < 0.001) and between species nested within region (MANOVA, p < 0.001). Among constituents, Li:Ca, Ba:Ca, Sr:Ca, δ¹³C, and δ¹⁸O were significantly different between species (ANOVA, p < 0.05). These significant interspecific differences in otolith chemical signatures indicate that lane snapper otolith chemistry does not serve as an accurate proxy for red snapper signatures.