Standard major axis regression results (mean and 95% confidence intervals for species-specific intercepts and slopes) for pairwise relationships between key diet components and stable isotope ratios within individual fish, with associated test statistics and P-value for likelihood ratio test (LR; χ², 2 d.f.) for equality of slopes bolded and italicized when significant.

Species-specific relationships are bolded and italicized when a within-species correlation test was significant; differences among species were assessed via overlapping confidence intervals. See visualization of significant relationships in Fig 1. Significance was determined at a corrected P < 0.0009.