Figure 12

Carbon and nitrogen isotopic compositions of individual organs from various animal samples. These are shown as differences relative to the isotopic composition of muscle (i.e., Δ ¹³C = δ ¹³C_tissue − δ ¹³C_muscle, and Δ ¹⁵N = δ ¹⁵N_tissue − δ ¹⁵N_muscle). The letters next to the symbols are abbreviations of the organs or tissues. All institutional and national guidelines for the care and use of laboratory animals were followed.