Figure 3. Dosidicus gigas latitudinal variation in δ¹⁵N values (‰).

(A) Latitudinal variation in bulk δ¹⁵N values (n = 45) from muscle and (B) amino acid compound specific data from composite muscle samples. Sample size for each composite sample in a given stations is: n = 3 squid for stations 1, 2 and 5; n = 2 squid for station 3; n = 1 squid for station 4. Mean and one standard deviation are shown for Phenylalanine (the main source amino acid;⧫), Glutamic acid (the main trophic amino acid; ▪), and bulk (▴) δ¹⁵N. Dashed lines indicate linear regressions: (A) δ¹⁵N_bulk, r² = 0.14, p<0.01; (B) δ¹⁵N_{Glutamic acid}, p = 0.4 and δ¹⁵N_{Phenylalanine}, p = 0.1.