Morphology
Morphological variation was low among the four dietary groups within the piscivorous ecotype. The first canonical axis for body shape CVA was significant (P > 0.05), but head shape CVA revealed no significant canonical axes (P > 0.05) in groupings (Fig. 5 a, b, c). MANOVAs for body and head shape were not significant (P > 0.05). Linear measurements CVA revealed one significant canonical axis (P > 0.05). MANOVA permutation tests confirmed differences in linear measurements among groups (P = 0.047). Most distinctions were related to linear measurements of heads, with upper and lower jaws, head depth, and snout-eye lengths differing between Group 3 and Group 4 (P ≤ 0.05), and head length differing between Group 1 and 4 (P = 0.03; Fig. 6). Caudal peduncle length and anal fin length differed marginally between Groups 2 vs 3 (P = 0.068) and Groups 1 vs 3 (P = 0.075), respectively. The first two PCA axes explained 44.3% and 12.3 % of variation for body shape, 35.1% and 30.7 % of variation for head shape, and 39.6 % and 20.9 % for linear measurements (Fig. 5 d, e, f).