Fig. 4

Phenotypic features of the three pike lineages (blue: Northern, red: Circumpolar, green: Southern). SL—Standard lengths (A), HL/SL—Head length in the proportion of Standard Lengths (B), PA / SL—Preanal distances in the proportion of the Standard Length values (C), PPL / SL—Prepelvic distances in the proportion of the Standard Length valuess (D), PPEC / SL—Prepectoral distances in the proportion of Standard Lengths (E), PRE / HL—Preorbital distances in the proportion of the Head Length values (F), ED / HL—Eye diameter in the proportion of the Head Length values (F) and the number of scales on the lateral line (H). Each box represents the 25% and 75% quartiles of the dataset, the band in the box is the median. The whiskers are drawn from the top of the box up to the largest data point less than 1.5 times the box height from the box (the"upper inner fence"), and similarly below the box. Values outside the inner fences are shown as circles values further than three times the box height from the box (the "outer fences") are shown as black stars. Datasets marked by red asterisk differ significantly from the others by the results of non-parametric Kruskal–Wallis pairwise comparisons (p˂0.05). Colour figure online