Fig 1.
Geographic location of Mistassini Lake, Québec, Canada and colour frequency, depth distribution and basin preferences of each one of the genetically-demarcated clusters.
(A) Shown on the map are 24 hr gillnet sets (star) and lake sector (W1–6 and E7–12) divided by dashed lines. (B) Frequency of colours observed in each genetically-demarcated lake trout clusters in Mistassini Lake. (C) Depth distribution of lake trout in each one of the genetically-demarcated clusters. Beanplot shows accurate densities and the red line indicates the median. (D) Basin preferences of lake trout in each one of the genetically-demarcated clusters. Results of a generalized linear model (GLM) that took into account the fishing effort and demonstrates that clusters 1 and 5 were caught in higher numbers in the eastern basin and clusters 3 and 4 were caught in higher numbers in the western.
Fig 2.
Spatial principal component analysis of lake trout showing the first global structure across Mistassini Lake.
Plotted are the lagged scores in which colours (blue to red) represent the score of an individual genotype; each is positioned by its spatial coordinates. Inset is the barplot for all eigenvalues (A), and the screen plot (B) which illustrates the spatial and variance components of those eigenvalues.
Fig 3.
Association between morphological clusters and genetically-differentiated clusters of lake trout present in Mistassini Lake.
Morphological clusters are identified by symbol shape and ellipses which represent 67% of that cluster’s variation and genetically-differentiated clusters are identified by symbol colour. (A) RW1 vs. 2 and 1 vs. 3 (55%) of body shape variation. Morphological shifts for RW1 (26%) correspond to the slope of the snout, lower jaw and dorsal and belly curvature; RW2 (17%) correspond to slope of top of cranium and dorsal side, length and depth of caudal peduncle; RW3 (12%) correspond to body depth, eye position and size. (B) RW 1 vs. 2 and 1 vs. 3 (71%) of head shape variation. Morphological shifts for RW1 (36%) correspond to length of head and snout, eye position and length of upper jaw; RW2 (23%) correspond to head depth and bluntness of snout; RW3 (12%) correspond to slope of lower and upper jaw. Inset images are visualizations of the shape at the most extreme end of each relative warp.
Fig 4.
Visualization of Mantel tests: genetic distance vs. morphological and ecological variables.
Shown are comparisons of genetic distance (pairwise FST) vs. (i) the absolute difference in mean relative warp (RW) score for the first two RWs for body (A, B) and head morphology (C, D); (ii) absolute difference in prey abundance (E); and (iii) the absolute difference in median depth (m) (F). Body RW1 and 2 represent 26% and 17% of the total variation; whereas head RW1 and 2 represent 36% and 23% of the total variation. The remaining visualizations of Mantel tests can be seen in Fig S8.4 in S8 File.
Table 1.
A comparison of lake physical attributes and sympatric differentiation of lake trout as currently described in the literature.
Fig 5.
Morphological variation among individual lake trout and across all genetically-demarcated clusters within Mistassini Lake, Québec.
Coloured circles and numbers represent the genetically-demarcated clusters that individual lake trout were assigned to.