Figure legends
Fig.1 Sites for the collection of samples from ten lochs in North Uist
and eight lochs in South Uist, Scotland (A. Map of United Kingdom B.
Loch position in North Uist C. Loch position in South Uist with road
map).
Fig. 2 The first two PCs of body armour traits for anadromous
sticklebacks collected from North (Ash, circle) and South (orange,
triangle) Uist. Traits were plate count and residual values (from body
length) of 1st dorsal spine length (X1st.DSL),
2nd dorsal spine length (X2nd.DSL), pelvic spine
length (PSL), length of pelvis (LPS), height of pelvis (HPS). PC1
(35.2%) describes overall variation in armour, with positive loadings
of all variables. PC2 (22.75%) mainly describes variation in plate
count (positive loading), but also reflects negative loadings for LPS
and PSL. Ellipses represent 95% confidence levels within each data set.
Fig. 3 Mean standard length (± S.E.) of anadromous and resident fish
shows little overall variation in size between North (Ash, circle) and
South Uist (orange, triangle) sticklebacks. Resident stickleback of
North and South Uist were significantly smaller than the anadromous
fish.
Fig. 4 A. The first two principal components (PCs) of six body armour
traits and standard length for resident stickleback of North Uist
(circle) and South Uist (triangle). PC1 (71.3%) describes overall
variation in spine length and pelvic size, while PC2 (13.8%) describes
variation in plate number. B. Correlogram showing correlations between
all measured armour traits including plate count, PC1, PC2 and standard
length of North and South Uist resident fish. Blue colour denotes
positive correlations where shade of the square box indicates the
strength of the correlation. Measured traits were: 1stdorsal spine length (X1st.DSL), 2nd dorsal spine
length (X2nd.DSL), pelvic spine length (PSL), length of pelvis (LPS),
height of pelvis (HPS). Ellipses with 95% confidence intervals for each
data set describing variation in four pH groups of loch water,
separating the larger cluster for samples in freshwater low pH fish than
the other groups.
Fig. 5 A-F Mean (± S.E.) plate count (A) and standard length (B-F) of
five armour traits in 18 freshwater stickleback populations on North
(circle) and South Uist (triangle).