Fig 1.
(a) Lingcod (Ophiodon elongatus) of two color morphs: blue (topmost and fourth-from-top) and brown (second-from-top, third-from-top, and bottommost). (b) Blue coloration affects both external and internal tissues. Courtesy of Laurel Lam / NOAA.
Fig 2.
Map of study region with sampling sites indicated.
Sites where any blue male (total n = 4) was collected are indicated in blue; sites that yielded only brown males are indicated in brown. The depth of collection of each blue male is noted (in meters). (a) Full study extent with insets displaying the boundaries of maps (b), (c), and (c). Sampling sites in (b) Alaska, (c) Puget Sound, Washington, (d) northern and southern California. Site locations in Puget Sound are jittered to allow better visualization of nearby sites.
Fig 3.
(a) Total number of lingcod individuals sampled of each sex (male versus female) and each color (blue versus brown). Effect of color (blue versus brown) and sex (male versus female) on (a) parasite abundance of the average parasite taxon per lingcod individual, (b) Fulton’s K condition factor (i.e., ratio of weight to cubed length), and (d) hepatosomatic index, where data represent predicted (fitted) values for the response of parasite abundance to color and sex, computed while keeping all other factors (including random effects) in the model constant using the ggeffects() function in the ggeffects package in R [44]. For (b), (c), and (d), points are slightly jittered in the x-dimension to allow visualization of overlapping error bars.
Table 1.
Results of generalized linear mixed model for parasite burden across all parasite taxa.
Fig 4.
Random slopes for each parasite taxon’s response to the host color * sex interaction, from GLMM for parasite abundance.
The across-parasite-taxa fixed effect of the interaction term is indicated with a dotted vertical line. A negative sex * color interaction indicates that the difference in parasite burden between blue and brown males is greater than the difference in parasite burden between blue and brown females; in other words, the more negative the interaction, the more parasites blue males carry compared to all other sex–color combinations.
Table 2.
Results of general linear mixed models for (a) Fulton’s K and (b) hepatosomatic index.
(a) Fulton’s K (n unique fish hosts = 2087, n sampling locations nested within sampling regions = 87, and n sampling regions = 7). (b) hepatosomatic index (n unique fish hosts = 2076, n sampling locations nested within sampling regions = 87, and n sampling regions = 7).