Behavioral substrate choice experiments in a tropical cryptic crab

Observational data on substrate choice experiments in the crab Oocypode pallidul

Microsatellite Data of Yellow and White-collared Manakins in Mixed Leks

Microsatellite Data of Yellow and White-collared Manakins in Mixed Lek

Mean (+1SE) (A) color contrast (Δ<i>S</i>) and (B) luminance contrast (<i>L</i>) as viewed through the hexachromatic visual system of <i>Poecilia parae</i>.

<p>Female and male color phenotypes with different letters are significantly different at P<0.01 (Fisher LSD post-hoc comparisons). Error bars represent 95% confidence intervals.</p

Mean (+1SE) (A) color contrast (Δ<i>S</i>) and (B) luminance contrast (<i>L</i>) as viewed through the trichromatic visual system of <i>Aequidens tetramerus</i>, a common cichlid predator.

<p>Female and male color phenotypes with different letter are significantly different at P<0.01 (Fisher LSD post-hoc comparisons). Error bars represent 95% confidence intervals.</p

Variation in the Visual Habitat May Mediate the Maintenance of Color Polymorphism in a Poeciliid Fish

<div><p>The conspicuousness of animal signals is influenced by their contrast against the background. As such, signal conspicuousness will tend to vary in nature because habitats are composed of a mosaic of backgrounds. Variation in attractiveness could result in variation in conspecific mate choice and risk of predation, which, in turn, may create opportunities for balancing selection to maintain distinct polymorphisms. We quantified male coloration, the absorbance spectrum of visual pigments and the photic environment of <i>Poecilia parae,</i> a fish species with five distinct male color morphs: a drab (i.e., grey), a striped, and three colorful (i.e., blue, red and yellow) morphs. Then, using physiological models, we assessed how male color patterns can be perceived in their natural visual habitats by conspecific females and a common cichlid predator, <i>Aequidens tetramerus</i>. Our estimates of chromatic and luminance contrasts suggest that the three most colorful morphs were consistently the most conspicuous across all habitats. However, variation in the visual background resulted in variation in which morph was the most conspicuous to females at each locality. Likewise, the most colorful morphs were the most conspicuous morphs to cichlid predators. If females are able to discriminate between conspicuous prospective mates and those preferred males are also more vulnerable to predation, variable visual habitats could influence the direction and strength of natural and sexual selection, thereby allowing for the persistence of color polymorphisms in natural environments.</p></div

Mean (A) irradiance and (B) radiance spectra characterizing the sampling habitats in the east (solid line) and west (dotted line) populations where <i>P. parae</i> and their predators are found.

<p>Mean (A) irradiance and (B) radiance spectra characterizing the sampling habitats in the east (solid line) and west (dotted line) populations where <i>P. parae</i> and their predators are found.</p

Example of the absorbance spectra for visual pigments of the cone photoreceptor cells of <i>Poecilia parae</i>.

<p>The best fitting templates (open circles) used to estimate the λ_max values of the pigments are shown overlaying the absorption curves.</p

Differences in the perceived chromatic contrast between the two most conspicuous males as perceived by a common predator across different sampling sites in the (A) east and (B) west populations.

<p>Differences were calculated by subtracting the Δ<i>S</i> values of the most conspicuous color morphs from the Δ<i>S</i> values of the second most conspicuous morph at each sampling site. Upper half of each circle represents the most conspicuous male color morph, while the lower half represents the second most conspicuous color morph at each site. Blue, red, yellow, immaculata and parae male color morphs are represented by blue, red, yellow, gray and magenta colors, respectively.</p

Mean (±1SE) reflectance of (A) female, and immaculata and parae males, and (B) blue, red and yellow males.

<p>Reflectance curves are from the means of 5 females and 5 males of each color morph.</p

Significant predictors of morph frequency across sampling sites in <i>Poecilia parae.</i>

<p>Note: Each model was constructed using backward stepwise multiple regression analysis with color and luminance contrasts as determined for conspecifics, color and luminance contrast as determined for predators, and the relative abundance of <i>Aequidens tetramerus</i> cichlid predator as independent variables. Standardized regression coefficients (β') and significance tests are shown for each significant predictor variable. Normality Test (Shapiro-Wilk) P>0.46.</p