Data accompanying Polyphenisms and polymorphisms: genetic variation in plasticity and color variation within and among bluefin killifish populations

The presence of stable color polymorphisms within populations begs the question of how genetic variation is maintained.  Consistent variation among populations in coloration, especially when correlated with environmental variation, raises questions about whether environmental conditions affect either the fulcrum of those balanced polymorphisms, the plastic expression of coloration, or both.  Color patterns in male bluefin killifish provoke both types of questions.  Red and yellow morphs are common in all populations.  Blue males are more common in tannin-stained swamps relative to clear springs.  Here we combined crosses with a manipulation of light to explore how genetic variation and phenotypic plasticity shape these patterns.  We found that the variation in coloration is attributable mainly to two axes of variation: (1) a red-yellow axis with yellow being dominant to red, and (2) a blue axis that can override red-yellow and is controlled by genetics, phenotypic plasticity, and genetic variation for phenotypic plasticity. The variation among populations in plasticity suggests it is adaptive in some populations but not others. The variation among sires in plasticity within the swamp population suggests balancing selection may be acting not only on the red-yellow polymorphism but also on plasticity for blue coloration.

Methods
There are two primary data sets here.

Data set #1: Color morph frequences across treatments:

In this study, we conducted a series of crosses between males and females from a spring and a swamp population. For each population, we attempted to get 2 males that were represented of 4 major color patterns (see column 8). We also attempted to cross the male with two separate dams (usually denoted as dam a and dam b). For each sire-dam combination, we sought to obtain 50 eggs which were divided between two tanks: one with clear water that mimicked springs and the other with tea-stained water that mimicked swamps.  We raised the individuals to adulthood and scored them for coloration. From these, we examined the effects of cross, male color pattern, and water treatment (i.e., lighting environment) on the expression of male coloration.

Data Set #2: Downwelling irradiance data:

Downwelling irradiance spectrum from the Everglades site (26 Mile Bend) and the Wakulla River.  Spectra were collected in May and June 2017 with an Ocean Optics S2000 spectrophotometer.  The spectrophotometer was calibrated with a deuterium-halogen light source. Spectra were taken with an Ocean Optics cosine-corrector attached to a patch cord. Multiple spectra were taken slightly above the water surface (0 cm), slightly below the water surface (1 cm) and at 38 cm depth.  Measurements were taken at sunny conditions in the mid-morning. Replicate spectra were averaged at for each combination of depth and population.