Data from: When phenotypes do not match genotypes – unexpected phenotypic diversity and potential environmental constraints in Icelandic stickleback

Divergent lateral plate phenotypes in stickleback represent one of only a few cases known where a single gene underlies the phenotype under divergent selection between different habitats. However, the selection pressures leading to the repeated loss of lateral plates in freshwater are still not well understood. By genotyping 838 individuals from nine independently colonized lakes and one marine population in Iceland, we found i) that only in some lakes are phenotypes associated with the expected genotype and ii) that the independent repeated occurrence of a rarely described plate phenotype is expressed in the absence of an allele that is usually associated with this phenotype. This suggests that either other genes such as modifiers might be under divergent selection between lakes or that lateral plate expression in these populations is restricted due to environmental constraints.Lateral plate counts and EDA STN382 allel numberIndividual based data providing the name of the lake sampled (Lake), an identifier for each individual (Individual), the number of later plates counted on the left side on the keel (Keel), the number of STN382 C alleles (STNallele), the total number of lateral plates counted on the left side (Total_Plates) and the assigned phenotypic morph (Morph). Plate morph abbreviations are as follow: LP - low plated with 10 or less anterior plates, LPK - as LP but with plates on the keel, PPNK - partial plated, i.e. having > 10 plates but no plates on the keel, PPK - as PPNK but with plates on the keel, FP - fully plated with plates continuously along the left sidedryad.tx