Torres-Dowdall etal. BJLS 2555.R1. Phenotypic data

Data used in the analysis of phenotypic variation observed in wild-caught fish of Poecilia reticulata and Poecilia picta (‘Species’ column). Phenotypes measured in males include size and condition index (Kn). Phenotypes measured in females include reproductive allocation, fecundity, mean size of developing embryos, and condition index (Kn). ‘ID’ indicates internal collection number. ‘Sex’ specifies if data was collected from a male or a female. ‘Drainage’ refers to the drainage from where wild fish were collected. ‘Locality’ refers to the place along each drainage from where fish were collected (‘Upstream’ correspond to a freshwater-upstream locality where only P. reticulata occurred, ‘Midstream’ to a freshwater-midstream locality where both species were present, and ‘Downstream’ to a brackish water-downstream locality where only P. picta occurred). Size was measured as standard length of the fish (‘Length’ column, units in millimeters). Adult mass is presented as eviscerated dry mass (‘Mass’ column, units milligrams). ‘Kn’ refers to condition index, which was determined using this formula (Kn= Mi/aLib); where (a) is the intercept and (b) the slope of the least squares regression of log-transformed individual dry mass (Mi) on log-transformed individual standard length (Li). ‘#_Embryos’ was used to determine fecundity, and is a measure the number of developing embryos found in a female at the time of euthanasia. ‘Mean_offspring_mass’ is a measure of the size of each developing embryo at the time of the female’s euthanasia. ‘Reproductive_allocation’ is a measure of the percentage of the mass of a female dedicated to reproduction. ‘Mean_Stage’ is a measure of the developmental stage in which the embryos were at the time of the female’s euthanasia. Missing data or not corresponding data are showed as a dash.