Growth rate, body size, sexual dimorphism and morphometric variation in four populations of painted turtles (Chrysemys picta bellii) from Nebraska

I studied variation in individual growth rate, body size, sexual size dimorphism and morphometry in two sandhill lake and two Platte River floodplain populations of painted turtles from western Nebraska. Individual growth rate of juveniles and mean adult body size were greater in the sandhills populations than in the floodplain populations. Comparisons of mean individual growth rates of juveniles reported here and mean population egg size reported for these populations in an earlier study support predictions for the evolution of offspring size. Females were larger than males and sexual dimorphism was greatest in populations with relatively slow individual growth rates, a pattern that is inconsistent with the findings for other local populations of painted and closely related slider turtles. Body size-adjusted carapace width, shell height and plastron length varied significantly within and between sexes and populations. Interpopulational variation in shell width and height are hypothesized to be related to variation in clutch frequency or to differences in hydrodynamics between lake and riverine systems