GROWTH-RATE, BODY-SIZE, SEXUAL DIMORPHISM AND MORPHOMETRIC VARIATION IN 4 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 f loodplain populations of painted turtles from western Nebraska. Indivi dual growth rate of juveniles and mean adult body size were greater in the sandhills populations than in the floodplain populations. Compari sons of mean individual growth rates of juveniles reported here and me an population egg size reported for these populations in an earlier st udy support predictions for the evolution of offspring size. Females w ere larger than males and sexual dimorphism was greatest in population s with relatively slow individual growth rates, a pattern that is inco nsistent with the findings for other local populations of painted and closely related slider turtles. Body size-adjusted carapace width, she ll 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.