The Influence of Incubation Temperature and Family on Eggs, Embryos, and Hatchlings of the Smooth Softshell Turtle (Apalone mutica)

Abstract

I incubated eggs of the smooth softshell turtle (Apalone mutica) at 26°, 28°, and 30° C in 2 yr to investigate the physiological significance of temperature on developing embryos and hatchlings. In particular, I tested the hypothesis that temperature has a direct effect on physiology of developing embryos independent of the hydric environment, specifically as expressed through its effects on hatchling size and locomotor performance. Hatching success was lowest at 26°C but did not differ significantly among treatments or between years. Survivorship of turtles to 2 wk posthatching varied significantly among temperature treatments, because relatively few individuals from 26°C survived Duration of incubation was negatively related to incubation temperature. However, sex determination of hatchling turtles was independent of incubation temperature. All but one measure of body size of turtles varied positively with incubation temperature in both years, which suggests that temperature directly affected embryonic ...