Meeting Abstract

31-3  Thursday, Jan. 5 14:15 - 14:30  Effects of varying temperature during early development on hatching size in Chelydra serpentina. FINKLER, M.S.; FINKLER, Michae; Indiana Univ. Kokomo mfinkler@iuk.edu http://www.indiana.edu/~nimsmsf/

Turtle embryos may experience different thermal conditions during different stages of incubation, but laboratory studies frequently incubate eggs under single constant temperatures for the entirety of development. When incubated under single constant temperatures, increased temperature leads to earlier hatching and smaller body sizes in snapping turtle (Chelydra serpentina) neonates. In this study, I incubated snapping turtle eggs at three different temperatures (23, 25, and 27 °C) for the first 21 days of incubation, then transferred the eggs to a constant 25 °C for the remainder of development. Dry embryo mass at Day 21 was highest in the 27 °C group and lowest in the 23 °C group, and dry egg content mass at Day 21 was significantly higher for eggs incubated at 23 °C than those incubated at higher temperatures. Mean incubation durations for the 23, 25, and 27 °C early incubation temperatures were 78.1, 74.3 and 66.3 days respectively. Carcass masses and carapace lengths were larger, and yolk sacs were smaller, in hatchlings exposed to 27 °C early in development than those exposed to the two lower temperatures. My findings indicate that temperature variation during early embryonic development can have lasting effects on growth patterns during the remainder of development, with higher temperatures during early development promoting increased growth during this period.