Meeting Abstract

P3.165  Monday, Jan. 6 15:30  Nest soil moisture and incubation temperature influences on visceral organ mass in snapping turtle (Chelydra serpentina) neonates FINKLER, M.S.*; HOLDA, J.; CATT, B.; Indiana University, Kokomo mfinkler@iuk.edu

We investigated whether variation in moisture availability and temperature during incubation influenced the relative size of visceral organs of hatchling snapping turtles. Snapping turtle eggs were incubated at three different temperatures (25, 27.5, and 30 °C) in natural soil collected from original nest sites with water contents adjusted to either 5% or 7% water by mass. Hatchlings were sacrificed at Day 5 post-hatching, their yolk sacs, hearts, livers, lungs, stomachs small intestines and kidneys were removed, and the organs and remainder of the carcass were dried to a constant mass. Hatchlings from eggs incubated in the wetter soil were larger than those from eggs incubated in the drier soil, but had relatively smaller hearts and livers based on dry mass. The relative dry masses of the yolk sac, lungs, and kidneys did not differ among the two soil moisture treatments. Dry carcass mass and the relative sizes of the heart, liver, lungs, and yolk sac were similar among incubation temperature treatments. However, the relative dry mass of the kidneys were larger in hatchlings incubated at 25 °C than at hatchlings from the two higher temperatures. The relative dry masses of the stomach and small intestine were greater in hatchlings from the drier soil treatment incubated than in those from the wet treatment at 30 °C, but were similar between the two moisture treatments at the other two temperatures. The findings suggest that for eggs incubated in natural soils variation in water availability in particular may influence relative organ size, perhaps through alterations in circulation and mobilization of nutrients, whereas incubation temperature appears to induce little difference in the relative size of visceral organs.