Table of Contents
ISRN Zoology
Volume 2012 (2012), Article ID 846136, 13 pages
http://dx.doi.org/10.5402/2012/846136
Research Article

Interspecific Variation in Temperature Effects on Embryonic Metabolism and Development in Turtles

1Department of Zoology, Oklahoma State University, Stillwater, OK 74078, USA
2Department of Biology, Missouri State University, 901 South National, Springfield, MO 65897, USA

Received 22 November 2011; Accepted 25 December 2011

Academic Editors: P. V. Lindeman and P. Scaps

Copyright © 2012 Day B. Ligon and Matthew B. Lovern. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We measured temperature-induced differences in metabolic rates and growth by embryos of three turtle species, Macrochelys temminckii, Trachemys scripta, and Apalone spinifera, at different, constant, temperatures. Oxygen consumption rate (VO2) was measured during development and used to characterize changes in metabolism and calculate total O2 consumption. Results from eggs incubated at different temperatures were used to calculate Q10s at different stages of development and to look for evidence of metabolic compensation. Total O2 consumption over the course of incubation was lowest at high incubation temperatures, and late-term metabolic rate Q10s were <2 in all three species. Both results were consistent with positive metabolic compensation. However, incubation temperature effects on egg mass-corrected hatchling size varied among species. Apalone spinifera hatchling mass was unaffected by temperature, whereas T. scripta mass was greatest at high temperatures and M. temminckii mass was lowest at high temperatures. Hatchling mass : length relationships tended to correlate negatively with temperature in all three species. Although we cannot reject positive metabolic compensation as a contributor to the observed VO2 patterns, there is precedence for drawing the more parsimonious conclusion that differences in yolk-free size alone produced the observed incubation temperature differences without energetic canalization by temperature acclimation during incubation.