Acute and Persistent Effects of Pre- and Posthatching Thermal Environments on Growth and Metabolism in the Red-Eared Slider Turtle, Trachemys scripta elegans
Many ectotherms possess the capacity to survive a wide range of thermal conditions. Long-term exposure to temperature can induce acclimational and/or organizational effects, and thedevelopmental stage at which temperature exposure occurs may affect the type, degree, andpersistence of these effects. We incubated red-eared slider turtle embryos at three differentconstant temperatures (Tinc; 26.5, 28.5, 30.5°C), then divided the resulting hatchlings betweentwo water temperatures (Twater; 25, 30°C). We calculated growth rates to assess the short- and long-term effects of thermal experience on this metabolically costly process. We also measuredresting metabolic rate (RMR) at three body temperatures (Tbody; 26.5, 28.5, 30.5°C) shortly afterhatching and 6 months posthatching to characterize the degree and persistence of acclimationto Tincand Twater. Hatchling RMRs were affected by Tbody and Tinc, and fit a pattern consistentwith positive but incomplete metabolic compensation to Tinc. Average growth rates over the first 11 weeks posthatching were strongly affected by Twater but only marginally influenced by Tinc, and only at Twater= 30°C. Six-month RMRs exhibited strong acclimation to Twater consistent with positive metabolic compensation. However, within each Twater treatment, RMR fits patterns indicative of inverse metabolic compensation to Tinc, opposite of the pattern observed in hatch-lings. Average growth rates calculated over 6 months continued to show a strong effect of Twater, and the previously weak effect of Tinc observed within the 30°C Twatertreatment became more pronounced. Our results suggest that metabolic compensation was reversible regardless ofthe life stage during which exposure occurred, and therefore is more appropriately consideredacclimational than organizational.
Ligon, Day B., Charles C. Peterson, and Matthew B. Lovern. Acute and Persistent Effects of Pre- and Posthatching Thermal Environments on Growth and Metabolism in the Red-Eared Slider Turtle, Trachemys scripta elegans. "Journal of Experimental Zoology Part A: Ecological Genetics and Physiology" 317, no. 4 (2012): 227-235.
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