Poikilothermic organisms experience trade-offs by differential physiological demands generated by temperature extremes. Many such organisms exhibit acclimatory effects, adjusting their metabolism and physiology to recently experienced temperatures. One such acclimatory effect is metabolic compensation, the deceleration of biological rates below Arrhenius expectations. Daphnia magna is eurythermal, and if acclimated to mildly stressful temperatures first, survives longer in lethal temperatures. This study examined the effect of ambient temperature (5°C-37°C) and acclimation history (lifetime at 10°C or 25°C) on the oxygen consumption rates of 8 genotypes of Daphnia with high or low acute temperature tolerance. There were decelerations of respiratory rates across a temperature gradient when acclimated to 25°C or following short 8- hour acclimation to measurement temperatures. Daphnia exposed to a near-lethal temperature (35°C) with a 24-hour recovery period at 25°C-acclimation temperature showed no difference in respiratory control compared to unexposed 25°C-acclimated Daphnia. Genotypes showed no difference in potential compensatory ability.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etd-4856 |
| Date | 01 May 2018 |
| Creators | Coggins, Bret L |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Language | english |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations |
| Rights | Copyright by the authors. |
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