Scorpions successfully inhabit some of the most arid habitats on earth. During exposure to desiccating stress water is mobilized from the scorpion hepatopancreas to replenish the hemolymph and retain hydration and osmotic stability. Carbohydrate catabolism is advantageous under these conditions as it results in high metabolic water production rate, as well as the release of glycogen-bound water. Hypothesizing that metabolic fuel utilization in scorpions is regulated in order to boost body water management under stressful conditions we used a comparative approach, studying energy metabolism during prolonged desiccation in four species varying in resistance performance. We used respirometry for calculating respiratory gas exchange ratios, indicative of metabolic fuel utilization, and measured metabolic fuel contents in the scorpion hepatopancreas. We found that hydrated scorpions used a mixture of metabolic fuels (respiratory exchange rates, RER. ~. 0.9), but a shift towards carbohydrate catabolism was common during prolonged desiccation stress. Furthermore, the timing of metabolic shift to exclusive carbohydrate oxidation (RER not different from 1.0) was correlated with desiccation resistance of the respective studied species, suggesting triggering by alterations to hemolymph homeostasis.
|Number of pages||6|
|Journal||Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology|
|State||Published - Aug 2012|
Bibliographical noteFunding Information:
We would like to thank three anonymous reviewers whose comments helped improve an earlier version of this manuscript. This study was supported by Israel Science Foundation awards 1645/08 and 975/08 to EG, and by the Israeli Ministry of Foreign Affairs Cultural and Scientific Relations Division.
- Desiccation resistance
- Energy metabolism
ASJC Scopus subject areas
- Molecular Biology