ORIGINAL PAPER Adjustment of metabolite composition in the haemolymph to seasonal variations in the land snail Helix pomatia Annegret Nicolai • Juliane Filser • Roman Lenz • Carole Bertrand • Maryvonne Charrier Received: 23 June 2010 / Revised: 9 November 2010 / Accepted: 16 November 2010 / Published online: 7 December 2010 Ó Springer-Verlag 2010 Abstract In temperate regions, land snails are subjected to subzero temperatures in winter and hot temperatures often associated to drought in summer. The response to these environmental factors is usually a state of inactivity, hibernation and aestivation, respectively, in a temperature and humidity buffered refuge, accompanied by physiologi- cal adjustments to resist cold or heat stress. We investigated how environmental factors in the microhabitat and body condition influence the metabolite composition of haemo- lymph of the endangered species Helix pomatia. We used UPLC and GC–MS techniques and analyzed annual bio- chemical variations in a multivariate model. Hibernation and activity months differed in metabolite composition. Snails used photoperiod as cue for seasonal climatic varia- tions to initiate a physiological state and were also highly sensitive to temperature variations, therefore constantly adjusting their physiological processes. Galactose levels gave evidence for the persistence of metabolic activity with energy expenditure during hibernation and for high repro- ductive activity in June. Triglycerides accumulated prior to hibernation might act as cryoprotectants or energy reserves. During the last month of hibernation snails activated physiological processes related to arousal. During activity, protein metabolism was reflected by high amino acid level. An exceptional aestivation period was observed in April giving evidence for heat stress responses, like the protection of cells from dehydration by polyols and saccharides, the membrane stabilization by cholesterol and enhanced metabolism using the anaerobic succinic acid pathway to sustain costly stress responses. In conclusion, physiological adjustments to environmental variations in Helix pomatia involve water loss regulation, cryoprotectant or heatpro- tectant accumulation. Keywords Heat stress Á Cholesterol Á Polyols Á Triglycerides Á Galactose Á Hibernation Introduction Land snails are subjected to annual cycles of activity and dormancy in relation to seasonal changes in temperature and humidity, and therefore should be adapted with a range of behavioral and physiological mechanisms that will ensure their survival under their specific microhabitat conditions. In temperate regions, these ectothermic animals with continuously moist tegument encounter two opposite extreme climatic situations during the year: subzero tem- peratures in winter and hot temperatures, often associated with drought, in summer. The response to these environ- mental factors is usually a state of inactivity, hibernation and aestivation, respectively, in a temperature and humidity buffered refuge. In both dormancy states the body is fully withdrawn, and the shell is obturated by an epi- phragm (Ansart et al. 2002; Lind 1988). Both dormancy states share some physiological and biochemical adjustments. Metabolic depression, regulated Communicated by G. Heldmaier. A. Nicolai (&) Á C. Bertrand Á M. Charrier University of Rennes 1, UMR CNRS 6553 EcoBio, Campus de Beaulieu, 35042 Rennes Cedex, France e-mail: annegret.nicolai@univ-rennes1.fr A. Nicolai Á J. Filser Department of Ecology, University of Bremen, UFT, Leobener Str, 28359 Bremen, Germany R. Lenz University of Economy and Environment Nu ¨rtingen-Geislingen, IAF, Schelmenwasen 4-8, 72622 Nu ¨rtingen, Germany 123 J Comp Physiol B (2011) 181:457–466 DOI 10.1007/s00360-010-0539-x