QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online May 29, 2009
Journal of Experimental Biology 212, 1859-1868 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.027987

This Article Figures Only Full Text Full Text (PDF) Supplementary Material Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Colson-Proch, C. Articles by Hervant, F. PubMed PubMed Citation Articles by Colson-Proch, C. Articles by Hervant, F. Social Bookmarking                         What's this?

Do current environmental conditions explain physiological and metabolic responses of subterranean crustaceans to cold?

Céline Colson-Proch^1,*, David Renault², Antoine Gravot³, Christophe J. Douady^1,4 and Frédéric Hervant¹

¹ Equipe `Hydrobiologie et Ecologie Souterraine', CNRS, UMR5023, `Ecologie des Hydrosystèmes Fluviaux', Université de Lyon, Université Lyon 1, Villeurbanne, F-69622, France
² Equipe `Paysages-Changements climatiques-Biodiversité', CNRS, UMR6553, `Ecosystèmes-Biodiversité-Evolution', Université de Rennes 1, Rennes, F-35042, France
³ INRA, UMR118, `Amélioration des Plantes et Biotechnologies Végétales', Le Rheu, F-35653, France
⁴ Institut Universitaire de France, Paris, F-75005, France

^* Author for correspondence (e-mail: celine.colson{at}ens-lyon.org)

Accepted 26 March 2009

Subterranean environments are characterized by the quasi absence of thermal variations (±1°C within a year), and organisms living in these biotopes for several millions of years, such as hypogean crustaceans, can be expected to have adapted to this very stable habitat. As hypogean organisms experience minimal thermal variation in their native biotopes, they should not be able to develop any particular cold adaptations to cope with thermal fluctuations. Indeed, physiological responses of organisms to an environmental stress are proportional to the amplitude of the stress they endure in their habitats. Surprisingly, previous studies have shown that a population of an aquatic hypogean crustacean, Niphargus rhenorhodanensis, exhibited a high level of cold hardiness. Subterranean environments thus appeared not to be following the classical above-mentioned theory. To confirm this counter-example, we studied seven karstic populations of N. rhenorhodanensis living in aquifers at approximately 10°C all year round and we analysed their behavioural, metabolic and biochemical responses during cold exposure (3°C). These seven populations showed reduced activities, and some cryoprotective molecules were accumulated. More surprisingly, the amplitude of the response varied greatly among the seven populations, despite their exposure to similar thermal conditions. Thus, the overall relationship that can be established between the amplitude of thermal variations and cold-hardiness abilities of ectotherm species may be more complex in subterranean crustaceans than in other arthropods.

Key words: cold hardiness, free amino acid, hypogean crustacean, thermal variation, trehalose

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?