MEPS 216:141-149 (2001)  -  doi:10.3354/meps216141

Temperature resistance of Hesiolyra bergi, a polychaetous annelid living on deep-sea vent smoker walls

Bruce Shillito1,*, Didier Jollivet2, Pierre-Marie Sarradin3, Philippe Rodier3, François Lallier2, Daniel Desbruyères3, Françoise Gaill1

1Unité Mixte de Recherche 7622 (UMR), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie Moleculaire et Cellulaire du Developpement (LBMCD), Marine Biology Group, University of Paris (UPMC), 7 Quai St Bernard, Batiment A, 75252 Paris Cedex 5, France
2Roscoff Marine Station, Unité Propre de Recherche (UPR) 9042, Centre National de la Recherche Scientifique (CNRS), Ecophysiology Group, BP 74, 29682 Roscoff Cedex, France
3Institut Français de Recherche Pour l¹Exploitation de la Mer (IFREMER) Centre de Brest, DRO-EP, BP 70, 29280 Plouzané, France

ABSTRACT: For the first time, in vivo heat-exposure experiments were conducted on the hydrothermal vent polychaete Hesiolyra bergi from the hottest part of the vent biotope. Using a pressurised incubator equipped with video-facilities, we found that H. bergi, which forages around and in the tubes of the thermophilic Alvinella sp., became hyperactive once temperature exceeded 35°C and further lost co-ordination in the 41 to 46°C interval, just before death occurred. Another exposure experiment at 39°C for 3 to 4 h led to 80% mortality (max) 9 h after heat shock, and 100% thereafter. In view of the much higher temperatures recorded in this organism¹s habitat, these results suggest that tolerance to high temperatures (exceeding 40°C) is not a pre-requisite for life amongst alvinellid tubes. Behavioural responses (escape from heat) may suffice.

KEY WORDS: Hydrothermal vents · Behaviour · Adaptation to heat · IPOCAMP

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