title: Respiratory response to combined heat and hypoxia in the marine bivalves Pecten maximus and Mytilus spp.
abstract: Coastal ecosystems are increasingly disturbed by the increase of mean sea surface temperature and expansion of hypoxic areas. The objectives of the present work were to describe and compare the respiratory responses to combined heat and hypoxia in two bivalve species (Pecten maximus and Mytilus spp.) living in two contrasted coastal habitats (subtidal and intertidal, respectively). Results were consistent with the vertical zonation of both species. Mytilus spp. seemed to cope better with a temperature increase than P. maximus, which was found to be outside of its optimal thermal window at 25°C. Concerning respiratory responses to hypoxia at a given temperature, P. maximus displayed greater oxyregulation capacity that was maintained over a larger range of O2 levels, as compared to Mytilus spp. When acclimation temperatures increased, both species showed a decrease in their oxyregulation capacities alongside a reduction in aerobic performance, especially in P. maximus. The comparison between species suggests that subtidal species, such as P. maximus, might be more vulnerable to a combination of heat and hypoxia than intertidal species, such as Mytilus spp. Lastly, this study highlighted the utility of segmented linear models to estimate PcO2 and regulation percentages in marine organisms exposed to hypoxia.
authors: Laboratoire des Sciences de l'Environnement Marin, LEMAR UMR 6539 CNRS/UBO/IRD/Ifremer, Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer, 29280 Plouzané, France. Electronic address: sebastien.artigaud@univ-brest.fr.
authors: Sébastien
authors: S
authors: Artigaud
authors: Laboratoire des Sciences de l'Environnement Marin, LEMAR UMR 6539 CNRS/UBO/IRD/Ifremer, Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer, 29280 Plouzané, France.
authors: Camille
authors: C
authors: Lacroix
authors: Laboratoire des Sciences de l'Environnement Marin, LEMAR UMR 6539 CNRS/UBO/IRD/Ifremer, Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer, 29280 Plouzané, France.
authors: Vianney
authors: V
authors: Pichereau
authors: Laboratoire des Sciences de l'Environnement Marin, LEMAR UMR 6539 CNRS/UBO/IRD/Ifremer, Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer, 29280 Plouzané, France.
authors: Jonathan
authors: J
authors: Flye-Sainte-Marie
mesh_terms: D000064:Acclimatization / Q000502:physiology; D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology; D017753:Ecosystem; D006358:Hot Temperature; D000860:Hypoxia / Q000378:metabolism*; D049878:Mytilus / Q000502:physiology; D009792:Oceans and Seas; D049910:Pecten / Q000502:physiology; D012143:Respiratory Physiological Phenomena; D013696:Temperature
keywords: Bivalves; Hypoxia; Marine biology; Oxyregulation; Respiration; Temperature