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Auteur (up) Blasco, F.R.; Esbaugh, A.J.; Killen, S.S.; Rantin, F.T.; Taylor, E.W.; McKenzie, D.J. doi  openurl
  Titre Using aerobic exercise to evaluate sub-lethal tolerance of acute warming in fishes Type Article scientifique
  Année 2020 Publication Revue Abrégée J. Exp. Biol.  
  Volume 223 Numéro 9 Pages jeb218602  
  Mots-Clés capacity; climate-change; CTmax; hypoxia tolerance; marine fishes; Oreochromis niloticus; oxygen-tensions; performance; Piaractus mesopotamicus; scope; sea bass; temperature; thermal tolerance  
  Résumé We investigated whether fatigue from sustained aerobic swimming provides a sub-lethal endpoint to define tolerance of acute warming in fishes, as an alternative to loss of equilibrium (LOE) during a critical thermal maximum (CTmax) protocol. Two species were studied, Nile tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus). Each fish underwent an incremental swim test to determine gait transition speed (U-GT), where it first engaged the unsteady anaerobic swimming mode that preceded fatigue. After suitable recovery, each fish was exercised at 85% of their own U-GT and warmed 1 degrees C every 30 min, to identify the temperature at which they fatigued, denoted as CTswim. Fish were also submitted to a standard CTmax, warming at the same rate as CTswim, under static conditions until LOE. All individuals fatigued in CTswim, at a mean temperature approximately 2 degrees C lower than their CTmax. Therefore, if exposed to acute warming in the wild, the ability to perform aerobic metabolic work would be constrained at temperatures significantly below those that directly threatened survival. The collapse in performance at CTswim was preceded by a gait transition qualitatively indistinguishable from that during the incremental swim test. This suggests that fatigue in CTswim was linked to an inability to meet the tissue oxygen demands of exercise plus warming. This is consistent with the oxygen and capacity limited thermal tolerance (OCLTT) hypothesis, regarding the mechanism underlying tolerance of warming in fishes. Overall, fatigue at CTswim provides an ecologically relevant sub-lethal threshold that is more sensitive to extreme events than LOE at CTmax.  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0022-0949 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000541842300012 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2817  
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