1. Measuring cortisol in fish scales to study stress in wild tropical tuna
- Author
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Emmanuelle Roque D'Orbcastel, Benjamin Geffroy, Thierry Bouvier, Yvan Bettarel, Justin Monin Amande, Laurent Dagorn, Marion Dellinger, Bastien Sadoul, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), Department of Aquaculture and Fish Biology, Holar University College, Écologie et santé des écosystèmes (ESE), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre de Recherches Océanologiques [Abidjan] (CRO), AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
- Subjects
0106 biological sciences ,Skipjack tuna ,Yellowfin tuna ,[SDE.MCG]Environmental Sciences/Global Changes ,Zoology ,Welfare ,Aquatic Science ,010603 evolutionary biology ,01 natural sciences ,Cortisol ,Fish scales ,14. Life underwater ,Ecology, Evolution, Behavior and Systematics ,Skipjack ,Kipjack tuna ,biology ,010604 marine biology & hydrobiology ,biology.organism_classification ,Indian ocean ,Elisa test ,[SDE]Environmental Sciences ,%22">Fish ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Tuna ,Tress ,Thunnus - Abstract
WOS:000667043200001; International audience; Cortisol is recognized as a physiological indicator of stress in fish. However, this hormone is typically measured in plasma samples. In this study, cortisol content was evaluated for the first time in the scales of tropical tuna. The sample included 20 skipjack tuna (Katsuwonus pelamis) and 25 yellowfin tuna (Thunnus albacares) collected in the Atlantic (the Gulf of Guinea off the Ivory Coast) and the Indian Ocean (off Reunion Island), and their scales were analyzed using an ELISA test. The results indicated that on average, cortisol concentration (1) did not show any geographical pattern, (2) was independent of fish size, and (3) was significantly higher in skipjack (mean 4.75 ± 6.56 ng g−1) than in yellowfin (mean 1.65 ± 1.85 ng g−1), although the difference was mainly due to four skipjack individuals. Larger datasets would be needed to confirm any species difference in cortisol concentration. The particularly high cortisol concentration observed in four individuals may be due to fish from different schools, suggesting the need for future sampling from free-swimming schools to investigate intra- and inter-school variability in cortisol concentration. This study opens the door for future research, including the collection of scales on tagged individuals, to investigate the links between chronic stress and behavior in these species.
- Published
- 2021