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Auteur (up) Rivera-Ingraham, G.A.; Barri, K.; Boel, M.; Farcy, E.; Charles, A.-L.; Geny, B.; Lignot, J.-H. doi  openurl
  Titre Osmoregulation and salinity-induced oxidative stress: is oxidative adaptation determined by gill function? Type Article scientifique
  Année 2016 Publication Revue Abrégée J. Exp. Biol.  
  Volume 219 Numéro 1 Pages 80-89  
  Mots-Clés Antioxidant defense; antioxidant enzymes; blue-crab; callinectes-sapidus; Carcinus aestuarii; crab carcinus-maenas; green crab; na+/k+-atpase activity; Osmoregulation; progressive hypoxia; reactive oxygen; ROS production; shore crab; temporal distribution  
  Résumé Osmoregulating decapods such as the Mediterranean green crab Carcinus aestuarii possess two groups of spatially segregated gills: anterior gills serve mainly respiratory purposes, while posterior gills contain osmoregulatory structures. The co-existence of similar tissues serving different functions allows the study of differential adaptation, in terms of free radical metabolism, upon salinity change. Crabs were immersed for 2 weeks in seawater (SW, 37 ppt), diluted SW (dSW, 10 ppt) and concentrated SW (cSW, 45 ppt). Exposure to dSW was the most challenging condition, elevating respiration rates of whole animals and free radical formation in hemolymph (assessed fluorometrically using C-H(2)DFFDA). Further analyses considered anterior and posterior gills separately, and the results showed that posterior gills are the main tissues fueling osmoregulatory-related processes because their respiration rates in dSW were 3.2-fold higher than those of anterior gills, and this was accompanied by an increase in mitochondrial density (citrate synthase activity) and increased levels of reactive oxygen species (ROS) formation (1.4-fold greater, measured through electron paramagnetic resonance). Paradoxically, these posterior gills showed undisturbed caspase 3/7 activity, used here as a marker for apoptosis. This may only be due to the high antioxidant protection that posterior gills benefit from [superoxide dismutase (SOD) in posterior gills was over 6 times higher than in anterior gills]. In conclusion, osmoregulating posterior gills are better adapted to dSW exposure than respiratory anterior gills because they are capable of controlling the deleterious effects of the ROS production resulting from this salinity-induced stress.  
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  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 Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 1541  
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Auteur (up) Theuerkauff, D.; Rivera-Ingraham, G.A.; Roques, J.A.C.; Azzopardi, L.; Bertini, M.; Lejeune, M.; Farcy, E.; Lignot, J.-H.; Sucre, E. doi  openurl
  Titre Salinity Variation in a Mangrove Ecosystem: A Physiological Investigation to Assess Potential Consequences of Salinity Disturbances on Mangrove Crabs Type Article scientifique
  Année 2018 Publication Revue Abrégée Zool. Stud.  
  Volume 57 Numéro Pages 36  
  Mots-Clés Bioenergetics; blue-crab; callinectes-sapidus; carcinus-maenas; Decapods; dilocarcinus-pagei brachyura; eriocheir-sinensis; fiddler-crabs; fresh-water; grapsid crabs; Mangrove; Osmoregulation; oxidative stress; Salinity-induced oxidative stress; waste-water treatment  
  Résumé Dimitri Theuerkauff, Georgina A. Rivera-Ingraham, Jonathan A.C. Roques, Laurence Azzopardi, Marine Bertini, Mathilde Lejeune, Emilie Farcy, Jehan-Herve Lignot, and Elliott Sucre (2018) Salinity is one of the main environmental factors determining coastal species distribution. However, in the specific case of mangrove crabs, salinity selection cannot be understood through ecological approaches alone. Yet understanding this issue is crucial in the context of mangrove conservation, since this ecosystem is often used as biofilter of (low-salinity) wastewater. Crabs are keystone species in this mangrove ecosystem and are differentially affected by salinity. We hypothesize that crab salinity selection may be partly explained by specific salinity-induced physiological constraints associated with osmoregulation, energy and redox homeostasis. To test this, the response to salinity variation was analysed in two landward mangrove crabs: the fiddler crab Tubuca urvillei, which inhabits low-salinity areas of the mangrove, and the red mangrove crab Neosarmatium meinerti, which lives in areas with higher salinity. Results confirm that both species are strong hypo-/hyper-osmoregulators that deal easily with large salinity variations. Such shifts in salinity do not induce changes in energy expenditure (measured as oxygen consumption) or in the production of reactive oxygen species. However, T. urvillei is physiologically suited to habitats with brackish water, since it presents i) high hemolymph osmolalities over a wider range of salinities and lower osmoregulatory capacity in seawater, ii) high Na+/K+-ATPase (NKA) activity in the posterior osmoregulatory gills and iii) a thicker osmoregulatory epithelium along the posterior gill lamellae. Therefore, while environmental salinity alone cannot directly explain fiddler and red mangrove crab distributions, our data suggest that salinity selection is indeed influenced by specific physiological adjustments.  
  Adresse  
  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 1021-5506 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2424  
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