title: Haemolymph [Na+] and [Cl-] loss in Gammarus fossarum exposed in situ to a wide range of acidic streams.
abstract: The acid-sensitive amphipod Gammarus fossarum was exposed in situ for 24, 96 and 168 h to 18 streams (9 draining from granite and 9 draining from sandstone bedrock), selected in order to provide a wide range of acidification. After 24 h, exposure to slightly acidic (6.00 < or = pH < or = 5.50) and strongly acidic water (pH < 5.50) led to a severe and significant depletion in haemolymph [Na+] and [Cl-] compared to organisms exposed in circumneutral water. Highly significant linear correlations between stream mean pH value and haemolymph [Na+] and [Cl-] were observed for each exposure time on each bedrock. Organisms exposed to slightly acid streams draining granite bedrock (pH = 5.71, pH = 5.81) showed a physiological adaptation after 96 h of exposure, while animals in acidic sandstone streams did not. Results of this study indicate that haemolymph [Na+] and [Cl-] in G. fossarum could be an effective ecophysiological marker for monitoring freshwater ecosystem acidification.
authors.affiliation: Laboratoire Biodiversité et Fonctionnement des Ecosystèmes, Université de Metz, UFR Sci-FA, Rue du Général Delestraint, 57070 Metz, France. v_felten@club-internet.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: Felten
authors.forename: François
authors.initials: F
authors.lastname: Guerold
mesh_terms: D033304:Amphipoda / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D002712:Chlorides / Q000097:blood*; D005602:France; D055593:Geological Phenomena; D005844:Geology; D006458:Hemolymph / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D045483:Rivers / Q000737:chemistry*; D012964:Sodium / Q000097:blood*; D013997:Time Factors
chemical_list: D002712:Chlorides; D012964:Sodium