title: Native and introduced clams biochemical responses to salinity and pH changes.
abstract: By the end of year 2100 physiological and biochemical performance of aquatic organisms are expected to become strongly affected by salinity and pH shifts, which in turn may favor the conditions for introduced species to invade new ecosystem areas. Given this, we evaluated the effects of salinity and pH changes in native Ruditapes decussatus and introduced Ruditapes philippinarum clams, by measuring different biomarkers related to oxidative stress, metabolic activity and osmoregulation capacity. Results showed that extreme salinities induced mortality in both species, while all clams survived under low pH (7.3). Both species mobilized glycogen as a source of energy towards cells protection mechanisms under extreme salinities. The native species presented higher lipid peroxidation levels while the introduced species was able to prevent oxidative damages through the induction of antioxidant enzymes at most extreme salinities. R. philippinarum also induced CA activity to balance the ion homeostasis at extreme salinities. In contrast, low pH induced oxidative damages, an increase of antioxidant (catalase), detoxification (glutathione S-transferases) and osmoregulation (carbonic anhydrase) mechanisms in R. philippinarum compared to the native clams. Overall, salinity and pH changes can alter physiological and biochemical status of native and introduced clam species.
authors.affiliation: Departamento de Biologia & CESAM, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Catia
authors.initials: C
authors.lastname: Velez
authors.affiliation: Departamento de Biologia & CESAM, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Etelvina
authors.initials: E
authors.lastname: Figueira
authors.affiliation: Departamento de Biologia & CESAM, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Amadeu M V M
authors.initials: AMVM
authors.lastname: Soares
authors.affiliation: Departamento de Biologia & CESAM, Universidade de Aveiro, 3810-193 Aveiro, Portugal. Electronic address: rosafreitas@ua.pt.
authors.forename: Rosa
authors.initials: R
authors.lastname: Freitas
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D049872:Bivalvia / Q000201:enzymology / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D058865:Introduced Species; D064587:Osmoregulation; D018384:Oxidative Stress; D011174:Portugal; D054712:Salinity; D012623:Seawater / Q000737:chemistry*
chemical_list: D015415:Biomarkers
keywords: Oxidative stress; R. philippinarum; Ruditapes decussatus; Salinity; Seawater acidification