title: Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean.
abstract: Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm) significantly decreased metabolic rates (up to 27.4 %) of flatfish larvae, Solea senegalensis, at both present (18 °C) and warmer temperatures (+4 °C). Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT) and glutathione S-transferase (GST), mainly in post-metamorphic larvae (30 dph). The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph) seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase) and intestinal enzymes (up to 36.1 % for alkaline phosphatase) in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels) were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems.
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374, Cascais, Portugal; Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto, Largo Prof. Abel Salazar 2, 4099-003, Porto, Portugal.
authors.forename: Marta S
authors.initials: MS
authors.lastname: Pimentel
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374, Cascais, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Faleiro
authors.affiliation: REQUIMTE, Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516, Caparica, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Diniz
authors.affiliation: Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto, Largo Prof. Abel Salazar 2, 4099-003, Porto, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Machado
authors.affiliation: Instituto Português do Mar e da Atmosfera, Av. 5 de Outubro, 8700-305, Olhão, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Pousão-Ferreira
authors.affiliation: Institute for Hydrobiology and Fisheries Science, University of Hamburg, Olbersweg 24, 22767, Hamburg, Germany.
authors.forename: Myron A
authors.initials: MA
authors.lastname: Peck
authors.affiliation: Alfred Wegener Institute for Polar and Marine Research, Animal Ecophysiology, Postfach 120161, 27515, Bremerhaven, Germany.
authors.forename: Hans O
authors.initials: HO
authors.lastname: Pörtner
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374, Cascais, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Rosa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D004063:Digestion; D005412:Flatfishes / Q000378:metabolism* / Q000502:physiology; D057232:Global Warming; D018869:Heat-Shock Response; D007814:Larva / Q000201:enzymology / Q000378:metabolism; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D010101:Oxygen Consumption; D012623:Seawater
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde