Ecophysiology of native and alien-invasive clams in an ocean warming context.
Both climate change and biological invasions are among the most serious global environmental threats. Yet mechanisms underlying these eventual interactions remain unclear. The aim of this study was to undertake a comprehensive examination of the physiological and biochemical responses of native (Ruditapes decussatus) and alien-invasive (Ruditapes philippinarum) clams to environmental warming. We evaluated thermal tolerance limits (CTMax), routine metabolic rates (RMRs) and respective thermal sensitivity (Q10 values), critical oxygen partial pressure (Pcrit), heat shock response (HSP70/HSC70 levels), lipid peroxidation (MDA build-up) and antioxidant enzyme [glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD)] activities. Contrary to most studies that show that invasive species have a higher thermal tolerance than native congeners, here we revealed that the alien-invasive and native species had similar CTMax values. However, warming had a stronger effect on metabolism and oxidative status of the native R. decussatus, as indicated by the higher RMRs and HSP70/HSC70 and MDA levels, as well as GST, CAT and SOD activities. Moreover, we argue that the alien-invasive clams, instead of up-regulating energetically expensive cellular responses, have evolved a less demanding strategy to cope with short-term environmental (oxidative) stress-pervasive valve closure. Although efficient during stressful short-term periods to ensure isolation and guarantee longer survival, such adaptive behavioural strategy entails metabolic arrest (and the enhancement of anaerobic pathways), which to some extent will not be advantageous under the chronically warming conditions predicted in the future.
Laboratório Marítimo da Guia, Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, Cascais 2750-374, Portugal; Divisão de Aquacultura e Valorização (DivAV), Instituto Português do Mar e da Atmosfera (IPMA, I.P.), Av. Brasília, Lisboa 1449-006, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, Porto 4050-123, Portugal. Electronic address: panacleto@ipma.pt.
Patrícia
P
Anacleto
Divisão de Aquacultura e Valorização (DivAV), Instituto Português do Mar e da Atmosfera (IPMA, I.P.), Av. Brasília, Lisboa 1449-006, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, Porto 4050-123, Portugal.
Ana Luísa
AL
Maulvault
Laboratório Marítimo da Guia, Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, Cascais 2750-374, Portugal.
Vanessa M
VM
Lopes
Laboratório Marítimo da Guia, Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, Cascais 2750-374, Portugal.
Tiago
T
Repolho
REQUIMTE, Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal.
Mário
M
Diniz
Divisão de Aquacultura e Valorização (DivAV), Instituto Português do Mar e da Atmosfera (IPMA, I.P.), Av. Brasília, Lisboa 1449-006, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, Porto 4050-123, Portugal.
Maria Leonor
ML
Nunes
Divisão de Aquacultura e Valorização (DivAV), Instituto Português do Mar e da Atmosfera (IPMA, I.P.), Av. Brasília, Lisboa 1449-006, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, Porto 4050-123, Portugal.
António
A
Marques
Laboratório Marítimo da Guia, Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, Cascais 2750-374, Portugal.
Rui
R
Rosa
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D049872:Bivalvia / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002374:Catalase / Q000378:metabolism; D057231:Climate Change; D004784:Environmental Monitoring; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D018869:Heat-Shock Response; D015227:Lipid Peroxidation / Q000235:genetics; D009792:Oceans and Seas; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D018840:HSP70 Heat-Shock Proteins; D002374:Catalase; D013482:Superoxide Dismutase
Biological invasions; Metabolism; Oxidative stress; Ruditapes decussatus; Ruditapes philippinarum; Thermal tolerance