title: Response of Two Mytilids to a Heatwave: The Complex Interplay of Physiology, Behaviour and Ecological Interactions.
abstract: Different combinations of behavioural and physiological responses may play a crucial role in the ecological success of species, notably in the context of biological invasions. The invasive mussel Xenostrobus securis has successfully colonised the inner part of the Galician Rias Baixas (NW Spain), where it co-occurs with the commercially-important mussel Mytilus galloprovincialis. This study investigated the effect of a heatwave on the physiological and behavioural responses in monospecific or mixed aggregations of these species. In a mesocosm experiment, mussels were exposed to simulated tidal cycles and similar temperature conditions to those experienced in the field during a heat-wave that occurred in the summer of 2013, when field robo-mussels registered temperatures up to 44.5°C at low tide. The overall responses to stress differed markedly between the two species. In monospecific aggregations M. galloprovincialis was more vulnerable than X. securis to heat exposure during emersion. However, in mixed aggregations, the presence of the invader was associated with lower mortality in M. galloprovincialis. The greater sensitivity of M. galloprovincialis to heat exposure was reflected in a higher mortality level, greater induction of Hsp70 protein and higher rates of respiration and gaping activity, which were accompanied by a lower heart rate (bradycardia). The findings show that the invader enhanced the physiological performance of M. galloprovincialis, highlighting the importance of species interactions in regulating responses to environmental stress. Understanding the complex interactions between ecological factors and physiological and behavioural responses of closely-related species is essential for predicting the impacts of invasions in the context of future climate change.
authors.affiliation: Departamento de Ecoloxía y Bioloxía Animal, Universidade de Vigo, 36310, Vigo, Spain.
authors.forename: Celia
authors.initials: C
authors.lastname: Olabarria
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Quinta do Lorde Marina, Sítio da Piedade, 9200-044, Caniçal, Madeira, Portugal.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Gestoso
authors.affiliation: CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661, Vairão, Portugal.
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Lima
authors.affiliation: Departamento de Ecoloxía y Bioloxía Animal, Universidade de Vigo, 36310, Vigo, Spain.
authors.forename: Elsa
authors.initials: E
authors.lastname: Vázquez
authors.affiliation: Department of Fisheries and Oceans, Science Branch, Gulf Fisheries Centre, P.O. Box 5030, Moncton, NB, E1C 9B6, Canada.
authors.forename: Luc A
authors.initials: LA
authors.lastname: Comeau
authors.affiliation: CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661, Vairão, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Gomes
authors.affiliation: CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661, Vairão, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Seabra
authors.affiliation: Department of Biotechnology and Aquaculture, Instituto de Investigaciones Marinas CSIC, Eduardo Cabello 6, 36208, Vigo, Spain.
authors.forename: José M F
authors.initials: JM
authors.lastname: Babarro
mesh_terms: D000818:Animals; D057231:Climate Change; D007259:Infrared Rays; D058865:Introduced Species; D049879:Mytilidae / Q000145:classification / Q000502:physiology*; D013045:Species Specificity; D013312:Stress, Physiological