Growth and behaviour of blue mussels, a re-emerging polar resident, follow a strong annual rhythm shaped by the extreme high Arctic light regime

• Published in: Royal Society Open Science
• Main Authors: Tran, Damien, Andrade, Hector, Durier, Guillaume, Ciret, Pierre, Leopold, Peter, Sow, Mohamedou, Ballantine, Carl, Camus, Lionel, Berge, Jørgen, Perrigault, Mickael
• Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Ecology; conservation; and global change biology Arctic mussel; Mytilus sp; shell growth; annual rhythm; valve behaviour; photoperiod; [SDE]Environmental Sciences; [SDV]Life Sciences [q-bio]; Arctic
• Online Access: https://hal.science/hal-03053501; https://hal.science/hal-03053501/document; https://hal.science/hal-03053501/file/Tran%20et%20al%202020%20rsos.pdf; https://doi.org/10.1098/rsos.200889

International audience Polar regions are currently warming at a rate above the global average. One issue of concern is the consequences on biodiversity in relation to the Northward latitudinal shift in distribution of temperate species. In the present study, lasting almost two years, we examined two phenological traits, i.e. the shell growth and behavioural rhythm of a recently re-established species in the high Arctic, the blue mussel Mytilus sp. We compared this with a native species, the Islandic scallop Chlamys islandica. We show marked differences in the examined traits between the two species. In Mytilus sp., a clear annual pattern of shell growth strongly correlated to the valve behaviour rhythmicity, whereas C. islandica exhibited a shell growth pattern with a total absence of annual rhythmicity of behaviour. The shell growth was highly correlated to the photoperiod for the mussels but weaker for the scallops. The water temperature cycle was a very weak parameter to anticipate the phenology traits of both species. This study shows that the new resident in