Heart beat rate: a physiological response to thermal stress in blue mussels species.
- Autori: Zenone, A; De Pirro, M; Sarà, G; Helmuth, B
- Anno di pubblicazione: 2009
- Tipologia: Proceedings (TIPOLOGIA NON ATTIVA)
- Parole Chiave: intertidal, heart beat rate, bivalve, climate change
- OA Link: http://hdl.handle.net/10447/44043
Non-native species often have ecological impacts on invaded communities. The quanti#cation of features of invaders and recipient ecosystems facilitating and/or interfering with successful invasion remains a challenge because of several factors may in!uence the success of invasions. Among them, life history strategies (e.g., reproductive potential, body size), ability to avoid predators, disease resistance and physiological compensatory mechanisms to adapt to changing habitats are among the most important factors. The latter has been often invoked as the key to success for many intertidal invasive invertebrates and have been suggested as key indicators of invasibility rate and the ultimate distribution on worldwide coastal intertidal habitats. The physiological ability to adapt to cycling thermal stress conditions is one important aspect of these species to thrive of intertidal habitats. The present study reports on the physiological e"ect of thermal stress both at low tide and high tide of Mytilus galloprovincialis, a Mediterranean species which is an invader in Northern American intertidal habitats and M. trossulus, a sibling species. Heart beat rate (HBR) of the species was measured in high tide standard condition (12°C, 28 ‰ of salinity) and at 4 di"erent body temperatures (20°, 25°, 30°, 35°C) during low tide condition (aerial exposure). HBR of M. trossulus, during high tide condition was signi#cantly higher (23.66 ± 2.52 beat*min-1, p<0.001) than that of M. galloprovincialis (19.62 ± 0.26 beat*min-1); this is consistent with the evolutionary adaptation to a lower habitat temperature (temperature compensation) in the former species. During low tide conditions at di"erent body temperatures, mussels of the two species showed similar behaviour. Both species increase quickly their HBR after emersion, showing a tachycardia typical of initial emersion condition than HBR fell sharply to bradycardia up to the time which mussels are re-immersed in water.