Non-native species often have ecological impacts on invaded communities. Thequanti#cation of features of invaders and recipient ecosystems facilitating and/orinterfering with successful invasion remains a challenge because of several factors mayin!uence the success of invasions. Among them, life history strategies (e.g., reproductivepotential, body size), ability to avoid predators, disease resistance and physiologicalcompensatory mechanisms to adapt to changing habitats are among the most importantfactors. The latter has been often invoked as the key to success for many intertidalinvasive invertebrates and have been suggested as key indicators of invasibility rateand the ultimate distribution on worldwide coastal intertidal habitats. The physiologicalability to adapt to cycling thermal stress conditions is one important aspect of thesespecies to thrive of intertidal habitats. The present study reports on the physiologicale"ect of thermal stress both at low tide and high tide of Mytilus galloprovincialis, aMediterranean species which is an invader in Northern American intertidal habitats andM. trossulus, a sibling species. Heart beat rate (HBR) of the species was measured in hightide 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 theevolutionary 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 quicklytheir HBR after emersion, showing a tachycardia typical of initial emersion conditionthan HBR fell sharply to bradycardia up to the time which mussels are re-immersed inwater.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2009|