Bivalves include species with the longest metazoan lifespan approaching 400 years . Ocean quahog Artctica islandica is the longest-lived of all bivalve and molluscan species on our planet. A lifespan close to 400 is common for this species . A. islandica can live more than 500 years [http://www.museumwales.ac.uk/en/whatson/?event_id=5464].
In A. islandica, after maturation catalase citrate synthase activity and glutathione concentration are kept rather stable for > 150 years. Remarkable, superoxide dismutase activities are maintained on high levels throughout life time .
Extreme longevity appears to be associated with an attenuated cellular reactive oxygen species production. Tissues of A. islandica have compared to short-lived M mercenaria reduced protein carbonyl concentration indicating that reduced reactive oxygen species production in long-living bivalves is associated with lower levels of accumulated marcomolecular damage. Thus, suggesting that cellular redox homeostasis may determine lifespan. A. islandica displays neither greater antioxidant capacities nor specific activities than in short-lived M. merenaria nor a more pronounced homeostatic antioxidant response following oxidative stress. A. islandica also does not appear to have enhanced protein recycling . o