REVIEWS Arctica islandica: the longest lived non colonial animal known to science I. D. Ridgway • C. A. Richardson Received: 5 February 2010 / Accepted: 31 July 2010 / Published online: 11 August 2010 Ó Springer Science+Business Media B.V. 2010 Abstract The ocean quahog, Arctica islandica is not just the longest living bivalve, it is also the longest lived, non-colonial animal known to science. With the maximum life span potential ever increasing and currently standing in excess of 400 years the clam has recently gained interest as a potential model organism for ageing research. This review details what is known about the biology of A. islandica, it discusses observed age-associated changes and reviews previous ageing research undertaken on the species and other long-lived bivalves which may be applicable to future ageing research and discusses future directions for ageing research with A. islan- dica. Historically much of the research on bivalves has been targeted at their utilization as a food source, environmental sentinels and more recently the use of their shells as archives of environmental change. The result of this has been an abundance of knowledge on bivalve life strategies, and a limited amount of information on the physiological changes in the cells and tissues of bivalves during the ageing process. However, research into the mechanisms of senes- cence of long-lived bivalves from a biogerontological perspective has advanced only recently. The research undertaken thus far has documented age-related differences in anti-oxidant defences and accumula- tion of oxidative products but despite the recent attention into ageing of A. islandica it is still to be ascertained if the species experiences senescence. Future directions for ageing research using A. islan- dica are discussed. Keywords Bivalves Á Model organism Á Negligible senescence Á Arctica islandica Introduction The Ocean Quahog Arctica islandica, also known as the Iceland Cyprina and Mahogany Clam is not just the longest living bivalve, it is also the longest lived, non-colonial animal known to science (Wana- maker et al. 2008). With the estimates of the maximum life span potential (MLSP) for this clam ever increasing (Thompson et al. 1980a; Jones 1983; Ropes 1985; Scho ¨ne et al. 2005; Scourse et al. 2006), currently standing between 405 and 410 years (Wanamaker et al. 2008), A. islandica has recently gained interest as a potential model organism for ageing research. Significant advances in the under- standing of ageing processes have been made using classical model organisms of ageing research such as yeasts, fruit flies, nematodes and rodents. Despite the advantages of these organisms, where their basic I. D. Ridgway (&) Á C. A. Richardson School of Ocean Sciences, College of Natural Sciences, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK e-mail: iain.ridgway@bangor.ac.uk 123 Rev Fish Biol Fisheries (2011) 21:297–310 DOI 10.1007/s11160-010-9171-9