Abstract The ocean quahog Arctica islandica is the longest–living mollusk on Earth with a lifespan of at least 500 years. The slow senescence of this bivalve has promoted a great interest in its metabolic strategy. A dynamic energy budget (DEB) model was applied to describe how this species allocates its energy to maintenance, growth, maturation, and reproduction in a variable environment. We studied the relationship between A. islandica growth, lifespan, and food availability at eight different locations in the North Atlantic Ocean. Our results indicate that A. islandica's extreme longevity arises from its low somatic maintenance cost p ̇ M and low ageing acceleration h ¨ a , but there was not a direct relationship between food availability and lifespan in these A. islandica locations. Monkey Bank (North Sea), Iceland, and Ingøya (northern Norway) had the highest food availability estimates of all the localities but did not have the lowest longevities, in contrast to the theory of caloric restriction. Highlights • Arctica islandica extreme longevity arises from its low metabolism. • DEB food parameter can be used as an indicator of A. islandica food availability. • Lifespan was not directly related to food availability for A. islandica populations. [ABSTRACT FROM AUTHOR]