The circum-Antarctic clam Laternula elliptica (King & Broderip 1831) is the largest infaunal bivalve of the Southern Ocean. It mostly lives in water depths of less than 100 m (highest densities from 20–30 m; e.g. Ahn 1994), in soft or semi-consolidated substrates from sandy mud to gravelly sand (Soot-Ryen 1951, Nicol 1966). Animals are deep-burrowing (to >0.5 m; Zamorano et al. 1986) and consequently have large siphons. These are fused, highly muscular and covered by thick, rugose periostracum, and are capable of partial retraction only (Burne 1920). The ecology of L. elliptica was likened by Ralph & Maxwell (1977) to that of Mya arenaria L. in northern temperate and Arctic waters.