What is the main food source of the shipworm (Teredo navalis)? A stable isotope approach

Stable isotope analysis of soft bodies of the shipworm Teredo navalis demonstrated that this species is mainly feeding on seston by filter feeding in contrast to wood consumption. T. navalis showed similar stable isotope values (δ13C, δ15N) as Mytilus edulis and Crassostrea gigas, which species were attached to the wood instead of boring into. •We compared δ13C and δ15N values of shipworm, Blue mussel, Pacific oyster and wood.•Values of shipworm, mussel, oyster were much higher than those of wood.•Values of the shipworm closely resembled the values of mussel and oyster.•Food obtained by filter feeding is the main source of C and N for the shipworm.•Teredo navalis drills in wood for shelter rather than food.