Deep-sea hospitality: an enigmatic worm and its symbionts

Shana K. Goffredi (Occidental College, USA) Forty years ago, scientists discovered an animal at the bottom of the ocean that changed forever how we view life on this planet. Abundant, thriving animals were not expected in the deep sea, due to the very low levels of organic carbon that sink down from above. The giant tubeworm Riftia pachyptila pays little attention to this problem, having renounced its mouth and digestive system during the course of evolution. Instead, this animal relies on a partnership with internal bacteria that act as a built-in source of nourishment and, in exchange, Riftia performs unparalleled physiological feats.