Deep Sea Buffet For Bone-Devouring Worms

An unusual relationship between bacteria and a newly discovered group of marine worms is the only known partnership (or symbiosis) which uses sunken marine mammals as its sole source of nutrition.

In the September issue of Environmental Microbiology, Dr Shana Goffredi and her colleagues reveal this unique partnership between bacteria and the Osedax (bone-devouring) group of marine worms.

Symbiosis, or the living together of different organisms, allows some species to live in otherwise hostile environments, so it can be a powerful mechanism of evolutionary change. This is especially true in the deep sea. Survival in some deep-sea environments requires capabilities that animals alone don’t possess. So teaming up with a microbial partner is the secret of survival for many host animals living in such environments.

Dr Goffredi says: “Measures of significant population sizes, and the discovery of four additional host species in only three years, suggests that the Osedax worms and their bacterial ‘partners’ are likely to play substantial roles in the cycling of nutrients into the surrounding deep-sea community.”

This can be put into context by considering that the Osedax worms and their symbiotic bacteria can turn-over a large amount of organic carbon (one whale carcass may weigh up to 50 tons), approximately 2000 years faster than the usual mechanism of carbon deposition to the deep seafloor.

The results of this study will aid understanding of the potential for adaptation between animals and microbes.