The shipworm, despite its name, is not a worm at all. Instead it is a type of marine clam that burrows into the wood of ships and piers where it wreaks havoc. The shipworm feeds on the wood, thus weakening the ships and piers it inhabits. But wood is a nutrient-poor food source which by itself does not provide the protein necessary to sustain the clam. To live, it relies on bacteria that live within its gills. These bacteria form a symbiotic partnership with the shipworm and enable the tiny clam to harvest nitrogen from the air and convert that nitrogen into much needed protein.

The protein-production methods employed by the shipworm represent a novel way for animals to feed. The closest comparison could be to the feeding methods of wood-eating termites. Like the shipworks, wood-eating termites supplement their diet of wood with nitrogen. But the termintes obtain their nitrogen from a collection of nitrogen-fixing bacteria that reside within the insect's gut.

The discovery of the shipworm's unique feeding abilities offers insights into other areas of research. By understanding the shipworm's method of converting wood and air into food and energy, scientists can gain insights into ways we might produce energy from renewable sources such as cellulose.

The study of the shipworm was performed by scientists from the Ocean Genome Legacy and Harvard Medical School under a grant from the National Science Foundation.

Find out more:

• Clams Convert Air into Food (NSF)
• Research at Ocean Genome Legacy (OGL)