Scientists meeting this week in Scotland said thousands of interesting new compounds have been discovered in the bodies of marine sponges.

The researchers attending the Society for General Microbiology's 161st meeting said more than half of the bodyweight of living sea sponges consists of different bacteria that live inside them.

"Marine sponges are the most prolific and important source of new active compounds discovered in the last 20 or 30 years in our seas," said Detmer Sipkema of the University of California-Berkeley. "We thought it likely that many of the interesting new compounds we were discovering inside sea sponges were actually being made by the bacteria inside their bodies, not the sponges themselves."