The Teredo Worm is found in rotting wood and logs of mangroves. Looks like a long thin worm but is actually a mollusc. Can be found at low tide and tastes like an oyster. Generally eaten as a tonic for general sickness.
This photo of the worms was taken in South East Asia where they also flourish. It gives you can idea of what they look like. They are considered a delicacy!