Possible Clues:

• A shipworm
• Marine mollusc that damages ships
• Shipworm
• Will the bits of the tree do for the worm?
• Marine mollusc that damages wooden ships
• In the broken toe there's a ruddy worm
• Would the bits of the tree do for a worm in the water?
• Would bits of the tree do for this sort of worm?
• Has the ruddy worm got into a broken toe?
• Marine bivalve mollusc of the genus of the same name