Related Clues:

• The sort of seafood that the seaman got all by himself
• Might the graduate turn up and come out of his shell all by himself?
• AB retired into his shell for solitary
• A graduate by himself does not come out of his shell
• Source of iridescent buttons
• Unaccompanied sailor has seafood
• Sailor gets sole - a type of seafood
• Seafood for the sailor aboard the Mary Celeste?
• Sailor's forlorn seafood
• Gastropod consisting of muscle only
• Seafood for sailor on his tod
• Mollusc
• Large, snail-like mollusc
• Shell lined with mother-of-pearl
• It's called 'awabi' at a sushi bar