The Dodecanese island of Kalymnos is famous for its daring sponge divers. When they also nab sea squirts (foukes), too, and remove the flesh from the shell and pop them into a bottle of sea water, often with sea urchins (achinous) or any other mollusc they find. As the divers were often away for long periods at sea, it was a way of preserving seafood for hungry times.
Today you can find bottles of spinialo in the island's shops, or served as a mezede in a bar or taverna.
Image by kalymnosdelicatessen