The limpet "Latia neritoides" is the only known freshwater gastropod that emits light. They are named because of the similarity to the limpet, a mollusk. Wales is known for its shellfish, including cockles, limpet, mussels and periwinkles. The LTTE developed several types of improvised naval mines including moored, floating and limpet mines. They specialised in using canoes for limpet mine attacks in Arctic waters. They would then use folding kayaks to attach limpet mines to Japanese ships. The Una-class boats carried five crewmen, eight combat swimmers, four Mala vehicles, and limpet mines. They again allegedly showed IRGC members removing an unexploded limpet mine. Limpet tooth structure is dependent upon living depth of the specimen. They are named after the tenacious grip of the limpet. Different limpet species exhibit different overall shapes of their teeth. Henry Limpet, a shy bookkeeper, loves fish with a passion. Some species of limpet live in fresh water, but these are the exception. One was "The Incredible Mr. Limpet" (1964), a combined live action & animation feature. Other reports suggested that the attacks may have involved limpet mines.