Long ago in my youth, I worked on a dive boat in the French Mediterranean (near the Spanish border). When we got hungry during a dive (i.e., often) we used to bring up these tough little crud covered pods that were called violets de mer in French. We would cut them open and eat the bright yellow substance inside, which tasted strongly of iodine. Does anyone know what these things are called in English (or Japanese)? Are they available in U.S. seafood or sushi places?