Plecoglossus altivelis (Ayu, Sweetfish) is an amphidromous fish, spawning in the lower reaches of rivers, with juveniles developing in estuaries, and then moving upriver. Adults reach 300-400 mm, and may die after spawning or spawn multiple times. This fish feeds largely on algae, and so does not compete with other salmonids. Plecoglossus altivelis is native to coastal Asia (Japan, China, Korea, Taiwan), and coastal waters, where it is a highly regarded foodfish (Froese and Pauly 2014). In 1961, 3,250,000 eggs and fry were stocked in the Eel River, California, and additional stockings were made in nearby reservoirs. However, no survivors were seen.