Ayu

Ayu are slender, olive-silver fish with a yellow patch behind the gill, a comb-like set of teeth for scraping algae and a melon-like scent that gives them the name sweetfish. They are native to Japan, Korea, Taiwan and coastal China, hatching in autumn in lower rivers, drifting to sea for the winter and running back upstream in spring to graze algae-covered rocks in clear, fast reaches. Each fish defends a feeding territory, which is the basis of Japanese tomozuri fishing: a live ayu on a line provokes a wild fish to attack, snagging it on trailing hooks. Ayu fishing is a cultural event in Japan, drawing hundreds of thousands of anglers each summer.