Ayu. Sweet smelt or freshwater trout. These fish are sometimes caught by cormorants and regurgitated. We attended a kaiseki ryori in Kyoto one May, the right season for these fish. One of the courses consisted of these fish. They were lightly fried and served whole, unlike most of the things which appeared in front of us that night, including raw sea cucumber and something unspeakable called junsai. Our ayu were said to have been of the regurgitated variety.