Ayu is a fresh water fish and, like the koi, a symbol of courage and perseverance, because it swims against the current. It is a hard to catch fish and, besides fly fishing, old traditional methods, like cormorant fishing, are still used in some places in Japan.
Ayu is also known as sweet-fish, because of its deliciously sweet taste. One of the most popular cooking methods is to grill it with salt over a charcoal fire (Ayu no shio yaki), like in this photo taken during the New Year's celebrations at the Senso-ji Temple in Tokyo.
EXIF info:
Nikon D90
Lens: 8-16mm F/4.5-5.6G
Focal Length: 16mm
Aperture: F/5.6
Shutter Speed: 1/25s
ISO Sensitivity: ISO 640