The Japanese Table
Queen of Freshwater Streamsby Tomoya Akimichi
In the clear currents of the Kakita River, which flows out of the spring-fed wetlands at the foot of Mt. Fuji, one can find schools of ayu (sweetfish) slipping gracefully among the river grasses. This is the fish known in Japan as the "queen of freshwater streams."
There is probably no freshwater fish Japanese are so fond of as ayu. Similar species such as smelt can be found in Europe and the U.S., but the only habitat of ayu is in and around the Japanese archipelago. All ayu that inhabit rivers in Japan are of the same kind except for a small-sized species unique to landlocked Lake Biwa, and the nearly extinct Ryukyu ayu from the Amami Islands (located between Kyushu and Okinawa). From early summer through autumn, ayu are enjoyed from one end of the Japanese archipelago to the other.
The life cycle of the ayu is very short. Even if not caught in the angler's net, they live only about one year, hence its name since ancient times: nen-gyo, or "year-fish." The ayu of the Kakita River spawn in the pebble-bedded lower reaches of the larger Kano River in late autumn. After hatching, the fry migrate out to sea, sheltering in coastal areas until the following spring. Toward the end of March, they head back to the mouth of the Kano and push upstream. Those that end up in the nets of coastal round haul fishermen are sent to fish farms, where they are fed and supplied with ample oxygen. They are nurtured with skilled professional care until the ayu fishing season opens in June, then released. Anglers pay license fees to enjoy fishing local streams between June and mid-September.
The ayu that safely return to inland waters, meanwhile, ascend to the middle reaches of the Kano River and settle there. They feed on algae on the river bottom, scraping it off the rocks with their saw-shaped teeth. Ayu establish their own territory and protect it against intrusion, attacking and driving away other ayu that attempt to enter.
Fishing for Ayu
Humans take advantage of the fish's territorial instincts by attaching a live ayu to a hook and dropping into the territory of another. When the defender comes out to attack, it is caught on a separate hook. This live-lure fishing method is called tomo-zuri and is used today in almost all rivers inhabited by ayu; historical documents reveal that this method was developed near Kyoto some three hundred years ago, during the Edo period (1603-1867). The most exciting moment in live-lure fishing is when the angler feels a strong tug on the fish line. The more powerful the ayu's attack, the stronger the tug, the greater the fisherman's satisfaction.
While live-lure fishing is popular among anglers, another traditional method of catching ayu employs cormorants and is known as ukai. Cormorant fishing is usually practiced during summer at night, from boats carrying torches. Cormorants collared with hand ropes dive into the river and capture fish attracted by the torchlight, but disgorge their catch under the fishermen's skillful technique. Today this method is used in a very few places in the country.
Since ancient times, ayu caught by cormorant fishing on the Katsura River near Kyoto were presented to the Imperial Court. Even today, ayu caught by this method on the Nagara River in Gifu Prefecture are presented to the emperor. But the purpose of cormorant fishing is not just to present gifts to royalty, but to support the livelihood of the fishermen. Today the practice thrives as a tourist industry, as sightseers watch the fishing from nearby covered boats.
Ayu were not only presented to the Imperial Court, they were among the fish caught in rivers near Kyoto and Edo (present-day Tokyo) that were delivered to the cities as Shinto shrine offerings and gifts. The fish were also given to the daimyo (territorial lords) and shogunate as goods acceptable for payment of taxes during the Edo period.
The "Aromatic Fish"
After returning from the sea, ayu mature (to about 30cm or 12 inches) in the river in summer and early autumn, then descend to the lower reaches of the river. In the past, weirs were often set to catch those fish ascending the river in early summer and descending in autumn. Male and female ayu mate there, and after spawning, both male and female die.
Few fish are so sought after by humans from the fry stage to just before they die naturally. Various methods of cooking ayu have been developed since ancient times, but one favorite is by simply roasting the fish with salt over hot coals. The fish is skewered and salted, particularly on its fins and head, and roasted using charcoal—preferably a type with very high caloric heat. The flesh has a light taste and the bones are soft and edible. The delicious aroma that accompanies the taste comes from the algae on which the ayu feed; indeed, ayu are also known as the "aromatic fish" (ko-gyo).
Other preparations include fire-dried ayu; salt-preserved ayu; ayuzushi (fermented ayu and rice); uruka (ovaries, spermary and other internal organs preserved in salt); and segoshi namasu (ayu sashimi with vinegared miso). Dried ayu are also used for making the broth of various noodle dishes, enjoyed especially during the heat of summer.
Ayu caught with full egg sacs just before spawning, rolled in konbu (giant kelp), and boiled with soy sauce and other seasonings is a local specialty of the Lake Biwa area, as well as a popular gift. The small ayu of Lake Biwa cooked in a sweet soy sauce glaze are also a favorite delicacy. One of few varieties of freshwater fish that are flavorful and can be eaten bones and all, ayu are among the leading delicacies of Japanese cuisine.
Ayu have also long been the inspiration for Japanese-style confections. Sweets in the shape of ayu are found throughout the country. A noted seasonal sweet of Kyoto, for example, is an ayu-shaped sponge cake stuffed with sweet green-bean jam. Similar confections are considered regional and seasonal specialties elsewhere: in Ohito, an area noted for ayu angling along the Kano River, one may savor the local ayu confection. It is the epitome of subtle flavoring, not too sweet and faintly evocative of the presence of ayu.
Tomoya Akimichi is one of Japan's leading maritime anthropologists. He is currently a professor at the National Museum of Ethnology in Osaka, where his main areas of study focus on Southeast Asia, Oceania and Japan. He is the author of various books and articles on fishing and maritime culture.