Japanese anglers’ best-loved river fish are the iwana char, yamame landlocked trout and ayu sweetfish (pictured above and below). The iwana inhabits the narrow, upper reaches of mountainous clear rivers, followed by yamame where the river widens, and the deepest-water dwelling ayu.
The iwana is found only in Hokkaido, Honshu and Shikoku not in Kyushu. It is called ‘rock-fish’ after the boulder-strewn mountain rivers capes it inhabits. As tasty as yamame, it is best in late spring and early summer. It is fantastic as shioyaki, served with sansho. It can also be served as kara'age dusted in flour and deep-fried and kanro-ni, a sweetened simmered dish similar to tsukudani, using glutinous starch syrup.
Yamame means ‘mountain girl’. It is a beautifully marked freshwater version of both the saltwater sakura-masu cherry salmon or the biwa-masu identified by two red spots on its body. Around 30cm in length, it is in season from early summer to autumn. Often it is just plainly grilled without salt as shioyaki and dipped in shoyu. It breeds in pure waters lower down the river than the iwana, but as the English name suggests, never makes it down to the sea.
Yamame is best when caught in late spring or early summer. Furusato, a small soba buckwheat soba and inaka ryori country cuisine specialist in Tokose village in Northern Hyogo prefecture (pictured here, above), serves some of the sweetest yamame - and best soba - I have ever tasted. They are grilled on skewers - still alive, but not for long - over an open irori hearth. If you visit, tell the owner Taniguchi-san 'I say hi'. He knows me as the 'hen na gaijin': the peculiar foreigner. He delights in calling me that, and I don't mind at all. Too true.
The Japanese character for ayu sweetfish consists of two elements, ‘sakana’ fish and ‘uranau’ meaning ‘fortune telling’. This bizarre nomenclature originates in Japan’s distant past when the mythical Empress Jingu, enroute for Korea, caught an ayu on Tamashima, in Matsu’ura. The empress decided this was auspicious, and that Korea would be defeated. History doesn’t record whether the fortune-telling fish was right.
Japanese gourmets love the ayu's konowata, its stinky and bitter-tasting guts. Their unique taste and smell arise because the ayu feed on freshwater algae, and that aroma is retained in the entrails of the fish. Tempted? I've grown to like konowata but it took me many years of trying. I find that a cold glass of slightly sweet sake is the perfect foil for the super-bitter shock to the palate.
Country folk distinguish natural ayu from cultivated ayu by their longer, more pointy chins needed to root out that riverbed algae. Ayu is usually served salted and grilled as shioyaki, especially with tadesu water pepper vinegar, furai and ayu no sugata-zushi.
Masu pink salmon is a favourite of Hokkaido, where the largest specimens reach up to 60cm. Its freshwater variety, kawa-masu brook trout, is also called hime-masu ‘princess trout’ or niji-masu ‘rainbow trout’. Usually it is served as shioyaki, teriyaki or furai.
An import from China but now found in rivers and lakes country wide, funa crucian carp is best known as the ingredient in Shiga Prefecture's splendidly stinky, fermented funa-zushi carp sushi. America's 'fermentation guru' Solomon Katz recently travelled from the States to Shiga Prefecture just to sample its powerfully smelly charms. Buna's proper name is actually gengoro-buna, though few ever use the phrase. Shiga people call it ma-buna, and Shiga anglers nickname it herabuna. Being fermented, funazushi is available year-round. If you'd like to try it in situ, the south-west side Lake Biwa is easy to access from Kyoto. It's a 20-minute train ride.
The shishamo Japanese capelin, or smelt is an izakaya traditional restaurant-cum-bar favourite, not least in south-eastern Hokkaido, where it spawns in estuarine waters from October to November. Komochi shishamo the female fish bearing roe are prized for their tastiness. Usually sold salt-dried, they make excellent, inexpensive shioyaki (an izakaya menu favorite), tempura and furai. A larger species is the Karafuto shishamo Pacific capelin.