Ayu, Moroko, and the Freshwater Fish Culture of Lake Biwa

Lake Biwa has supported freshwater fishing communities for centuries, and several species eaten here exist nowhere else, including the tiny minnow-like fish called honmoroko, a small member of the carp family and various small ayu (sweetfish) populations. These fish are generally small, bony, and intensely flavored rather than meaty, which shapes how they're cooked — quick and assertive rather than delicate.

Common preparations include tsukudani, where small fish are simmered slowly in soy sauce, sugar, and mirin until sweet, dark, and shelf-stable, and simple grilling with salt for slightly larger fish like ayu. These are sold in small packets at local markets and souvenir shops around the lake, often labeled by species, and make a more portable, less intense introduction to Biwa's fish culture than funazushi.