Anago vs Unagi — Sea Eel vs Freshwater Eel
Japan-wide — anago from Tokyo Bay (Edomae tradition); unagi from various freshwater sources
Japanese eel cuisine distinguishes sharply between two different eel species used in fundamentally different ways. Unagi (freshwater eel, Anguilla japonica): the prestige eel, high-fat, rich, deep-flavoured, prepared as kabayaki (split, steamed, grilled with tare) — associated with summer vitality, extremely expensive, critically endangered. Anago (conger eel, Conger myriaster): the sea eel, available from Tokyo Bay and all Japanese coasts, lower in fat than unagi, more delicate in flavour, and traditionally the eel of Edomae sushi. Anago is prized for its melt-in-mouth tenderness and delicate sweetness when steamed and cooled — a top-tier sushi topping (nigiri anago) typically brushed with tsume (reduction of the eel's cooking liquid and soy) rather than wasabi. Anago is also prepared in similar kabayaki style (simmered and grilled) as a more affordable eel alternative. The two are genuinely different flavour experiences — unagi is richer, more assertive; anago is more delicate and sea-forward.