Tachiuo

A long, silver, blade-shaped fish with no scales, instead coated in a silvery film that's eaten right along with the skin. Salt-grilled or pan-fried, the skin turns aromatic while the fatty flesh flakes soft — and larger fish are said to run fattier still. It peaks in autumn as the water starts to cool, and raw, it has a distinctive sticky texture unlike most white fish.

Its sharp teeth can cut through tackle if it thrashes, so pole-and-line fishing calls for careful rigging and handling. Fish are iced immediately after landing to preserve freshness and keep that silvery film from flaking off, and because it needs no scaling, it's simple to prepare whole for salt-grilling; sashimi gets fine, hone-kiri-like scoring to make it easier to eat.

Fish swimming near the Kuroshio current tend to grow larger, and in grounds facing that current, like those off Ibusuki in Kagoshima, boats have long targeted big beltfish by pole-and-line. Though strongly migratory, grounds closer to the Kuroshio are said to draw fish that are both larger and fattier — the strength of the warm current translating almost directly into the size of the fish.