The main producing areas of capelin are in the cold-water seas of the North Atlantic and the North Pacific.

Capelin is a small cold-water fish, scientific name Mallotus villosus, named for the large amount of roe often carried in its belly; in Cantonese, "chun" refers to fish roe, hence the name capelin. It has a slender body, usually only a dozen or so centimeters long, with a silvery-white body, tender flesh, and plump roe, and the whole fish can be eaten. It is commonly grilled or deep-fried.

Capelin is mainly distributed in the cold-water seas of the North Atlantic, the North Pacific and near the Arctic Ocean, and is a typical high-latitude commercial fish. Most capelin on the market comes from coastal fishing grounds in countries such as Canada, Norway, Iceland and Russia, and similar species are also produced in the Hokkaido area of Japan. Capelin caught in different sea areas differs slightly in appearance and taste, but the overall quality is fairly similar.

Because the fishing grounds are far from the main consumer markets, capelin is mostly circulated in the form of frozen or salted processed products, and frozen products are the most common on the domestic market. When selecting, look for products with intact bodies, plump roe and no obvious off odor, and keep them at low temperature during storage to avoid affecting the taste.

As for common questions, many people wonder whether the roe inside the capelin can be eaten; the answer is yes, the roe is exactly what makes it distinctive, and eating the whole fish gives an even better flavor. In addition, the supply and availability of capelin fluctuate with the fishing season, so when buying it is advisable to choose reputable channels and judge by freshness and appearance.