【Reading】はるつげうお

【English Name】Pacific Herring

Harutsugeuo (the spring-announcing fish) is an old name for the Pacific herring (nishin). With the scientific name Clupea pallasii, it is a saltwater fish belonging to the family Clupeidae of the order Clupeiformes, with a body length of about 30–35 cm. The back is a dark, somber blue-black, and the belly wears a silvery-white luster.

As the name indicates, it derives from the fact that, when spring arrives, the fish appear in schools in the waters near Hokkaido to spawn. It prefers cold seas for its migration and inhabits a wide range including the North Pacific and the Sea of Japan. Within Japan, the southern limit of its distribution is said to be around Toyama Prefecture on the Sea of Japan side, and around Cape Inubo on the Pacific side.

In sushi it is handled as a shiny-skinned fish (hikarimono), and high-freshness individuals are formed into nigiri as sashimi. It carries the most fat in early spring, ahead of spawning, becoming the flavor of the season (shun). Besides being suited to grilling and frying, processed products such as kobu-maki (kelp rolls) and minced-removed herring (migaki-nishin) are also varied, and "kazunoko" (herring roe), made by salting the eggs, has become established as a standard New Year ingredient.

In the Meiji era, herring fishing reached its peak in Hokkaido, and in 1897 there was a record-breaking landing of 975,000 tons. The net-bosses who gained enormous profits built lavish mansions called "nishin goten" (herring palaces), but in the 1950s the catch plummeted. Changes in seawater temperature and overfishing are cited as causes, but a definitive explanation has still not been reached. As a seasonal word (kigo) it is classified under spring and has been frequently composed in haiku.