Spisula sachalinense is a large marine bivalve mollusk in the family Cardiidae, commonly known as the Sakahlin surf clam or hokkigai (ホッキ貝) in Japan. It inhabits cold-temperate sandy seabeds of the northwest Pacific, particularly along the coasts of northern Japan, Sakhalin, and the Russian Far East. The genus name Spisula possibly honors the German zoologist J.B. von Spix, while the species epithet sachalinense refers to Sakhalin Island, one of the regions from which it was originally described. In Japan, the term hokkigai generally refers to this species while in foreign markets the word often refers to the Arctic surf clam (Mactromeris polynyma).

This species burrows in sandy substrates in relatively shallow coastal waters and feeds by filter-feeding suspended plankton and organic particles. It possesses a thick, sturdy shell adapted to wave-exposed environments. As a food source, Spisula sachalinense is highly valued in Japanese cuisine, especially in Hokkaido and northern Honshu. The siphon and mantle tissues are consumed raw as sashimi or sushi topping, lightly blanched to enhance color and sweetness, or cooked in soups and mixed rice dishes. The clam is also commercially harvested and distributed both domestically and internationally.

Nutritionally, the edible tissues are rich in high-quality protein, glycogen (which contributes sweetness), vitamin B₁₂, iron, and other trace minerals. Like many marine bivalves, it may contain bioactive peptides and taurine, which has been studied for cardiovascular and metabolic roles. As a filter feeder, it can accumulate environmental contaminants or marine biotoxins under certain conditions, making regulated harvesting and monitoring important for food safety.