Heterololigo bleekeri, commonly known as the spear squid, is a species of coastal squid in the family Loliginidae distributed in the northwest Pacific Ocean, particularly around Japan, Korea, and eastern China. The genus name Heterololigo combines Greek hetero- (“different”) with Loligo, a classical Latin name for squid, while the species epithet bleekeri honors the 19th-century Dutch ichthyologist Pieter Bleeker, who contributed extensively to the study of Indo-Pacific marine fauna. The common name comes from its sharp elongated mantle, which is shaped like a spearhead.

Heterololigo bleekeri inhabits shallow coastal and shelf waters, where it forms seasonal populations and undertakes spawning migrations. Like other loliginid squids, it has an elongated mantle, a pair of triangular fins, and eight arms with two longer tentacles used for capturing prey such as small fish and crustaceans. It is an active predator and plays an important ecological role in marine food webs as both predator and prey.

Heterololigo bleekeri is valued for its tender flesh and mild, slightly sweet flavor. It is widely consumed in Japanese cuisine in forms such as sashimi, sushi toppings, grilled preparations, simmered dishes, and tempura. The mantle, arms, and tentacles are all edible, and different parts may be prepared in distinct ways depending on texture. Fresh squid is particularly prized for its translucency and delicate bite, while processed forms include dried squid and fermented products in some regional traditions.

Nutritionally, the flesh of Heterololigo bleekeri is high in protein and low in fat, containing essential amino acids and relatively low caloric density. It is a notable source of taurine, a sulfur-containing amino acid involved in cardiovascular and neurological function, as well as minerals such as selenium, copper, and phosphorus. Like other cephalopods, it contains cholesterol in moderate amounts and small quantities of omega-3 fatty acids. Bioactive compounds include taurine and peptides formed during digestion or processing, which have been studied for antioxidant and metabolic effects.