Theragra

Theragra is a genus of cod-like fishes in the family Gadidae. It has often been treated as a distinct genus, though in some classifications it is regarded as a subgenus of Gadus. The mostWell-known species is Theragra chalcogramma, commonly called the Alaska pollock or walleye pollock; in some taxonomic schemes it is placed as Gadus chalcogrammus.

Distribution and habitat: Species assigned to Theragra are found in the North Pacific Ocean, including the Bering Sea, the Gulf of Alaska, and surrounding continental shelf waters. They inhabit cold, nutrient-rich pelagic and outer-shelf environments and typically form large schools during much of the year.

Biology and ecology: Alaska pollock is a relatively fast-growing, short-lived gadid. Spawning occurs in winter and spring in productive waters, with larvae and juveniles dispersing to nurseries as they develop. Adults feed on a variety of prey, including smaller fish and crustaceans, and they undertake seasonal migrations related to temperature, prey availability, and spawning.

Fisheries and conservation: Alaska pollock is one of the world’s most commercially important fish species, supporting large-scale fisheries primarily in U.S. and Russian waters. Stock assessments guide catch quotas and management measures implemented by regional authorities and international agreements. The species has been subject to sustainability evaluations by third-party organizations, and management aims to minimize ecological impact while maintaining harvests. Bycatch and ecosystem effects are considerations in ongoing management efforts.