Alaska Pollock is part of the Cod family. Its scientific name was recently changed to Gadus chalcogrammus from Theragra chalcogramma, to better reflect its close association to its Cod cousin.   
Cod can grow to a maximum size of more than 3 feet but average 12 to 20 inches in length and 1/2 to 2 pounds in weight.
The Alaska pollock fishery is one of the largest, most valuable fisheries in the world. It’s one of the first U.S. fisheries to be managed with catch share and is often considered one of the best managed fisheries in the world.