The term hake refers to various fish in the families Gadidae (subfamily Phycinae ) and Merlucciidae (both subfamilies Merlucciinae and Steindachneriinae ).

Merluccius bilinearis - Silver Hake
Silver Hake grows to a length of 30 inches (75 cm) and up to 5 lb (2.3 kg). It has a brown coloration with some silvery irridescence fading into pure silver on the belly. It also has 5-7 dark, irregular, vertical bars. It is usually found on or near the bottom in deep water of the continental shelf from Maryland to the Newfoundland Banks. It has a good flavor, but the taste deteriorates rapidly after being caught, and is not a sport fish. Therefore, it is only taken as bycatch in the commercial fisheries.

Merluccius productus - Pacific Hake
Pacific hake grows to a length of 3 feet (about 90 cm). The coloration is metallic silver-gray with black speckling and pure silver on the belly. It is found in open sea at any depth up to 500 fathoms (900 m), from Sea of Cortez to the Gulf of Alaska. It feeds on shrimp, plankton and smaller fishes. It spawns in January through June. There is a commercial fishery for Pacific hake. The Russians eat large numbers of them, and in the United States they're used for animal food.

Urophycis chuss - Red Hake
Red hake grows to 30 inches (75 cm) and 7 lb (3.2 kg). Their coloration is red to olive-brown, or even black above, the sides are tinted yellow, and the belly is white. In this genus, the pelvic fins are long and filamentous, containing tactile and taste senses that they use to search for food in the mud and silt that they are found over, in depths of 6 to 60 fathoms (10 to 110 m). Their range is from Cape Hatteras to Nova Scotia. They are caught commercially, but not considered a prized food fish due to having quite soft flesh.

Urophycis tenuis - White Hake
White hake grows to 4 feet (1.2 m). The coloration is purplish brown on the back, fading to a dirty white beneath. Habits, range and commercial value are the same as in the red hake.

An old European source mentions a hake that was transplanted from the coast of Ireland to Cape Cod. It is uncertain which species this is, but the reference is given below:

This is an Irish salt water fish, similar in appearance to the tom cod. In Galway bay, and other sea inlets of Ireland, the hake is exceedingly abundant, and is taken in great numbers. It is also found in England and France. Since the Irish immigration to America, the hake has followed in the wake of their masters, as it is now found in New York bay, in the waters around Boston, and off Cape Cod. Here it is called the stock fish, and the Bostonians call them poor Johns. It is a singular fact that until within a few years this fish was never seen in America. It does not grow so large here as in Europe, though here they are from ten to eighteen inches [250 to 460 mm] in length. The general color of this fish is a reddish brown, with some golden tints - the sides being of a pink silvery luster.