
The alewife is an anadromous species of herring found in North America. It is one of the "typical" North American shads, attributed to the subgenus Pomolobus of the genus Alosa. As an adult it is a marine species found in the northern West Atlantic Ocean, moving into estuaries before swimming upstream to breed in freshwater habitats, but some populations live entirely in fresh water. It is best known for its invasion of the Great Lakes by using the Welland Canal to bypass Niagara Falls. Here, its population surged, peaking between the 1950s and 1980s to the detriment of many native species of fish. In an effort to control them biologically, Pacific salmon were introduced, only partially successfully. As a marine fish, the alewife is a US National Marine Fisheries Service "Species of Concern".
The American paddlefish is a species of basal ray-finned fish closely related to sturgeons in the order Acipenseriformes. Fossil records of paddlefish date back over 125 million years to the Early Cretaceous. The American paddlefish is a smooth-skinned freshwater fish commonly called paddlefish, and is also referred to as Mississippi paddlefish, spoon-billed cat, or spoonbill. It is the only living species in the paddlefish family, Polyodontidae. The other recently-surviving member of this lineage is the possibly now extinct Chinese paddlefish endemic to the Yangtze River basin in China. The American paddlefish is often referred to as a primitive fish or a relict species because it retains some morphological characteristics of its early ancestors, including a skeleton that is almost entirely cartilaginous and a paddle-shaped rostrum (snout) that extends nearly one-third their body length. It has been referred to as a freshwater shark because of its heterocercal tail or caudal fin resembling that of sharks. The American paddlefish is a highly derived fish because it has evolved with adaptations such as filter feeding. Its rostrum and cranium are covered with tens of thousands of sensory receptors for locating swarms of zooplankton, which is their primary food source.

Arctic cisco is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of Ireland, known as the pollan, alternatively regarded as conspecific with it, or as a distinct species.

Arctic grayling is a species of freshwater fish in the salmon family Salmonidae. T. arcticus is widespread throughout the Arctic and Pacific drainages in Canada, Alaska, and Siberia, as well as the upper Missouri River drainage in Montana. In the U.S. state of Arizona, an introduced population is found in the Lee Valley and other lakes in the White Mountains. They were also stocked at Toppings Lake by the Teton Range and in various lakes in the high Uinta Mountains in Utah, as well as various alpine lakes of the Boulder Mountain chain in central Idaho.

Artedius harringtoni, also known as the Scalyhead sculpin or Plumose sculpin, is a demersal species of sculpin in the family Cottidae. The species is native to the eastern Pacific.

The Athabasca rainbow trout is a localized variety of the rainbow trout, a fish in the family Salmonidae. It is found in the headwaters of the Athabasca river in Alberta Canada. The Athabasca rainbow trout was considered as a form of the Columbia River redband trout (O. mykiss gairdneri) subspecies in the trout handbook of Robert J. Behnke (1992), but considered a separate, yet unnamed subspecies by L. M. Carl of the Ontario Ministry of Resources in work published in 1994. The Athabasca River is a tributary of the Mackenzie River system which flows north into the Arctic Ocean.

The black crappie is a freshwater fish found in North America, one of the two crappies. It is very similar to the white crappie in size, shape, and habits, except that it is darker, with a pattern of black spots.

The brassy minnow is a species of fish belonging to the family Cyprinidae. The family Cyprinidae consists of mainly freshwater minnows and carps. The fish gets its scientific name from the Greek word Hybognathus, meaning bulging jaw, and hankinsoni from the American scientist, T.L. Hankinson. It is commonly found throughout the northern United States and Canada.

The brown bullhead is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead and yellow bullhead. It was originally described as Pimelodus nebulosus by Charles Alexandre Lesueur in 1819, and is also referred to as Ictalurus nebulosus.

The yellow bullhead is a species of bullhead catfish that is a ray-finned fish that lacks scales.

The lake chub is a freshwater cyprinid fish found in Canada and in parts of the United States. Of all North American minnows, it is the one with the northernmost distribution. Its genus, Couesius is considered monotypic today. The genus was named after Dr. Elliott Coues, who collected the holotype specimen.

The Coastrange sculpin is a freshwater sculpin of the genus Cottus. They are commonly found near the ocean in western North America, namely Canada and the United States. It is also known as the Aleutian sculpin.

Coregonus artedi, commonly known as the cisco, is a North American species of freshwater whitefish in the family Salmonidae. The number of species and definition of species limits in North American ciscoes is a matter of debate. Accordingly, Coregonus artedi may refer either in a narrow sense to one of the several types of cisco found e.g. in the Great Lakes, or in a broad sense to the complex of all ciscoes in continental North American lakes, Coregonus artedi sensu lato.

Eastern blacknose dace is a species of ray-finned fish in the genus Rhinichthys. Its name originates from the Old French word "dars" which is the nominative form of the word "dart" in reference to their swimming pattern. The western blacknose dace formerly was considered conspecific. While morphologically the two species are not significantly different, they are allopatric. The eastern blacknose dace is found across the southeast portion of Canada and down along the United States' east coast. It is dark brown to olive on its dorsal surface and silvery white below, the two shades separated by the darkly pigmented lateral line. In the breeding season, males develop darker pigmentation and an orange lateral line. Blacknose dace live in rocky streams and rivers where they feed upon small invertebrates and microscopic biological matter and provide forage for larger fish.

The emerald shiner is one of hundreds of small, silvery, slender fish species known as shiners. The identifying characteristic of the emerald shiner is the silvery emerald color on its sides. It can grow to 3.5 inches in length and is found across North America from Canada to the Gulf of Mexico, commonly in large, deep lakes and rivers, though sometimes in smaller bodies of water as well. It feeds on small organisms such as zooplankton and insects, congregating in large groups near the surface of the water. It is a quite common fish and is often used as a bait fish.

The flathead chub is a species of fish in the carp family, Cyprinidae. It is the only member of the monotypic genus Platygobio. It is native to North America, where it is distributed throughout central Canada and the central United States.

The hornyhead chub is a small species of minnow in the family Cyprinidae of order Cypriniformes. It mainly inhabits small rivers and streams of the northern central USA, up into Canada. The adults inhabit faster, rocky pools of rivers.
The banded killifish is a North American species of temperate freshwater killifish belonging to the genus Fundulus of the family Fundulidae. Its natural geographic range extends from Newfoundland to South Carolina, and west to Minnesota, including the Great Lakes drainages. This species is the only freshwater killifish found in the northeastern United States. While it is primarily a freshwater species, it can occasionally be found in brackish water.

The kokanee salmon, also known as the kokanee trout, little redfish, silver trout, kikanning, Kennerly's salmon, Kennerly's trout, or Walla, is the non-anadromous form of the sockeye salmon. There is some debate as to whether the kokanee and its sea-going relative are separate species; geographic isolation, failure to interbreed, and genetic distinction point toward a recent divergence in the history of the two groups. The divergence most likely occurred around 15,000 years ago when a large ice melt created a series of freshwater lakes and rivers across the northern part of North America. While some members of the salmon family (salmonids) went out to sea (anadromous), others stayed behind in fresh water (non-anadromous). The separation of the sockeye and the kokanee created a unique example of sympatric speciation that is relatively new in evolutionary terms. While they occupy the same areas and habitats during the breeding season, when ocean-going sockeye salmon return to freshwater to spawn, the two populations do not mate with each other in some regions, suggesting speciation.

The lake lamprey, Entosphenus macrostomus, also known as the Vancouver lamprey or Cowichan lamprey, a recent derivative of the pacific lamprey, is a species of freshwater lamprey endemic to two North American lakes: Lake Cowichan and Mesachie Lake in Vancouver Island, Canada. The lamprey was originally called the Vancouver Island lamprey, until an error in filing shortened it to the Vancouver lamprey. The alternate common name of "Cowichan lamprey" was coined and promoted by the species' describer, Dr. Dick Beamish, who originally identified the species in the 1980s.

The northern brook lamprey is a freshwater fish in the family Petromyzontidae. It is closely related to the silver lamprey and may represent an ecotype of a single species with I. unicuspis.

The sea lamprey is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish."

Madtoms are freshwater catfishes of the genus Noturus of the family Ictaluridae. It is the most species-rich family of catfish in North America, native to the central and eastern United States, and adjacent parts of Canada. Their fin spines contain a mild venom with a sting comparable to that of a honey bee.

The mummichog is a small killifish found along the Atlantic coast of the United States and Canada. Also known as Atlantic killifish, mummies, gudgeons, and mud minnows, these fish inhabit brackish and coastal waters including estuaries and salt marshes. The species is noted for its hardiness and ability to tolerate highly variable salinity, temperature fluctuations from 6 to 35 °C, very low oxygen levels, and heavily polluted ecosystems. As a result, the mummichog is a popular research subject in embryological, physiological, and toxicological studies. It is also the first fish ever sent to space, aboard Skylab in 1973.

The muskellunge (Esox masquinongy), often shortened to muskie, musky or lunge, is a species of large freshwater fish native to North America. It is the largest member of the pike family, Esocidae.

The Pacific cod, Gadus macrocephalus, is a species of ray-finned fish in the family Gadidae. It is a bottom-dwelling fish found in the northern Pacific Ocean, mainly on the continental shelf and upper slopes, to depths of about 900 m (3,000 ft). It can grow to a length of a meter or so and is found in large schools. It is an important commercial food species and is also known as gray cod or grey cod, and grayfish or greyfish. Fishing for this species is regulated with quotas being allotted for hook and line fishing, pots, and bottom trawls.

The Pacific sleeper shark is a sleeper shark of the family Somniosidae, found in the North Pacific on continental shelves and slopes in Arctic and temperate waters between latitudes 70°N and 22°N, from the surface to 2,000 metres (6,600 ft) deep. Records from southern oceans are likely misidentifications of relatives. Its length is up to 4.4 m (14 ft), although it could possibly reach lengths in excess of 7 m (23 ft).

The northern pike is a species of carnivorous fish of the genus Esox. They are typical of brackish and fresh waters of the Northern Hemisphere. They are known simply as a pike in Britain, Ireland, and most of Eastern Europe, Canada and the United States.

Tetronarce californica also known as the Pacific electric ray is a species of electric ray in the family Torpedinidae, endemic to the coastal waters of the northeastern Pacific Ocean from Baja California to British Columbia. It generally inhabits sandy flats, rocky reefs, and kelp forests from the surface to a depth of 200 m (660 ft), but has also been known to make forays into the open ocean. Measuring up to 1.4 m (4.6 ft) long, this species has smooth-rimmed spiracles and a dark gray, slate, or brown dorsal coloration, sometimes with dark spots. Its body form is typical of the genus, with a rounded pectoral fin disc wider than long and a thick tail bearing two dorsal fins of unequal size and a well-developed caudal fin.

The redside shiner is a species of cyprinid fish found in the western United States and Canada.

Semotilus atromaculatus, known as the creek chub or the common creek chub, is a small minnow, a freshwater fish found in the eastern US and Canada. Differing in size and color depending on origin of development, the creek chub can usually be defined by a dark brown body with a black lateral line spanning horizontally across the body. It lives primarily within streams and rivers. Creek Chubs attain lengths of 2-6 inches with larger specimens of up to 12 inches possible. The genus name Semotilus derives from the Greek word sema, and atromaculatus comes from the Latin word "black spots".

The golden shiner is a cyprinid fish native to eastern North America. It is the sole member of its genus. Much used as a bait fish, it is probably the most widely pond-cultured fish in the United States. It can be found in Quebec and its French name is "Mené jaune" or "Chatte de l'Est".

The shortjaw cisco is a North-American freshwater whitefish in the salmon family. Adult fish range to about 30 cm (12 in) in length and are silver, tinged with green above and paler below. One of the members of the broader Coregonus artedi complex of ciscoes, it is distributed widely in the deeper lakes of Canada, but populations in the Great Lakes have been declining and it is no longer present in Lakes Michigan, Huron, and Erie. It feeds mainly on crustaceans and insect larvae and spawns in the autumn on the lake bed. It is part of the important cisco (chub) fishery in the Great Lakes. The International Union for Conservation of Nature has rated its conservation status as "vulnerable". Shortjaw cisco have however evolved from the cisco Coregonus artedi independently in different lakes and different parts of the range, and conservation assessments therefore should be made on a lake-wise rather than range-wide basis.

The shortnose sturgeon is a small and endangered species of North American sturgeon. The earliest remains of the species are from the Late Cretaceous Period, over 70 million years ago. Shortnose sturgeons are long-lived and slow to sexually mature. Most sturgeons are anadromous bottom-feeders, which means they migrate upstream to spawn but spend most of their lives feeding in rivers, deltas and estuaries. The shortnose sturgeon is often mistaken as a juvenile Atlantic sturgeon, because of their small size. Prior to 1973, U.S. commercial fishing records did not differentiate between the two species, both were reported as "common sturgeon", although it is believed based on sizes that the bulk of the catch was Atlantic sturgeon. The shortnose is distinguishable from the Atlantic sturgeon due to its shorter and rounder head.

The silver redhorse is a species of freshwater fish endemic to Canada and the United States. Sometimes called redhorse or sucker for short, the it is in the family Catostomidae with other suckers. The species is distributed from Quebec to Alberta and is also in the Mississippi River, St. Lawrence River, Ohio River, and the Great Lakes basins.

Raja stellulata, commonly known as the Pacific starry skate, rock skate, prickly skate, or starry skate, is a species of cartilaginous fish in the family Rajidae. It is found on rocky bottoms at 18–982 m depths in the Northeast and Eastern Central Pacific, from Coronado Bank in northern Baja California in Mexico to Barkley Sound in British Columbia, Canada. Females reach a maximum total length of 76.1 cm and a maximum age of 15 years, while males can be up to 71.7 cm long and live up to 14 years; the total length at birth is 15.5–22.5 cm. This skate prefers cold water with a temperature of 4.1–11.6°C.

The ninespine stickleback, also called the ten-spined stickleback, is a freshwater species of fish in the family Gasterosteidae that inhabits temperate waters. It is widely but locally distributed throughout Eurasia and North America. Despite its name, the number of spines can vary from 8 to 12.

The blackstripe topminnow, Fundulus notatus, is a small freshwater fish in the family Fundulidae, found in central North America.

The cutthroat trout (Oncorhynchus clarkii) is a fish species of the family Salmonidae native to cold-water tributaries of the Pacific Ocean, Rocky Mountains, and Great Basin in North America. As a member of the genus Oncorhynchus, it is one of the Pacific trout, a group that includes the widely distributed rainbow trout. Cutthroat trout are popular gamefish, especially among anglers who enjoy fly fishing. The common name "cutthroat" refers to the distinctive red coloration on the underside of the lower jaw. The specific name clarkii was given to honor explorer William Clark, coleader of the Lewis and Clark Expedition.
The rainbow trout is a trout and species of salmonid native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead is an anadromous (sea-run) form of the coastal rainbow trout (O. m. irideus) or Columbia River redband trout (O. m. gairdneri) that usually returns to fresh water to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead.
The westslope cutthroat trout, also known as the black-spotted trout, common cutthroat trout and red-throated trout is a subspecies of the cutthroat trout and is a freshwater fish in the salmon family of order Salmoniformes. The cutthroat is the Montana state fish. This subspecies is a species of concern in its Montana and British Columbia ranges and is considered threatened in its native range in Alberta.

The walleye, also called the yellow pike or yellow pickerel, is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relative of the European zander, also known as the pikeperch. The walleye is sometimes called the yellow walleye to distinguish it from the blue walleye, which is a subspecies that was once found in the southern Ontario and Quebec regions, but is now presumed extinct. However, recent genetic analysis of a preserved (frozen) 'blue walleye' sample suggests that the blue and yellow walleye were simply phenotypes within the same species and do not merit separate taxonomic classification.

The mountain whitefish is one of the most widely distributed salmonid fish of western North America. It is found from the Mackenzie River drainage in Northwest Territories, Canada south through western Canada and the northwestern USA in the Pacific, Hudson Bay and upper Missouri River basins to the Truckee River drainage in Nevada and Sevier River drainage in Utah.

The round whitefish is a freshwater species of fish that is found in lakes from Alaska to New England, including the Great Lakes. It has an olive-brown back with light silvery sides and underside and its length is generally between 9 and 19 inches. They are bottom feeders, feeding mostly on invertebrates, such as crustaceans, insect larvae, and fish eggs. Some other fish species, like white sucker in turn eat their eggs. Lake trout, northern pike and burbot are natural predators. Other common names of the round whitefish are Menominee, pilot fish, frost fish, round-fish, and Menominee whitefish. The common name "round whitefish" is also sometimes used to describe Coregonus huntsmani, a salmonid more commonly known as the Atlantic whitefish.