The salmon family is a diverse group containing many species that we eat on a daily basis. Typically, when one thinks of salmon, they think of fish with pink, flavorful filets but this group also contains many Salmonid species with white flesh, often referred to as “whitefish.”
Although “whitefish” may refer to species of marine or freshwater fish, the taxonomic whitefish family (Coregonidae) includes several species of Salmonid found in different regions of the world, and their specific names and attributes may vary based on location. The Coregonus genus alone contains over 65 species, many of which are important to humans as food fish.
Some Coregonus species like the blackfin cisco (Coregonus nigripinnis), the longjaw cisco (Coregonus alpenae), and the deepwater cisco (Coregonus johannae), are extinct. While the causes of species extinction are complex, many whitefish extinctions coincide with human expansion and settlement in new regions combined with efforts to build dams and use whitefish spawning or migratory habitats for industry or residential purposes. As members of the Salmonidae family, most whitefish are migratory, and the construction of dams along migration routes prevents adults from reproducing and effectively drives many species to extinction. In other words, their migratory nature makes them extremely vulnerable to human activities.
This guide will discuss a fraction of important whitefish species, including those in the genus Coregonus and those commercially considered “whitefish.” Marine whitefish are usually members of the cod family, Gadidae, with three dorsal fins and palatable white filets. These fish sustain huge commercial fisheries and feed a significant portion of the global human population.
Whitefish in the Salmonidae Family
1) Cisco (Coregonus artedi)
The most common Coregonus species is the cisco which is a salmon-like, silvery fish species like its other whitefish relatives. The cisco possesses a small adipose fin after the dorsal fin, they lack teeth, and they have a slight underbite. These characteristics are critical for distinguishing cisco from other similar whitefish species. It also goes by other names like the tulibee or lake herring. Its flesh is edible and cisco filets are usually smoked. An angler can expect to reel in cisco between 11 and 15 inches or 28 to 38 cm with a weight of 0.75 to 1.25 lbs (0.34 to 0.57 kg).
This species’ natural range covers the Great Lakes and expands into Canada. Introductions outside its range into Montana, Wyoming, North and South Dakota, Minnesota, and a handful of states along the east coast have expanded the cisco’s range. Generally, cisco form schools in the depths of large lakes where they hunt as a group. During the cooler winter months, cisco can be found in nearshore areas, but they will retreat deeper into the lakes as these shallow areas warm up in the summer. This seasonal migration is important to their survival as temperatures above 60°F (15.6°C) are lethal for the cisco.
During the late fall, cisco will migrate upstream to spawn, just like their salmon relatives! The cisco’s scientific name is coined after one of the first recognized ichthyologists, Peter Artedi, who published one of the first major works on the classification of fish.
The cisco is of least concern according to the IUCN.
2) Round whitefish (Prosopium cylindraceum)
The round whitefish, also known as the Menominee, can be distinguished from the cisco by observing an orange tint on the fins of mature individuals. As their name suggests, they also have a more tube-like body shape than many other whitefish species. Cisco and lake whitefish have two flaps of skin between their nostrils, whereas round whitefish only have one. The upper jaw of the round whitefish also extends past the lower jaw.
Like the cisco, round whitefish are usually found in deeper lakes where they hunt in schools for aquatic invertebrates like crustaceans, aquatic insect larvae, zooplankton, and bottom-dwelling invertebrates. On average, round whitefish are approximately 8 to 12 inches (20 to 30 cm) in length, although their size varies greatly by locality. During the spawning season, which occurs in the late fall and winter, breeding adults develop prominent tubercles.
3) Mountain whitefish (Prosopium williamsoni)
More common than other trout or salmon species, the mountain whitefish is an abundant silver fish native throughout the northwestern United States with a native range that extends into Idaho, Washington, Oregon, Wyoming, and parts of Canada. Their abundance and small size relative to other trout and salmon species make them the perfect food source for larger carnivores like the rainbow and brown trout.
Mountain whitefish feed primarily from the bottom of lakes, so anglers looking to catch them should use sinkers. They have the highest limit of all trout species, with 20 allowed daily. They are also hunted via spearfishing.
4) Pygmy whitefish (Prosopium coulterii)
This next species is one of the smallest salmonids in North America. Pygmy whitefish are small, silver fish with large eyes. On average, a pygmy whitefish is usually between 4 and 5 inches (10 – 13 cm) long. Pygmy whitefish are difficult to study due to their small size and ability to fit through the mesh of sampling nets, but they are found in the northwestern United States and Canada, as well as Lake Superior.
This species occurs in deep, cold-water lakes and the streams that feed them. Adults take 2 – 3 years to reach sexual maturity. Then, they migrate from lakes to these streams to spawn in the winter. As a small species, they are prey items for larger fish. They also predate upon nuisance insect species like mosquito larvae. During the winter breeding season, adults consume many fish eggs, including eggs from their species.
5) Humpback whitefish (Coregonus pidschian)
The humpback whitefish is unique among whitefish in that it possesses a large hump beginning just behind the eyes. This species is common in rivers throughout Alaska and is commercially harvested for its filets which can be quite large, since this fish can grow up to 20 inches (50.8 cm), although they are more commonly found at around 13 in (33 cm).
The diet of the humpback whitefish includes bottom-dwelling mollusks, crustaceans, and the larvae of aquatic insects. They are abundant wherever they occur and are a vital food source for other wildlife species.
While not mandatory, specific populations of humpback whitefish in streams connected to the ocean will migrate to the sea as juveniles, like salmon. Once they mature, they return to freshwater to reproduce. Adult females produce plenty of young, as many as 50,000 eggs. They return to the same spawning grounds each year.
6) Houting (Coregonus lavaretus oxyrhynchus)
The houting once occupied a range that extended into France, Belgium, Germany, and Denmark but has suffered significant population declines to the point at which it was thought to be extinct. Several Danish subpopulations were recently discovered, giving hope for the survival of this species. Due to this discovery, efforts are underway to reintroduce the houting to its once-occupied habitats and restore existing habitats.
As a salmonid, this species requires clean, unobstructed rivers for spawning, and, as a result, dam construction and pollution along migratory paths and within spawning grounds have resulted in marked population declines of extant C. i. oxyrhynchus populations in the last century.
Like North American salmon, the houting is important in bringing energy from the ocean to freshwater streams where it spawns. Juvenile fish born in freshwater streams migrate to the sea, consuming invertebrates and small fish as they mature into adults. Adult houting then return to their spawning streams to begin the cycle anew. At each stage, predators like the cormorant (Phalacrocorax carbo), larger fish, mammals, and even humans benefit from the houting. As a result, the extinction of this species will impact the flow of nutrients throughout these ecosystems.
7) Inconnu (Stenodus leucichthys)
The inconnu, more commonly known as the sheefish, is a large Salmonid with an average length of around 24 inches (61 cm) and a maximum weight of approximately 88 lbs (40 kg). They have noticeably large bodies with small heads that sometimes give them an amusing appearance. Like the houting, the inconnu suffers from habitat degradation and the obstruction of migratory streams and spawning grounds. The loss of spawning habitat and fishing pressure particularly impacted this species. As a result, this species is considered extinct in the wild and only survives through intensive stocking efforts.
The inconnu is known for its aggressive temperament and fight on the line. Anglers looking for an exciting angling experience can expect to find this species stocked in the western United States bays, rivers, and streams. Large spinners and swimbaits work well for this species, and they are not picky about the type of bait, although baitfish found nearby are usually perfect options.
8) Great Lakes whitefish (Coregonus clupeaformis)
This whitefish has a rounded snout that protrudes past its lower jaw and possesses dark fin margins. Additionally, the body produces a slight hump behind the head in large adults. Otherwise, Great Lakes whitefish resemble other members of the Coregonus genus and may be difficult to distinguish outside of their native range.
During the breeding season, they migrate in the fall and winter to shallow areas of the lakes to spawn. Here, breeding adults wait until nightfall to deposit hundreds of thousands of eggs in the shoals. Juveniles predate upon zooplankton and small aquatic vertebrates. Due to their small mouths, adults maintain a diet consisting of small aquatic invertebrates and mollusks.
A large commercial fishery is sustained on lake whitefish. Additionally, they are popular species to icefish and fish for during warmer months.
9) Baikal whitefish (Coregonus migratorius)
Lake Baikal is the deepest and oldest lake in the world, with a maximum depth of 5,387 feet (1,642 meters). As an ancient lake, it harbors astounding levels of biodiversity, including its species of whitefish, which generally has a silvery coloration with blue hues along the body. On average, the Baikal whitefish is 19 inches (48 cm) long, making it a decent food fish for locals who refer to the delicious fish as “omul.” As a result, it is an important food source and is incorporated into many Russian soups and stews.
Baikal whitefish primarily consume bottom-dwelling invertebrates and large fish. During the breeding season, which occurs in October, adults will stop eating and migrate from the depths of Lake Baikal to the streams that feed into the lake in search of safe shallows to spawn in. Adults will leave their eggs scattered on the bottom of riverbeds and can produce between 8,000 and 30,000 eggs during each spawning event. Despite their high reproductive rate, rising threats like pollution and overfishing have resulted in dwindling numbers, and strict harvesting regulations have been imposed to prevent further declines.
10) Powan (Coregonus clupeoides)
Powans are valued as a recreational fish species in Scotland, attracting anglers who appreciate their feisty temparament. Powans are primarily found in deep, cold, and clear freshwater lakes, and their range is restricted to waters in Scotland. They prefer these lakes’ oligotrophic (low nutrient) waters and are particularly associated with large lochs in Scotland, such as Loch Lomond, Loch Eck, and Loch Tay. They are opportunistic predators that hunt zooplankton, insect larvae, and small invertebrates.
Powans usually spawn during winter or early spring, migrating to shallow lake areas where they release their eggs. The eggs are adhesive and attach to submerged vegetation or rocks. After hatching, the fry stay close to the shoreline, feeding on zooplankton until they grow larger and venture into deeper waters. Powan populations are classified as vulnerable by the IUCN. As a result, they are protected in the United Kingdom due to declining populations and habitat degradation. Pollution, habitat loss, and the introduction of non-native species have contributed to the decline of powan populations in some areas.
11) Pollan (Coregonus pollan)
The endangered pollan is restricted to specific waters in Ireland, often referred to as loughs, including Lough Mead, Lough Ernie, and Lough Ree. Their appearance is like other species of whitefish with a silver body and few other obvious distinguishing features. Thankfully, they have a restricted range that does not overlap with many other salmonids. Its spawning season lasts from October to December. The pollan’s diet includes crustaceans and other aquatic invertebrates.
Pollan populations have declined in recent decades due to various factors, including habitat degradation, overfishing, and the introduction of non-native species. Efforts are underway to protect and restore pollan populations to their native lakes. Pollan has historically been an important commercial and recreational fish species in Ireland. However, due to population declines, fishing regulations and conservation measures have been implemented to manage the species sustainably.
12) Broad whitefish (Coregonus nasus)
The broad whitefish’s range overlaps with several other species of whitefish, although this species is the widest physically by comparison. Broad whitefish are born in streams and float to the ocean to mature. Their mouth is angled downwards to enable them to pick small invertebrates off the ocean floor. Additionally, broad whitefish forage in freshwater and estuarine habitats, making them a versatile and important predator and prey item.
Spawning occurs in the fall and winter when adults migrate upstream to spawn over gravel beds. Unlike other salmonid species, like the sockeye salmon, broad whitefish can reproduce multiple times throughout their lives, allowing them to live for a long time. The maximum recorded age of a broad whitefish is 35 years. For species with specific spawning requirements, like whitefish, protecting spawning grounds and reducing blockages in migration pathways is imperative.
13) Vendace (Coregonus albula)
Although no populations of the vendace have been recorded in the United States in the last century, it was accidentally introduced in the 1880s from Europe. This Eurasian Salmonid is often stocked in German and Polish reservoirs. To distinguish it from other Salmonids, its lower jaw extends past its upper jaw. The vendace is also smaller on average than many other species of whitefish, with an average length of 4 – 8 inches (10 – 20 cm). Consequently, their diet almost exclusively consists of small aquatic and surface-dwelling invertebrates.
The vendace has a streamlined body shape with a silvery coloration. It has a small mouth and large eyes, adapted for feeding in dimly lit waters. The vendace typically spawns in the winter, from November to January, when water temperatures are low. They migrate to shallow, gravelly areas near the shorelines of lakes to lay their eggs. The eggs hatch within a few weeks, and the fry moves to deeper waters.
The vendace is considered a vulnerable species and the main threats to their population include habitat degradation, pollution, and competition with non-native fish species. Conservation efforts focus on protecting their habitats, managing fisheries sustainably, and monitoring their people.
14) Northern whitefish (Coregonus peled)
The northern whitefish is a freshwater whitefish native to the northern regions of Europe and Asia. They have a streamlined body with silvery scales, like other whitefish species. It has a slightly humped back, a pointed snout, and a deeply forked tail. The fish typically has a silvery-green or bluish coloration on the upper body, fading to a silvery-white shade on the sides and belly. There is very little information about this fish as a food fish although, since it is a Salmonid, it is likely prized for its filets.
Northern whitefish are found in freshwater environments, including lakes, reservoirs, and rivers. They inhabit cold waters and prefer well-oxygenated, deep areas, and often migrate to shallow waters for spawning. The diet of the northern whitefish primarily consists of small invertebrates, insects, and zooplankton. They feed by filtering these organisms from the water using specialized gill rakers.
The northern whitefish is a protected species.
Non-Salmonid Whitefish
1) Atlantic cod (Gadus morhua)
As common food fish for humans, cod filets are often seen in groceries stores, and the fish filets are used in a variety of processed fish products. The commercial harvest of Atlantic cod is a significant source of income for many New England states. The fish was once so abundant that English explorers named Cape Cod after it! Today, overfishing and overharvesting threaten cod populations, and the species is considered vulnerable by the IUCN.
Cod are easily distinguished from Salmonids by the presence of three dorsal fins. The size of an individual varies based on where it is found, with inshore individuals being much smaller than offshore individuals, averaging 27 – 34 inches (69 – 86 cm) and 40 – 42 inches (102 – 107 cm), respectively. They have large eyes that allow them to hunt for small fish and mollusks in the dark ocean depths. Despite their size, adult cod fall prey to sharks, marine mammals, and humans.
2) Haddock (Melanogrammus aeglefinus)
The haddock is easily identified as a cod relative by the presence of three dorsal fins. The first dorsal fin is dramatically pointed, and the fish is dark in color with a definitive spot behind its pectoral fin. Usually found at depths between 150 and 300 feet (46 to 91 m), this species is a cold-water deep-sea fish with an appetite for fish eggs, sea urchins, crustaceans, aquatic worms, and other fish. They are also an important food source for larger fish, seals, and sharks. The average haddock is around 12 inches (30 cm), but individuals can grow over 40 inches (102 cm).
In Europe, haddock filets are used in the iconic British fish and chips, and their filets are also sold fresh and frozen and are used in many processed foods meant for human and animal consumption. During the breeding season, which lasts from January to June, adult haddock congregate in groups over gravel beds to spawn. Each female can produce between 850,000 and 3 million eggs, with only a fraction of their offspring surviving to adulthood.
Haddocks are considered vulnerable by the IUCN.
3) Pollock (Gadus chalcogrammus)
Pollocks form large schools at extreme depths (330 and 985 feet or 101 to 300 meters) and are most abundant in the Bering Sea, where they support an extremely productive commercial fishery. Salmon bycatch, or the unintentional capture of salmon in nets designed to catch pollock, is a concern for the fishery as it reduces salmon populations during a life stage that is not sustainable to harvest. As a result, the pollock fishery uses scientific data collection and novel technology to manage salmon populations.
Alaskan pollock is one of the most valuable commercial fisheries in the United States. Its filets can be consumed in typical cooking or processed into imitation crab and fish sticks. When harvested sustainably, the Alaskan pollock is a healthy and sustainable protein source compared to poultry and livestock. Their short lifespans, high reproductive output, and careful and scientifically driven management keep populations at sustainable levels.
