There are 67 species of freshwater* fish found in Maine today. Most species found in the state are in the carp/minnow family (Cyprinidae). The next two most species-rich families are the trouts (Salmonidae), which are cold water species, and the bass/sunfishes (Centrarchidae), which are primarily warm-water species. Approximately 70% of Maine's fish species are native to the state.

18 different families of fish species are present in Maine. Click on a family listed below to get general information about the family and it's distribution in the state.

Information Sources:

Catfish: Family Ictaluridae

Brown bullhead (Ameiurus nebulosus). Image courtesy of MDIFW

Species present in Maine:

While this is the largest family of freshwater fishes endemic to North America, only one species is native to Maine – the brown bullhead (Ameiurus nebulosus). This bullhead is one of the most common species in Maine lakes, particularly larger systems at lower elevations. Although the brown bullhead is tolerant of degraded conditions, it also frequently occurs in lakes with good water quality. The other ictalurid species present in Maine is the non-native white catfish (A. catus). First recorded from Maine in the early 1980s, it has been recently collected from the Androscoggin, Cathance and Kennebec Rivers.

Cods: Family Gadidae

Cusk (Lota lota). Image courtesy of MDIFW

Species present in Maine:

The cusk is the only truly freshwater representative of this predominantly marine family. Although widespread in Maine, it is not common, occurring in about 8% of surveyed lakes. Most of these lakes are >100 acres. The cusk is also found in many of the larger rivers. Apparently, this species is particularly uncommon in the Downeast and northeast regions of the state.

Eels: Family Anguillidae

American eel (Anguilla rostrata). Image courtesy of MDIFW

Species present in Maine:

The American eel is the only catadromous fish in North America. This means that the fish travel down rivers to breed in the ocean, though they spend the majority of their life cycle in inland waters. They have been recorded from 32% of Maine ’s surveyed lakes, most of which are under 1000 ft elevation. Historically, the American eel is estimated to have compromised 25% of total fish biomass in coastal streams of the eastern U.S. Based on harvest and limited assessment data, populations have been in significant decline in the recent years. Over-harvest, barriers to migration, and habitat degradation are factors responsible for their decline.

Herrings: Family Clupeidae

Alewife (Alosa pseudoharengus). Image courtesy of MDIFW

Species present in Maine:

Herring populations in Maine are represented by Blueback herring and American shad, which both travel up from the ocean to spawn in rivers, Alewife, which spawn in lakes and slow-moving stream habitats, and Gizzard Shad, not native to Maine. Sea-run alewife, which migrate from the ocean to spawn in freshwater, have been recorded from 104 lakes. Landlocked populations occur in another 31 lakes (data as of 2004).

Members of the herring family have been the focus of current efforts aimed at restoring anadromous fish runs to Maine rivers. A major restoration program for American shad and alewife began in the Kennebec River in 1986, using trap and truck stocking and, more recently, improvements to fish passage at dams.

Concerns have been raised that restored alewife populations might compete with species such as smelt, salmonid or other sportfishes. It has also been suggested that alewives may have significant impacts on water quality. In general, there appears to be little conclusive evidence documenting the impacts of alewives on other components of freshwater ecosystems in Maine.

Killifish: Family Fundulidae

Banded killifish (Fundulus diaphanus).
Image courtesy of Harvard University Museum of Comparative Zoology

Species present in Maine:

The banded killifish is the only primarily freshwater killifish in the northeastern U.S. It is common in Maine, recorded from 365 lakes, generally at elevations <1000 ft. The mummichog is typically found in brackish water.

Lamprey: Family Petromyzontidae

Sea lamprey (Petromyzon marinus).
Image courtesy of Penobscot River Restoration Project

Species present in Maine:

The only lamprey known from Maine is the sea lamprey, a parasitic species that occurs in the mid-coast and Downeast regions of the state. Lampreys spawn in stream riffles and runs, although the species is difficult to collect during stream fish surveys. Adults feed in lakes and in the ocean. The species has been recorded from lakes larger than about 500 acres. Another lamprey species, the non-parasitic American brook lamprey (Lampetra appendix), occurs along the Atlantic slope to just south of Maine. To date, however, it has not been recorded from the state.

Minnows/Carp: Family Cyprinidae

Golden shiner (Notemigonus crysoleucas). Image courtesy of MDIFW

Species present in Maine:

About 60% of Maine’s minnow species are likely native to the state. Most of the species occurring in Maine are considered both lake and stream dwellers. Six species are relatively common and broadly distributed in Maine: the golden shiner, creek chub, common shiner, fallfish, northern redbelly dace and blacknose dace. Eight species are rare, all but one of which are non-natives. The remaining minnow species exhibit predominantly northern and western distributions in the state.

The common carp is currently restricted to the Kennebec River system. Its distribution extended upstream in this river following removal of the Edwards dam in the late 1990s; it is likely that future dam removals will result in further expansion in the range of this species in Maine.

Mudminnows: Family Umbridae

Central mudminnow (Umbra limi).
Image courtesy of Harvard University Museum of Comparative Zoology

Species present in Maine:

The central mudminnow – not a true minnow – was first recorded in Maine in 1999 from the Orono – Old Town area. Multiple year classes were observed in subsequent years. It probably represents a release from a local bait dealer. The U.S. Environmental Protection Agency's EMAP survey in the 1990s recorded this species from only one location in New England (Vermont).

Perch: Family Percidae

Yellow perch (Perca flavescens). Image courtesy of MDIFW

Species present in Maine

Two of the three species in this family are native to Maine. The yellow perch is very common and often very abundant, the swamp darter is very rare. Although native to the state, yellow perch has been introduced to many lakes. It is found in lakes of all sizes, but appears to be rarely present in small higher-elevation ponds. The swamp darter is the only representative in Maine of the darter group of fishes, a group that is species-rich in other regions of the U.S. Maine is at the extreme northern edge of this species’ range; it is one of two species listed as of Special Concern by MDIFW. The third percid in Maine is the walleye. Introduced illegally in the Belgrade lakes region in the early 1900s, it does not appear to have spread greatly and its current status is unclear.

Pike / Pickerel: Family Esocidae

Northern pike (Esox lucius). Image courtesy of MDIFW

Species present in Maine:

There are four pike/pickerel species in Maine, two of which are relatively recent introductions. The muskellunge is an “accidental” migrant to Maine waters, following its introduction to the St. John river basin by Canadian biologists in the 1970s. The first confirmed reproduction in Maine waters occurred in 1981 and the species is now well-established in the watershed. The northern pike was first observed in Maine in 1981 and is now well established in parts of the Androscoggin and, especially, Kennebec, drainages. Most recently, it has been recorded from Pushaw Lake in the Penobscot basin.

 this watershed. Northern pike is known to hybridize with chain pickerel in the Belgrade lakes, and likely also competes with this and other gamefish species. The chain pickerel is probably native only to the southwestern part of the state. It may have been the first northeast species to experience extensive movement by humans to other parts of the state, with reports that it was introduced into the Penobscot basin in the early 1800s. Today, the chain pickerel is the sixth most common species, in terms of number of lakes inhabited. It is found in lakes of all sizes, but rarely occurs at elevations >1000 ft. The redfin pickerel is rare in Maine, restricted to a few sites in the lower mid-coast region of the state.

Rainbow smelt: Family Osmeridae

Rainbow smelt (Osmerus mordax). Image courtesy of MDIFW

Species present in Maine:

The only species in this family, the rainbow smelt, is native to coastal drainages. Its current statewide distribution largely reflects stocking as forage for landlocked salmon. Smelt occur in all elevation zones and are uncommon in ponds of less than 10 acres. There are some concerns that smelt may negatively impact some native fish species but conclusive data from Maine are sparse. Illegal species introductions are likely impacting smelt populations in some lakes. Smelt are harvested commercially, likely at unsustainably high rates in some river systems. 

Salmon/Trouts: Family Salmonidae

Brook Trout (Salvelinus fontinalis). Image courtesy of MDIFW

Species present in Maine:

Brook trout is the most widely distributed fish species in Maine, occurring in 69% of surveyed lakes, and an estimated 22,250 miles of streams (MDIFW data). Maine possesses the most significant brook trout resource in the northeastern U.S., and is one of Maine’s most sought-after game fish. Brook trout occurs statewide, and in lakes of all sizes and elevations. Natural distribution of brook trout is limited by water temperature, so in warmer lakes populations are often maintained by stocking. Trout is usually a symbol of clean, cold waters and pristine habitat.

Two other charr (Salvelinus) species are found in Maine, lake trout and Arctic charr. Lake trout, also called togue, are found statewide, but predominantly in the western and northern regions. Lake trout are characteristic of larger, deep, less productive lakes. Maine is the only U.S. state with native populations of Arctic charr, which is one of two freshwater species listed as of Special Concern by the Maine Department of Inland Fisheries and Wildlife. It is the only freshwater fish that is considered endemic to the New England states. Arctic charr were extripated from the Rangeley Lakes in the early 1900’s following the introduction of landlocked salmon and smelt. Arctic charr are found in few lakes in Maine (20, half of which have been stocked), but their populations seem to be stable.

Landlocked salmon are distributed statewide, generally in lakes with greater than 100 acres of surface area, and in 600 miles of rivers. Although this salmon is a Maine-native species, virtually all current populations are the result of past and/or present stocking. Maine’s other Salmo species, brown trout, is an introduction from Europe, although it has been in Maine for about 100 years. It is found mostly in lower elevation areas in southern and Downeat regions of the state, where it provides an alternate game fish species in waters that tend to be too warm for brook trout.

Lake whitefish and round whitefish are two other Maine-native salmonids. They are both relatively uncommon. Lake whitefish populations have been declining in many lakes, probably as a result of competition by smelt.

The only Pacific salmon species present in Maine today is the Rainbow trout, which is present in 10 lakes and stocked in several rivers.

Sculpins: Family Cottidae

Slimy sculpin (Cottus cognatus).
Image courtesy of Harvard University Museum of Comparative Zoology

Species present in Maine:

The slimy sculpin is the only member of this family in Maine. While characteristic of riffle areas in cold streams, it also inhabits lakes – it has been recorded from about 5% of surveyed lakes (in all elevation zones), tending to favor larger systems with rocky substrates.

Seabasses: Family Moronidae

White perch (Morone americana). Image courtesy of MDIFW

Species present in Maine:

The white perch is native in Maine only to coastal regions and low gradient river segments with direct coastal access. The fact that this species now occurs in one quarter of all surveyed lakes, in all regions of the state except for northern Aroostook County and the western-most mountains, is testimony to the human-associated translocation of fish species. White perch can stunt in lakes when there is over-production. There is speculation that white perch may be associated with excessive phytoplankton production in some lakes, perhaps via cropping by fish of filter-feeding zooplankton populations. An ongoing study (2005-2006) is attempting to evaluate this hypothesis. The other Maine representative of this family is the striped bass which here is a coastal, estuarine and large-river species. Gulf of Maine populations are today much smaller than they were historically, when strong spawning runs occurred in virtually all rivers along the New England coast.

Sticklebacks: Family Gasterostidae

Ninespine stickleback (Pungitius pungitius). Image courtesy of MDIFW

Species present in Maine:

All four North American sticklebacks are present in Maine. Two species occur statewide and are relatively common: the threespine and ninespine sticklebacks, whereas the fourspine stickleback and brook stickleback are much rarer.

Sturgeons: Family Acipenseridae

Atlantic sturgeon (Acipenser oxyrhynchus).
Image courtesy of Penobscot River Restoration Project

Species present in Maine:

The shortnose sturgeon, a federally endangered species, is a large-river and coastal fish that occasionally enters open sea. The primary population in Maine is in the Kennebec basin, but it has recently (2006) been recorded in the Penobscot River. Although not listed as endangered, the Atlantic sturgeon has, like the shortnose sturgeon, become significantly depleted throughout much of its range.

Suckers: Family Catostomidae

Common sucker (Catostomus commersoni). Image courtesy of MDIFW

Species present in Maine:

The common sucker, also know as white sucker is the second most common fish species in Maine lakes, being more common at lower elevations and in larger systems. Its sister species, the longnose sucker, is much less common in Maine. This species is resticted largely to western and northern Maine and so it is rarely found at elevations <300 ft. It is not commonly found in smaller lakes and then only at higher elevations. The third member of this family, the creek chubsucker is primarily a stream species.

Sunfishes/Bass: Family Centrarchidae

Pumpkinseed sunfish (Lepomis gibbosus). Image courtesy of MDIFW

Species present in Maine:

Most Maine representatives of this family are not native to the state. The two species that are native, the pumpkinseed and redbreast sunfish, typically occur south of a diagonal extending from the Umbagog Lake region, in the south, to Madawaska, in the north. They are infrequently seen in the western-most regions of the state, or in lakes above 1200 ft. elevation. Redbreast sunfish is generally not present in smaller lakes (<50 acres), whereas the pumpkinseed is found in lakes of all size classes. Scientists consider the pumpkinseed to be the most widespread lake-dwelling fish species in the northeastern U.S.; it is the seventh most frequently recorded species in Maine lakes. The other two sunfish species, the green sunfish and bluegill, are recent introductions to Maine (via the Sebasticook River drainage; and not widespread at the current time).

Maine has two black bass species: the smallmouth and largemouth bass. The smallmouth occurs in about 30% more lakes than the largemouth. Bass were among the earliest introductions to the state – 1868 in the case of the smallmouth. Today, their ranges continue to increase in Maine as a result of illegal introductions to both lake and stream/river systems. Expansion of bass into the Rapid River/Richarson Lakes area is today a major concern. Pond-in-the-River (just west of Lower Richardson Lake), for example, has one of the highest, if not the highest, diversities of native minnows in the state. This large number of species is unlikely to persist in the event of the area being colonized by bass. Bass provide a good example of a significant dilemma in fisheries management – both species are valuable gamefish and are actively managed as such in many lakes and streams. However, their continued spread threatens other gamefish species, in addition to non-game species.

The black crappie is much less common than bass, but its distribution parallels that of largemouth bass in Maine. It was originally introduced in 1925, in Stoneham, Oxford County. The newest centrachid to be found in this region is the rock bass, recorded in 2002 from the Androscoggin River (in the New Hampshire section of the watershed).