(Cantor, 1841) (northern snakehead)

Habitat: Stagnant shallow ponds, swamps and slow streams with mud or vegetated substrate, with temperatures ranging from 0 to >30^oC.
Life History: It reaches sexual maturity in 2 to 3 years at approximately 30-35 cm (12-14 inches) in length. Maximum size exceeds 85 cm (33 inches). Females release 1,300 to 15,000 eggs per spawn, which can occur 1 to 5 times per year. The floating eggs take 28 hours to hatch at 31^oC, 45 hours at 25^oC and much longer at cooler temperatures. Larvae remain in a nest guarded by their parents until yolk absorption is complete at approximately 8 mm in length. At approximately 18 mm the young begin feeding on small crustaceans and fish larvae. The northern snakehead has been reported to be an obligate air breather, which means that it can live in oxygen-depleted waters by gulping air at the water’s surface and survive several days out of water if kept moist.
Native Range: Eastern Asia; introduced to western Asia and eastern Europe during the 20^th century.
Nonindigenous Range: Formerly established in a pond in Crofton, Maryland.  Collected from Newton Pond, Shrewsbury, Massachusetts.
Impacts: These predatory fishes compete with native species for food and habitat. Juveniles eat zooplankton, insect larvae, small crustaceans, and the fry of other fish.  As adults they feed mostly on other fishes, with the remainder of their diet comprised of crustaceans, frogs, small reptiles, and some times small birds and mammals.
Comments: There is no evidence that juveniles or adult snakeheads escaped from the Crofton ponds. The northern snakehead has a wider latitudinal range and temperature tolerance than other snakehead species. It also seems to be adaptable to a wide range of aquatic environments, as evidenced by the spread of reproducing, introduced populations in Asia and Japan.  The presence of juveniles in the Crofton pond, evidence of reproduction there, demonstrates the significant potential that the northern snakehead would invade ponds, lakes and rivers in Maryland.  Rotenone can be used to eradicate northern snakeheads from lakes and ponds, however this chemical treatment will kill non-target fish species. Rotenone should be applied to the pond or lake with both surface spray application and injected underwater over the entire pond sufficient to achieve a dosage of at least 3 parts per million.

  (Lacepède, 1802) (blotched snakehead)

Habitat: Shallow, vegetated freshwater bodies; especially ditches, lakes, ponds and streams. Although blotched snakeheads are native to the tropics, they can survive for seven days out of water in 7^oC temperatures.
Life History: Where introduced in Japan, spawning occurs in early summer. Eggs are laid in an open, circular nest in vegetation then eggs float to the surface where they are guarded by parents (Okada, 1960).
Native Range: China south of the Yangtze basin and northern Vietnam.
Nonidigenous Range: Collected from a bridge over the Charles River in Boston, Massachusetts in late July 2002. 
Impacts: This predatory fish can impact native fauna; it feeds on crustaceans, large insects, frogs and fishes.
Comments: The species is available in at least one ethnic market in Boston.

  (Hamilton, 1822) (bullseye snakehead)

Habitat: Deep clear lakes and rivers with rocky or sandy substrate.
Life History: Spawning apparently occurs once to twice during warmer times of the year and brood size varies tremendously, from 350 to over 3600 young.   Parents guard the nest containing pale red-yellow eggs (2mm in diameter) and they guard the young until they reach 10 cm in length. 
Native Range: Pakistan, India, Sri Lanka, Bangladesh, southern Nepal and Southern China, Myanmar, Thailand, Laos, and Cambodia.
Nonindigenous Range: Collected from Baltimore Inner Harbor, Maryland.
Impacts: This predatory species has the potential impact native fish and crustaceans through predation if it ever became established.
Comments: The species is available in some live fish markets and obtainable, but rare, in the aquarium trade.

  (= C. micropeltis) (Cuvier, 1831) (giant snakehead)

Habitat: Lakes, reservoirs, canals, and rivers; most commonly deep, standing or slow flowing water.
Life History: Nest in a circular area, which the parents clear of vegetation.  Eggs rise and drift in the water column where they are guarded by parents. C. micropeltes ferociously guard their eggs, even attacking humans who approach the nest.
Native Range: Tropical Asia. Southeast Asia including India, Burma, Thailand, Laos, Malay Peninsula, Sumatra, Borneo, Java, Banka, and Billiton. 
Nonindigenous Range: Collected from the Rocky Gorge Reservoir on the Patuxent River (Maryland) in 2000; and three additional specimens from Maryland in 2002, but the specific localities were not disclosed. In the 1970s specimens were collected below the Springvale Dam on the Mousam River, York County and from the Saco River (Maine). Identification was never confirmed for the Saco River specimens.  Also collected from Pomps Pond, Andover (Massachusetts); as well as an unspecified pond and Johnston Pond, Coventry (Rhode Island).  The two Rhode Island records may reflect duplicate reports of a single collection.
Impacts: In its native habitat, this aggressive predator is destructive to other fishes, killing all kinds and sizes in excess of actual needs. Anglers and swimmers have been attacked by this species in its native range.
Comments: Juveniles are sold in the aquarium trade.

  (Agassiz, 1831) (oscar)

Habitat: Freshwater canals and ponds.
Life History: Where introduced in Florida, eggs are laid in June to October at 28 to 33^oC and are incubated by both parents. Young are also guarded by parents.
Native Range: South America including the Orinoco and Amazon basins; also French Guiana, and the northern part of Paraguay drainage, Parana basin.
Nonindigenous Range: Collected from island waters near Martha’s Vineyard and Nantucket (Massachusetts) and from an unspecified location in Massachusetts. Also collected from an unspecified location in Pennsylvania; a pond in northern Rhode Island; the Millstone River near its confluence with the Raritan River, New Jersey; and a Virginia Beach, Virginia area pond.
Impacts: Oscars are considered potential competitors with native centrarchids (sunfishes) for food and spawning areas.
Comments: Oscars are common in the aquarium trade.  Future research may determine that some oscars in the aquarium trade, as well as those collected in U.S. waters, are not A. ocellatus but another member of the genus. To confound the issue, artificial breeding has produced several color variants.

  (Steindachner, 1864) (blue tilapia)

Habitat: Subtropical fresh and brackish waters, 8 to 30^oC, including lakes ponds, and rivers.
Life History: Able to reproduce in fresh or brackish waters with multiple spawnings in one season. Nest in colonies when water temperature exceeds 22^oC; male builds nest and female incubates eggs in her mouth.
Native Range: Tropical and subtropical Africa and Middle East. Native range includes Senegal, Niger, and many smaller drainages and lakes in Africa and Middle East.
Nonindigenous Range: Once established in warm water effluents of a power plant on the Susquehanna River (Pennsylvania), after escaping from Pennsylvania Power and Light's Brunner Island Aquaculture Facility sometime after October 1982 . Populations in the vicinity of Brunner Island were eradicated in February 1986, when condenser cooling water was temporarily released at lethal, lower temperatures; however O. aureus may still survive farther downstream.  Before the eradication, tilapia were collected 78 km downstream from the Brunner Island site where warm water effluents are not influential.
Impacts: The blue tilapia is considered a competitor with native species for spawning areas, food, and space. In certain streams where O. aureus are abundant, most vegetation and nearly all native fishes are reportedly lost.  Also implicated as the cause for unionid mussel declines in two Texas water bodies, Tradinghouse Creek and Fairfield reservoirs.
Comments: Not able to withstand temperatures lower than 6-7^o C and will not feed below 16-17^oC.

  (Hubrecht, 1881) (zebra tilapia)

Habitat: Freshwater lakes and ponds; typically tropical.
Life History: Male-female pairs cooperatively excavate a depression or pit in the sediment until they reach a solid substrate.
Native Range: Western Africa; lower reaches of coastal rivers from Guinea-Bissau (Geba and Corubal Rivers) to west Liberia (St. John River).
Nonindigenous Range: A single large fish, identified by two independent experts, was collected from the Rappahannock River near Fredericksburg, Virginia in July 2000. This is the first report of this species in the country.
Impacts: Unknown.  Due to temperature constraints, it is unlikely this tropical species would establish in the Mid-Atlantic region.

  (Mitchill, 1814) (blueback herring)

Habitat: Anadromous; living in marine systems and spawning in deep, swift freshwater with hard substrate.
Life History: Migrate to spawning grounds in the spring.  In Connecticut, blueback herring spawn in 14 – 27^oC temperatures.  Young travel to the sea at about one month of age.
Native Range: Atlantic Coast from Cape Breton, Nova Scotia, to the St. Johns River, Florida. Ascends coastal rivers during spawning season.
Nonindigenous Range: Collected from Oneida Lake, the Oswego River in Minetto, and Lake Ontario (New York); and Lake Champlain (New York-Vermont). Stocked in several inland reservoirs including Smith Mountain Lake, Occoquan Reservoir, Kerr Reservoir, Lake Anna, Lake Brittle, and Lake Chesdin (Virginia); stocked in unspecified locations in Pennsylvania.
Impacts: Unknown. Established in New York, North Carolina, Vermont, and Virginia.

  (Günther, 1867) (threadfin shad)

Habitat: Lakes, ponds, rivers, reservoirs and estuaries.  Does not endure cold water (7 – 14^oC).
Life History: Spawning occurs often before one year of age over vegetation or logs in open water at 21^oC.
Native Range: The Ohio River (Indiana and Illinois) and the Mississippi River, (southern Illinois) south through the Mississippi River basin to the Gulf; Atlantic Slope drainages of Florida; Gulf drainages from south central Florida to northern Guatemala.
Nonindigenous Range: Collected from an unspecified location in Pennsylvania; established in the Potomac River (Maryland-Virginia-West Virginia); established in numerous drainages in Virginia; possibly established in the lower Kanawha and Ohio drainages of West Virginia. Also, stocked, but failed or extirpated in Coursey Pond (Delaware) and numerous locations in West Virginia.
Impacts: Populations in several West Virginia lakes extirpated by cold weather but established in other areas. Concern exists regarding possible impacts on other fish species with planktonic larvae, such as minnows and suckers, and on young centrarchids. Threadfin may compete with young centrarchids for food and have apparently destroyed kokanee fishing in some areas.
Comments: Some evidence indicates that this species is not native, but introduced, east of the Mississippi River as a forage fish in the early 1900s. There are no published records of the species east of the Mississippi River prior to the 1940s and a range expansion after 1940 may have resulted from a combination of natural range extension and human introduction.

  (Valenciennes, 1844) (grass carp)

Habitat: Rivers, large streams, ponds, and reservoirs with salinity up to 10 ppt, oxygen concentrations as low as 0.0005 ppt, and temperatures ranging from 0 to 35^oC. Require running water (rivers) in order to spawn. Will not reproduced in lakes.
Life History: Spawns during the warmer, rainy months in China.
Native Range: Eastern Asia from the Amur River of eastern Russia and China south to West River of southern China.
Nonindigenous Range: Throughout the northeastern United States except Maine, Rhode Island and Vermont.
Impacts: Effects of a grass carp introduction on a water body apparently depend on the stocking rate, macrophyte abundance, and community structure of the ecosystem.  Negative effects reported in the literature include inter-specific competition for food with invertebrates (e.g., crayfish) and other fishes, significant changes in the composition of macrophyte, phytoplankton, and invertebrate communities, interference with the reproduction of other fishes, and decreases in refugia for other fishes. Grass carp are often used to control selected aquatic weeds, but often consume non- target plant species. Secondarily, grass carp cause an increase in phytoplankton populations.  Grass carp may carry parasites and diseases potentially transmissible to native fishes such as the Asian tapeworm (Bothriocephalus opsarichthydis).
Comments: Both authorized and unauthorized stockings of grass carp have taken place for biological control of vegetation. Triploids are considered to be sterile and incapable of reproduction. However, some researchers find fertility to be low, not negated, in triploids. Triploid grass carp are indistinguishable in external morphology from normal (fertile) diploids. Thus, ensuring that grass carp being stocked are all triploid requires tissue sampling. Texas now bans grass carp for fear they will remove too much vegetation and thus destroy fish and wildlife habitat.  As of 1994, the states of Alaska, Oregon, Montana, North Dakota, Minnesota, Wisconsin, Michigan, Massachusetts, Vermont, Maine, Maryland, and Rhode Island prohibit grass carp, diploid and triploid, in their state.

  Linnaeus, 1758 (common carp)

Habitat: Lakes, streams, and ponds of any substrate or water clarity.
Life History: Spawns in spring and early summer when water reaches 17^oC by congregating in groups among vegetated shallows.
Native Range: Eurasia.
Nonindigenous Range: Recorded from all states except Alaska; and believed to be established in all northeastern and Mid-Atlanticstates except Maine.
Impacts: Regarded as a pest fish because of its widespread abundance and its tendency to destroy vegetation and increase water turbidity by dislodging plants and rooting around in the substrate. Causes deterioration of habitat for species requiring vegetation and clean water. Common carp are potential predators of native fish eggs.
Comments: More than 20,000 common carp were killed by a bacterial disease over a short period of time in the Merrimack River in the late 1970s.  Because common carp have a higher salinity tolerance than most freshwater fishes, they may spread from one coastal stream to another through fresh or nearly fresh coastal waters in the Gulf area during periods of heavy rainfall and run-off, periods when salinities are greatly reduced.

  (Richardson, 1845) (bighead carp)

Habitat: Filter feeder that prefers large river habitats.
Life History: Typically spawns at water temperatures of 18 - 25.5^oC in areas with rapid current or mixing water. Averages between 660,000 and 872,000 eggs per female per year.
Native Range: Southern and central China.
Nonindigenous Range: Collected from the Ohio River (West Virginia); and Sandusky Bay, Lake Erie (Ontario).
Impacts: Unknown. Planktivorous food habits and large size suggest these carp have the potential to deplete zooplankton populations.
Comments: Used in many parts of the world as a food fish and sometimes introduced in combination with silver carp into sewage lagoons and aquaculture ponds. In the United States, frequently stocked into catfish culture ponds. Scientists debate whether bighead carp actually do improve water quality in culture ponds.

  Rafinesque, 1818 (emerald shiner)

Habitat: Large lakes and open rivers, usually in large schools.
Life History: Spawns in spring to early summer over a wide range of temperatures.  Larvae emerge from eggs after 24 - 32 hours. Adults reach up to 4 inches (10.1 cm) and typically live only 3 years. Feeds on terrestrial insects during the summer and caddis worms, mayfly naiads, and amphipods in winter.
Native Range: St. Lawrence drainage, Quebec; Hudson River drainage, New York to Mackenzie River drainage (Arctic basin), Northwest Territories, and south through Great Lakes and Mississippi River basins to Gulf; Gulf Slope drainages from Mobile Bay, Alabama, to Galveston Bay, Texas.
Nonindigenous Range: Established at several unspecified locations in central and southern Maine; in the Jennings Randolph Reservoir (Maryland); and possibly native but perhaps introduced into the Kanawha drainage above the falls (West Virginia). Collected, and perhaps nonindigenous, in Lebanon and Erieville reservoirs (Susquehanna River drainage in New York) and from several large unspecified impoundments in Massachusetts. Some scientists list the emerald shiner as introduced into the Housatonic and Connecticut drainages, probably in the Massachusetts portion of these waters. 
Impacts: Unknown.
Comments: The Massachusetts specimens have never been examined by specialists, but this species is sold in bait stores in that state. Dramatic increases in abundance of this sight-feeding minnow in the Missouri River (part of its native range) may be the result of decreases in turbidity and other factors relating to the construction of upstream reservoirs.

  (Clinton, 1824) (spottail shiner)

Habitat: Predominantly large sluggish rivers and lakes, freshwater to brackish water (10.7 ppt salinity); also in streams.
Life History: Spawns in spring to early summer in various habitats; lake spawning occurs over sandy shoals.  Feeds on crustaceans, filamentous algae, and insects.
Native Range: Atlantic and Gulf Slope drainages from St. Lawrence River, Quebec to Altamaha and upper Chattahoochee River, Georgia; Hudson Bay, Great Lakes, and Mississippi River basins from Ontario to Mackenzie River drainage (Arctic basin), Northwest Territories and Alberta, and south to northern Ohio, southern Illinois, and northeastern Montana.
Nonindigenous Range: Established, or presumably established, in Maine, New Hampshire, New York, Pennsylvania, Virginia, and West Virginia. Established in the lower Kennebec River (Maine); the Connecticut and Merrimack rivers (New Hampshire) (where it may be introduced rather than native); the Allegheny Reservoir (New York-Pennsylvania border); the New River drainage (Virginia); and above the Kanawha falls (West Virginia).
Impacts: Unknown.

  Rafinesque, 1820 (fathead minnow)

Habitat: Wide range of habitats including ponds and flowing streams; tolerates high temperatures, high turbidity, and low oxygen; and schools near the bottom or in Mid-depths.
Life History:  Able to spawn during second year and over an extended spawning season, which commences during spring at water temperatures around 60^o F (15.6^oC).  Eggs are laid under floating objects in still water and guarded by the male. Feeds on algae and aquatic insect larvae.
Native Range: Widespread in North America from Quebec to Northern Territories, and south to Alabama, Texas, and New Mexico.
Nonindigenous Range: Established in all of the major and most of the coastal drainages in Connecticut; the Potomac and upper Chesapeake drainages (Maryland); the Housatonic River drainage, the Concord system, the Connecticut River drainage, and a pond in Amherst, Massachusetts; Susquehanna and Delaware river drainages in Pennsylvania; and Atlantic Slope and Ohio River basin drainages in West Virginia. Collected from the Youghiogheny River system, Maryland, the Lower Connecticut River drainage, Massachusetts; the Penobscot and (possibly) Kennebec river drainages in Maine; the Androscoggin River system in New Hampshire; various drainages in Virginia; and Mill Creek in Delaware.
Impacts: Unknown.
Comments: Popularity as a baitfish and the ease with which it is propagated have led to widespread introductions both within and outside the native range. Because the species has been so widely introduced, its natural range is somewhat obscure.

  (Pallas, 1776) (bitterling)

Habitat: Small lakes and slow-moving back waters with soft bottoms.
Life History: Can reach 110 mm.  Breeds in Spring; Rhodeus requires freshwater bivalves as spawning sites; eggs are deposited, fertilized, and hatch in live mussels.
Native Range: Europe from the Seine and other rivers of France eastward to Asia Minor, and northern China (there is a very wide geographical gap in the northern part of the Asian continent separating the ranges of the two subspecies).
Nonindigenous Range: The first records of this species (as Rhodeus amarus) were from the Sawmill River, a tributary of the Hudson River, at Tarrytown, Westchester County, New York in the early 1920s. Although it reportedly disappeared from this locality shortly after 1925, additional specimens were taken in subsequent years, with the last collection made in 1951. Two specimens were taken from the Bronx River at Bronxville, Westchester County, New York, in 1933; subsequent collections indicated the species was established in a localized reach of the river.
Impacts: Unknown.
Comments: Laboratory evidence has shown that this European fish will use certain U.S. native mussels (Anadonta cataracta and Unio complanatus). The reported recent decline in population of bitterling in the Bronx River apparently has resulted from a declining freshwater mussel population brought about by water pollution.

  (Linnaeus, 1758) (rudd)

Habitat: Still or slow moving freshwater.
Life History: Reaches 200-250 mm total length (TL) and 400 mm standard length (SL) in native range. Eggs laid in submerged aquatic vegetation nearshore.
Native Range: Western Europe to the Caspian Sea and Aral Sea basins.
Nonindigenous Range: Established in Lake Cobboseecontee in Kennebec County, (Maine); Copake Lake and downstream from Robinson Lake dam, Oneida Lake, Ostego Lake, north of Cheviot Landing (Hudson River), Ringneck Marsh, and Schroon Lake (New York); Burr Pond in Rutland County (Vermont); and Lake Anna (Virginia). Reported in Connecticut (specific location not disclosed); the Charles River, Cambridge and Benton Lake, Otis (Massachusetts); Lake Winola, west of Scranton (Pennsylvania); Lake Champlain (Vermont); Burke Lake, Gardy’s Mill Pond, and Lake Whitehurst (=Little Creek Reservoir) (Virginia); and the New River (West Virginia). Also recorded from numerous locations in New York such as: Central Park Lake, New York City; Cascadilla Creek near Ithaca in the Great Lakes basin in the early 1950s; Lake Ontario, Lake Erie; and the St. Lawrence River. Reportedly extirpated from a lake in Hudson County Park, Jersey City, New Jersey. 
Impacts: Largely unknown. In a laboratory setting, rudd readily hybridize with native golden shiner (Notemigonus crysoleucas), a primary forage species of many native game fishes. Thus, rudd introduced to open waters may hybridize with golden shiner, with unknown consequences to native populations of golden shiner. The potential exists for rudd to compete with native fishes that also feed on invertebrates.   Rudd can shift its diet to plants, unlike most native fishes. Because rudd are fairly hardy, the fish will fare better than many native fishes in waters that are eutrophic or polluted.
Comments: The recent and rapid spread of the species is a result of its use as a baitfish for white bass. Many states now outlaw the use of rudd as live bait, apparently slowing its spread.

  (Linnaeus, 1758) (tench)

Habitat: Lakes and backwaters of rivers; able to withstand hypoxic conditions.
Life History: Large numbers of eggs are laid amidst submergent aquatic vegetation during summer months; approximately 275,000 eggs are produced per pound of female’s body weight.  Males exhibit a thickened second pelvic ray when mature.
Native Range: Most of Europe, including the British Isles, and parts of western Asia.
Nonindigenous Range: In 2002, collected from Lake Champlain (Vermont). Established in the Housatonic drainage (Connecticut); as well as in undisclosed localities in New York; and Maryland. Also stocked, but not established in various locations in Delaware, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Virginia, and West Virginia.
Impacts: Unknown, though as early as the 1940s reported to be an abundant nuisance in Maryland. May compete with sport fish for food; aquatic insect larvae and molluscs.
Comments: Imported into North America from Germany by the U.S. Fish Commission in 1877 apparently for use as a food and sport fish. Although most tench introductions were the result of intentional stockings, some introductions were the result of escape from holding facilities.

  (Rafinesque, 1818) (flathead catfish)

Habitat: Large to medium rivers usually in deep holes; young commonly found in riffles of large rivers.
Life History: Becomes sexually mature at 3 - 4 years and lives to 20 years.  Feeds on fish and crustaceans.
Native Range: Lower Great Lakes and Mississippi River basins from western Pennsylvania to White-Little Missouri River system (North Dakota) and south to Louisiana; Gulf Slope from Mobile Bay drainage (Georgia and Alabama) to Mexico.
Nonindigenous Range: Apparently expanding its range along the east coast and currently established the Lower Delaware drainage (Blue Marsh Reservoir and Springton Reservoir), and the Schuylkill River drainage (Pennsylvania); as well as Occoquan Reservoir and middle Roanoke drainage (Virginia). Collected from Smith Mountain Reservoir, the upper James River (Botetourt County), and the lower James River near Surry (Virginia).
Comments: The flathead catfish is native to the Mississippi, Ohio, and the western Gulf drainages.  It has been introduced both legally and illegally for sport fishing. They prey heavily on sunfish (Lepomis spp.), common carp (Cyprinus carpio), and bullheads (Ameiurus spp.). Young-of-the-year feed on darters (Etheostoma spp.). Clupeids, Catostomids, Ictalurids (including other flatheads), Centrarchids, and crayfish are also consumed. The flathead catfish became the dominant predator in the Cape Fear drainage, North Carolina, within 15 years of the introduction. The state of Georgia is now trying to control them in the Altamaha River, and has taken an enormous amount of flathead biomass out of the river.

  (Gmelin, 1789) (white perch)

Habitat: Brackish water or coastal freshwater bodies.
Life History: Anadromous or remaining in freshwater; adults spawn in shallows during the spring in water temperatures of 11 -15^oC. Not all eggs are released at one time and total number of eggs for a spawning season range from 20,000 to 300,000.  
Native Range: Atlantic Slope drainages from St. Lawrence-Lake Ontario drainage (Quebec) south to Pee Dee River (South Carolina). Populations in Lake Ontario drainage probably became established following construction of the Erie Canal.
Nonindigenous Range: Established in all five Great Lakes and their surrounding states, as well as in Kentucky, Massachusetts, Missouri, Nebraska, New Hampshire, and Vermont. Nonnative and established in Lake Champlain (Vermont and New York); the Great Lakes drainage (New York); Lake Erie and Allegheny Reservoir (Pennsylvania); and inland waters (localities not specified) of Massachusetts and New Hampshire. Collected from Smith Mountain Reservoir and Kerr Reservoir (Virginia); and the upper Potomac drainage (West Virginia).
Impacts: White perch prey on eggs of walleye (Stizostedion vitreum vitreum), white bass (Morone chrysops), eggs of its own species, and possibly eggs of other species. Apparently, fish eggs are an important component of the diet of white perch in the spring months. White perch also feed heavily on minnows (Notropis spp).
Comments: The first report of white perch in the Great Lakes drainage was from Cross Lake, central New York, in 1950. The species evidently accessed the lake via the Erie Barge Canal during the warm weather in the 1930s and 1950s. White perch were stocked in West Virginia in the early 1900s.

  (Rafinesque, 1820) (white bass)

Habitat: Clear lakes and reservoirs and adjoining river systems.
Life History: Spawning on shoals and in streams during the spring, this potamodromus species (ie. migratory within freshwater) produces 61,700 to 994,000 eggs.
Native Range: St. Lawrence-Great Lakes, Hudson Bay (Red River), and Mississippi River basins from Quebec to Manitoba and south to Louisiana; Gulf Slope drainages from Mississippi River (Louisiana) to Rio Grande (Texas) and New Mexico.  Native to western New York and western Pennsylvania.
Nonindigenous Range: Established locally in New Jersey (specific locality not reported), southern Pennsylvania, Virginia, and West Virginia. Collected in Delaware, where the species is known from a single record in 1888 and, presumably is extirpated. Attempts to establish the species in the Youghiogheny River, Maryland and Pennsylvania failed.
Impacts: Unknown.

  hybrid (wiper)

Native Range: Artificial hybrid occurring naturally only in Arkansas.
Nonindigenous Range: Established in the upper Susquehanna and Chenango drainages (New York); and the Potomac drainage (Virginia). Collected from the Brandywine-Christina and Broadkill-Smyrna drainages (Delaware).  Stocked in Lake Hopatcong (New Jersey); non-specified localities in New York; Nockamixon Lake (Pennsylvania); Leesville Lake and the Rappahonnock River (Virginia); and the Ohio River and its tributaries, and the Kanawha River (West Virginia).
Impacts: Backcrossing, mating with the parental native species, has been observed and may cause loss of genetic integrity of the parent species or even the loss of a native species, subspecies, or of a unique population.
Comments: The wiper (palmetto, whiterock, Cherokee) is the result of crossing a female striped bass with a male white bass, and was first cultured in 1965. The sunshine bass, first produced in 1973, is the result of the reverse cross. Most introductions are of the wiper hybrid; however, a few sites have been stocked with sunshine bass, including some lakes in Florida. These hybrids reportedly grow faster, survive better, and are caught more readily than their parent species the striped bass. However, they don't become as large as striped bass.

  (Mitchill, 1814) (rainbow smelt)

Habitat: Inshore coastal waters and midwaters of large lakes typically in schools; freshwater of 43^o – 56^oF is optimal.
Life History: Reproductive maturity is reached after two years; spawning is during night hours in the spring. Eggs (from 8,000 to 70,000 in number) sink and attach to gravel substrate by way of a short stalk.
Native Range: Atlantic drainages from Lake Melville (Newfoundland) to Delaware River (Pennsylvania) and west through Great Lakes; Arctic and Pacific drainages from Bathurst Inlet (Northwest Territories) to Vancouver Island (British Columbia). Also, Pacific drainages of Asia.
Nonindigenous Range: Established in the Shetucket and Lower Connecticut drainages (Connecticut), the Upper Susquehanna-Lack drainage (Pennsylvania), Lake Erie, Lake Champlain, coastal Maine, numerous localities in New York, and unspecified localities in Massachusetts. Additional collections in several localities in Pennsylvania; and failed stocking attempts in Massachusetts, Maryland, and Virginia.
Impacts: In the Great Lakes, rainbow smelt compete with lake herring (Coregonus artedii) for food and may be responsible for the decline of whitefish (Coregonus spp.). Atlantic salmon reportedly experienced increased growth following the introduction of smelt as a forage species in a lake in Maine.
Comments: This species is eaten by humans and used as bait for salmonids and walleye.

  (Cope, 1868) (banded darter)

Habitat: Small to medium rivers or riffles along shores of large rivers (Lee et al., 1980).
Life History: Spawning occurs June to July; adults reach 45-62 mm SL (Lee et al., 1980).
Native Range: Lake Michigan and Mississippi River basins from southwestern New York to Minnesota, and south to northern Georgia, northern Alabama, and southern Arkansas. Absent from Former Mississippi Embayment; Wabash River drainage of Ohio, Indiana, and Illinois; and streams of southern Illinois, southern Iowa, and northern Missouri.
Nonindigenous Range: Established in the Susquehanna River and its associated drainages (Pennsylvania & New York). Collected from the Lower Susquehanna drainage in Maryland.
Impacts: Introduced banded darters are hybridizing with native tessellated darters (E. olmstedi) in the Susquehanna River, Pennsylvania.

  Linnaeus, 1758 (sea lamprey)

Habitat: Generally marine but ascends freshwater rivers to spawn.
Life History: Spawn in spring and producing as many as 236,000 eggs when stream temperatures reach 11^o C (52^oC).
Native Range: Atlantic Coast from Labrador to Gulf of Mexico (Florida); landlocked in Great Lakes and several New York lakes. Also along Atlantic coast of Europe and Mediterranean Sea.
Nonindigenous Range: Established in Lake Champlain (Vermont and New York), the Finger Lakes (New York), and throughout the Great Lakes.
Impacts: Attack and parasitic feeding on other fishes by adult lampreys often results in death of the prey, either directly from the loss of fluids and tissues or indirectly from secondary infection of the wound.
Comments: Some scientists suggest sea lampreys found in Lake Ontario and its tributaries, the Finger Lakes, and Lake Champlain represent relict populations from the last Pleistocene glaciation. Those contending that it is not native believe that this species, unknown in Lake Ontario prior to the 1830s, had most likely entered the inland lake from Atlantic coastal drainages via the Erie Canal (e.g., Emery 1985). Beginning in the late 1950s, sea lampreys began to be successfully controlled by use of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM), a chemical agent that kills larval lampreys in their stream habitats. Continued use of TFM is apparently required to keep sea lamprey populations under control. TFM is sometimes harmful to other fish (e.g., walleye), as well as to the larvae of non-parasitic lamprey species. The demise of lake trout led to development of the splake, a hybrid between lake trout and brook trout. It was hoped that the hybrid would better avoid lampreys and mature faster, hence spawn at least once before becoming parasitized. As of 1991, it was estimated that the U.S. and Canada were spending $8 million per year on lamprey control and another $12 million per year on lake trout restoration. 

  (Walbaum, 1792) (rainbow trout)

Habitat: Creeks, rivers, lakes, ponds and reservoirs.
Life History: In the northeastern and Mid-Atlantic U.S., spawns in streams during spring and early summer. Fry hatch in Mid-summer. 
Native Range: Pacific Slope from Kuskokwim River (Alaska) to (at least) Rio Santa Domingo, Baja California; upper Mackenzie River drainage (Arctic basin), Alberta and British Columbia; endorheic basins of southern Oregon.
Nonindigenous Range: Established in numerous drainages in Connecticut (exact locations not reported); Massachusetts, Maryland, Maine, New Jersey, New York, Virginia, Vermont, and West Virginia, as well as Lake Erie.  Collected or stocked at additional sites in Maine, Maryland, New Hampshire, New Jersey, Pennsylvania, Virginia, and West Virginia.
Impacts: The rainbow trout hybridizes with other, more rare trout species, thereby affecting their genetic integrity.

  (Walbaum, 1792) (chinook salmon)

Habitat: Predominantly marine but migrating into large rivers to spawn.  In the less common freshwater populations, such as in New Hampshire, breeding occurs along shore or in adjoining rivers.
Life History: Spawns at 2 to 9 years of age, with spawning season varying among chinook salmon populations or stocks. Number of eggs varies widely, as well.  Average number of eggs is 8517 in Alaska and 2500 in freshwaters of New Hampshire. Eggs are orange-red and 6 - 7 mm in diameter.
Native Range: Arctic and Pacific drainages from Point Hope (Alaska) to Ventura River (California); occasionally strays south to San Diego (California). Also in northeastern Asia.
Nonindigenous Range: Established in Lake Erie; Lake Ontario; the Salmon-Sandy drainage (New York); and the Raritan and Delaware drainages (New Jersey). Collected from unspecified areas in Connecticut and Maine; the North River (Massachusetts); throughout Maryland; western New Jersey; and the lower James and lower Potomac rivers (Virginia). Stocked locally, but failed to establish in Delaware, Maine, Massachusetts, New Hampshire, and Pennsylvania.  Also reportedly extirpated in oligotrophic lakes of New Hampshire, and the Delaware River (Pennsylvania).
Impacts: Competes with native lake trout (Salvelinus namaycush). Chinook salmon are predatory fish and as such may impact populations of smaller fish. The species had totally eliminated rainbow smelt (Osmerus mordax) in two small New Hampshire lakes where the salmon was stocked to control the smelt.

  Linneaus, 1758 (brown trout)

Habitat: Freshwater streams and lakes.
Life History: Spawns in late fall and early winter often after an upstream migration. Eggs are laid in a depression, known as a redd, in the stream bottom made by the female. Hatching occurs in the spring.
Native Range: Europe, northern Africa, and western Asia.
Nonindigenous Range: Established throughout much of New Hampshire, New York, Pennsylvania, and western Virginia; the Connecticut River (Connecticut); an undisclosed site in Delaware; Cape Cod and cold water streams of Berkshire Valley and the central uplands (Massachusetts); the Potomac and Upper Chesapeake drainages (Maryland); southern and coastal, lakes and streams in Maine; Cooper River and other undisclosed localities (New Jersey); and Lake Champlain and Groton Pond (Vermont).
Impacts: Brown trout have been implicated in reducing native fish populations (especially other salmonids) through predation, displacement, and food competition.
Comments: Can tolerate higher temperatures (up to 70^o F) and more silt than other salmonids, but is not as valued as a food fish when compared to the brook trout (Salvelinus fontinalis) and rainbow trout (Oncorhynchus mykiss).