Invasion History

First Non-native North American Tidal Record: 1874
First Non-native West Coast Tidal Record: 1874
First Non-native East/Gulf Coast Tidal Record: 1949

General Invasion History:

White Catfish (Ameiurus catus) are native to Atlantic and Gulf drainages from the Hudson River to the Apalachicola River, Florida. They were introduced to the Connecticut, Charles, and Kennebec rivers in New England, and to the Pensacola and drainages on the Gulf (Page and Burr 1991; USGS Nonindigenous Aquatic Species Program 2014). On the West Coast, White Catfish were introduced to the Sacramento River in 1874 (Smith 1896; Cohen and Carlton 1995; Dill and Cordone 1997) and to the Columbia River in 1932 (Lampman 1946). In 1938 they were introduced to Puerto Rico (established), and unsuccessfully to the Philippines (Lever 1996).

North American Invasion History:

Invasion History on the West Coast:

In 1874 Livingstone Stone from the US Fish Commission, brought 56 White Catfish (Ameiurus catus) from the Raritan River and planted them in the Sacramento River near Stockton, California. These fish survived and spawned, and by 1877 were stocked in 12 counties in the Sacramento-San Joaquin watershed and in southern California. In 1878-1979, 30,000 White Catfish were stocked in 22 counties (Smith 1895). By 1900, there was a major commercial fishery for White Catfish in the Sacramento Delta, which was curtailed in 1953 because of fears of overfishing, but this fish remained an important sport fish (Cohen and Carlton 1995). In a 1980s survey, White Catfish were the most abundant species in the Delta between 1980-1984, and were third in 1993-1999, but dropped to tenth in rank in 2001-2003 (Feyrer and Healy 2003; Brown and Michniuk 2007). In the Yolo Bypass of the Sacramento River, at the head of the Delta, they were the most abundant fish in 1999-2006, comprising 46% of the fish sampled (Sommer et al. 2014). They commonly occur downstream in brackish Suisun Bay at salinities up to 12 PSU (Matern et al. 2002; Moyle 2002).

White Catfish are apparently established, but rare, in the Columbia River and basin. The date of their introduction into the Columbia River basin is uncertain. Unidentified 'catfish' were introduced into Silver Lake on the Cowlitz River, and reached the Columbia River (Smith 1895). In 1930, some White Catfish from California were planted in Blue Lake, near Portland, Oregon, which is adjacent to the Columbia River. A specimen was caught in the Columbia River, near Portland in 1943 (Lampman 1946) and two were caught in lower Columbia Slough, Portland in 2008-2009 (Van Dyke et al. 2009).

Invasion History on the East Coast:

White Catfish are native to the unglaciated portion of the Atlantic and easternmost Gulf Coastal Plain, north to the Hudson River estuary, but were absent from the glaciated coastal drainages of New England. They have been introduced to the Connecticut River (1960, Whitworth et al. 1968; Marcy 1976), the Thames River (CT, 1973, Whitworth 1996); the Charles River (MA, 1910-1949, Hartel 2002), the Merrimack River (1910-1949, Hartel 2002); Kennebec River-Merrymeeting Bay (2001, USGS Nonindigenous Aquatic Species Program 2018) and the Penobscot River (1980, USGS Nonindigenous Aquatic Species Programs 2006). These introductions probably represent a mixture of official and informal stockings. On Florida's Gulf Coast, White Catfish are native to the Apalachicola drainage, but considered introduced to the Choctawhatchee and Pensacola Bay drainages (USGS Nonindigenous Aquatic Species Program 2018). A commercial fisherman reared White Catfish in a pen in Lake Erie starting in 1939. A number of these fish escaped but did not become established (Emery 1985).

Invasion History Elsewhere in the World:

White Catfish were introduced to Puerto Rico, possibly as early as 1938 in a shipment of Channel Catfish from Baltimore MD (Lever 1996). They are established in several inland reservoirs on the Island (USGS Nonindigenous Aquatic Species Program 2018). One albino fish, presumably a discarded ornamental fish, was caught in a pond in England in 2005, the first record of this species in Europe (Britton and Davies 2006).


White Catfish (Ameiurus catus) are freshwater fish but are common in brackish regions of estuaries. Bullhead Catfishes (Ictaluridae) have four pairs of barbels, no scales, an adipose fin, stout spines at the origins of the dorsal and pectoral fins, and abdominal pelvic fins. The tail fin of the White Catfish is moderately forked, with rounded lobes. The base of the anal fin is relatively short, and the fin is rounded with 22-25 rays. The rear edge of the pectoral spines has 11-15 moderate saw-like teeth. The dorsal fin is relatively short, with one spine and 5-7 soft rays. The head is broad and depressed. Adults can reach 620 mm but are more usually 300 to 330 mm. White Catfish are gray-blue-black above, and white to light-yellow below, with a dusky to black adipose fin. The chin barbels are white, while the other barbels are dusky (Page and Burr 1991; Jenkins and Burkhead 1993; Murdy et al. 1997; Moyle 2002).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Chordata
Subphylum:   Vertebrata
Superclass:   Osteichthyes
Class:   Actinopterygii
Subclass:   Neopterygii
Infraclass:   Teleostei
Superorder:   Ostariophysi
Order:   Siluriformes
Family:   Ictaluridae
Genus:   Ameiurus
Species:   catus


Ictalurus catus (, None)
Pimelodus catus (None, None)
Silurus catus (Linnaeus, 1758)

Potentially Misidentified Species

Ameiurus melas
Ameiurus melas (Black Bullhead) is native to the Mississippi-Great Lakes basin and has been introduced to the San Francisco estuary and the Columbia River. The tail is squared-off, the pectoral spine lacks saw-like teeth, and the chin barbels are dark (Page and Burr 1991).

Ameiurus natalis
Ameiurus natalis (Yellow Bullhead) is native to the Atlantic Slope and Mississippi-Great Lakes basin and has been introduced to the San Francisco estuary and the Columbia River. The tail is squared-off, the pectoral spine has saw-like teeth, and the chin barbels are white or yellow (Page and Burr 1991).

Ameiurus nebulosus
Ameiurus nebulosus (Brown Bullhead) is native to the Atlantic Slope and Mississippi-Great Lakes basin and has been introduced to the San Francisco estuary and the Columbia River and Fraser Rivers. The tail is squared-off, the pectoral spine has saw-like teeth, and the chin barbels are dark. The body has dark brown mottling (Page and Burr 1991).

Ictalurus furcatus
Ictalurus furcatus (Blue Catfish) are native to the Mississippi-Gulf Basin, and has been introduced, but is rare, in the San Francisco estuary. Adults are very large, and bluish gray in color, without dark mottling. The caudal fin is deeply forked, and the anal fin has a straight edge but is tapered posteriorly (Page and Burr 1991).

Ictalurus punctatus
Ictalurus punctatus (Channel Catfish) are native to the Mississippi-Gulf Basin, and the southeastern Coastal Plain, and has been introduced to the San Francisco estuary and the Columbia River. Adults are large, gray in color, without scattered dark spots. The caudal fin is deeply forked, and the anal fin has a curved edge (Page and Burr 1991).



White Catfish (Ameiurus catus) are freshwater fish that often occur in estuaries. Male and female catfish do not have obvious morphological differences. They mature in 1-2 years, at 152-211 mm (Jones et al. 1978). Spawning occurs at 21-30 C in nests built near sand or gravel banks (Jones et al. 1978). The nests are up to 0.9 m across and 0.45 m deep. Wang (1986) reported nests 'in hollowed tubes, large cans, crevices or cement or rocky jetties'. Females contain 1000-3500 eggs. During spawning, the male and female embrace in a head-to-tail fashion, with the males' tail curled around the female's head. The eggs are very adhesive and laid in small clusters. They are usually guarded by the male, but sometimes by both parents. They take 6-7 days to hatch at 24-29 C (Jones et al. 1978; Jenkins and Burkead 1994). Prolarvae remain in the nest until the yolk-sac is absorbed. When the yolk-sac is absorbed, fin-ray development is complete, and the fish are juveniles, starting at ~14 mm. Juveniles swim in dense schools in shallow water (Jones et al. 1978; Wang 1986).

White Catfish (Ameiurus catus) range from cold-temperate to subtropical climates and tolerate temperatures from near 0 C in ice-covered rivers in winter, to 31 C (Kendall and Schwartz 1968; Page and Burr 1991). Adults tolerate salinities up to 14 PSU in the laboratory and have been reported at 12 to 14.5 PSU in the field (Kendall and Schwartz 1968; Jones et al. 1978; Murdy et al. 1997). Their habitats include 'sluggish, mud-bottomed pools, open channels, and backwaters of small to large rivers’, and fresh to brackish portions of estuaries (Wang 1986; Page and Burr 1991). White catfish are omnivorous and eat aquatic plants, benthic invertebrates, and small fishes. In the San Francisco estuary, young fish (~40 mm long) feed on corophiid amphipods, mysids, and chironomid midge larvae. As they grow, they include larger invertebrates, carrion, and fishes, but still feed largely on invertebrates (Moyle 2002). Surprisingly, growth rates of White Catfish in the Delta are slow, compared to East Coast and California lake/river populations, possibly because of a dense population, or a lack of forage fish (Schafter et al. 1997). Predators include larger fish, birds, and humans.


Aquatic plants; benthic invertebrates, fishes


fishes, birds, humans

Trophic Status:




General HabitatNontidal FreshwaterNone
General HabitatFresh (nontidal) MarshNone
General HabitatGrass BedNone
General HabitatCoarse Woody DebrisNone
General HabitatSwampNone
General HabitatTidal Fresh MarshNone
General HabitatSalt-brackish marshNone
General HabitatUnstructured BottomNone
Salinity RangeLimnetic0-0.5 PSU
Salinity RangeOligohaline0.5-5 PSU
Salinity RangeMesohaline5-18 PSU
Tidal RangeSubtidalNone
Vertical HabitatNektonicNone

Tolerances and Life History Parameters

Minimum Temperature (ºC)4Occurs in ice-covered water, eg. Hudson River
Maximum Temperature (ºC)31Experimental, acclimated to 20 C (Jones et al. 1978)
Minimum Salinity (‰)0A freshwater species
Maximum Salinity (‰)14.5Field data (Schwartz 1965)
Minimum Reproductive Temperature21Field data (Jones et al. 1978)
Maximum Reproductive Temperature30Field data (Jenkins and Burkhead 1994)
Minimum Reproductive Salinity0A freshwater species
Minimum Length (mm)152 Mature at 152-211 mm (Jones et al. 1978)
Maximum Length (mm)610 Jones et al. 1978

General Impacts

White Catfish (Ameiurus catus), together with other catfishes, are an important fishery species in their native range and in the San Francisco Bay estuary (Menzel 1945; Dill and Cordone 1997). While they are an abundant generalized predator on invertebrates and small fishes, there are no specific impacts of their introduction.

Economic Impacts

Fisheries- By 1880, six years after the introduction of the White Catfish to the San Francisco estuary, a substantial fishery was established. Smith (1896) quotes the California fish commissioners' report: 'The produce of the few fish of this species, imported in 1874, now annually furnishes a large and valuable supply of fish food to people in the interior of the State. The value of all the fish of this species now caught annually and consumed as food would more than equal the annual appropriation made by the State and placed at the disposal of the fish commissioners. In 1953, the commercial fishery was ended, because of fear of overfishing (Cohen and Carlton 1995). White Catfish continue to be an important warmwater sport fish in California, though it may be overtaken by Channel Catfish (Ictalurus punctatus), which are larger, and easier to catch (Moyle 2002).

Regional Impacts

P090San Francisco BayEconomic ImpactFisheries
By 1877, White Catfish supported a significant commercial fishery in the San Francisco Bay estuary (Smith 1896). In 1953, the commercial fishery was ended, because of overfishing, but it remains an important sportfish (Cohen and Carlton 1995; Dill and Cordone 1997).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
GL-II Lake Erie 1939 Def Failed
P260 Columbia River 1930 Def Estab
M040 Long Island Sound 1960 Def Estab
N150 Merrimack River 1949 Def Estab
N170 Massachusetts Bay 1949 Def Estab
P090 San Francisco Bay 1874 Def Estab
M060 Hudson River/Raritan Bay 0 Native Estab
M090 Delaware Bay 0 Native Estab
M130 Chesapeake Bay 0 Native Estab
S010 Albemarle Sound 0 Native Estab
S020 Pamlico Sound 0 Native Estab
S030 Bogue Sound 0 Native Estab
S050 Cape Fear River 0 Native Estab
S060 Winyah Bay 0 Native Estab
S070 North/South Santee Rivers 0 Native Estab
S080 Charleston Harbor 0 Native Estab
S090 Stono/North Edisto Rivers 0 Native Estab
S110 Broad River 0 Native Estab
S100 St. Helena Sound 0 Native Estab
S120 Savannah River 0 Native Estab
S130 Ossabaw Sound 0 Native Estab
S140 St. Catherines/Sapelo Sounds 0 Native Estab
S150 Altamaha River 0 Native Estab
S160 St. Andrew/St. Simons Sounds 0 Native Estab
S170 St. Marys River/Cumberland Sound 0 Native Estab
S180 St. Johns River 0 Native Estab
S183 _CDA_S183 (Daytona-St. Augustine) 0 Native Estab
S190 Indian River 0 Native Estab
S196 _CDA_S196 (Cape Canaveral) 0 Native Estab
S200 Biscayne Bay 0 Native Estab
G010 Florida Bay 0 Native Estab
G020 South Ten Thousand Islands 0 Native Estab
G030 North Ten Thousand Islands 0 Native Estab
G045 _CDA_G045 (Big Cypress Swamp) 0 Native Estab
G050 Charlotte Harbor 0 Native Estab
G070 Tampa Bay 0 Native Estab
G074 _CDA_G074 (Crystal-Pithlachascotee) 0 Native Estab
G078 _CDA_G078 (Waccasassa) 0 Native Estab
G076 _CDA_G076 (Withlachoochee) 0 Native Estab
G080 Suwannee River 0 Native Estab
G086 _CDA_G086 (Econfina-Steinhatchee) 0 Native Estab
G090 Apalachee Bay 0 Native Estab
G100 Apalachicola Bay 0 Native Estab
G110 St. Andrew Bay 0 Native Estab
G130 Pensacola Bay 1954 Def Estab
G120 Choctawhatchee Bay 0 Native Estab
G150 Mobile Bay 1996 Def Estab
N090 Kennebec/Androscoggin River 2001 Def Estab
N050 Penobscot Bay 1980 Def Unk

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


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DOI: 10.1111/ddi.13666