Invasion HistoryFirst Non-native North American Tidal Record: 1839
First Non-native West Coast Tidal Record: 1933
First Non-native East/Gulf Coast Tidal Record: 1839
General Invasion History:
Goldfish (Carassius auratus) are native to China, Korea, and Eurasia from the Lena to the Amur Rivers; and possibly were introduced in ancient times to Japan, Hainan, and Taiwan (Courtenay et al. 1984). They have been released many times, deliberately and accidentally, from the beginning of importation and culture in North America. They have been collected in the wild in all US states except Alaska (Fuller et al. 1999), and on all continents except Antarctica (Lever 1996). Goldfish were brought to North America in the 1600s and were established in waters around New York and Boston by the 19th century (Storer 1839, cited by Hartel 2002; De Kay 1842). They were spread by the commercial pet trade. They were raised by the United States Fish Commission (USFC) in Washington and distributed to individuals in at least 37 states between 1878 and 1893 (Smiley 1884a; Bean 1893). Established populations are found in many rivers flowing past major cities (Courtenay et al. 1984). This fish has been introduced to 49 states, but establishment is uncertain in some southern states (Fuller et al. 1999). Many wild populations are sporadic, but others are well-established (Courtenay et al. 1984).
North American Invasion History:
Invasion History on the West Coast:
Goldfish have been widely distributed in western North America, but the only estuarine populations of which we are aware, are in the Columbia River and the San Francisco Estuary (Cohen and Carlton 1995; Sytsma et al. 2004; USGS Nonindigenous Aquatic Species Program 2018). Commercial rearing Goldfish in the West started in the late 19th century. Goldfish were distributed to private individuals in California by the USFC as early 1882-1884 to encourage fish-farming, but it is not known if any of these fish were released to the wild (Dill and Cordone 1997).
Columbia River- The first sighting of Goldfish in the wild was from a bridge over the Willamette River, in Portland, Oregon in 1933 (Lampman 1946). Goldfish were later found further down river in Kalama, WA and near the mouth of the river in Astoria, OR (Chapman 1942). Most recent records are from the Portland area (Farr and Ward 1993; Sytsma et al. 2004)
San Francisco Estuary- Goldfish were probably widely kept and reared in California in the 20th century, but the earliest record from the Sacramento-San Joaquin Delta is 1963. Most catches occurred in upstream portions of the Delta (Herbold and Moyle 1989, cited by Cohen and Carlton 1995; Brown and Michniuk 2007), but they were also caught in Suisun Marsh (Matern et al. 2002; Feyrer and Healey 2003). They appear to have declined in abundance in recent decades, comprising ~3% catches reported by Herbold and Moyle (1989), and less than 1% on later lists (Matern et al. 2002; Feyrer and Healey 2003; Brown and Michniuk 2007).
Invasion History on the East Coast:
Goldfish were introduced to eastern North America in the 1600s and established around major cities by the mid-19th century. They were established in the Charles River waters around Boston by 1839 (Storer 1839, cited by Hartel et al. 2002), the Connecticut River in Hartford by 1844 (Whitworth 1968), the Hudson River in New York (de Kay 1842), the Delaware River in Philadelphia and the Potomac River in Washington by 1876-1879 (Uhler and Lugger 1876; Cope 1879). In estuaries Goldfish are most common in tidal fresh waters, but have been collected at salinities as high as 17 PSU (Schwartz 1965). In the Hudson River, they are most common in the upper and middle estuary (Mills et al. 1997; Daniels et al. 2005), but with some occasionally stray into New York Harbor (Briggs and Waldman 2002). The population in the Hudson River went through great fluctuations – Goldfish were abundant until 1979-1980, then declined due to an epidemic of furunculosis, but dramatically recovered by 2002 (Daniels et al. 2005). In the Delaware estuary Goldfish range from Trenton, New Jersey (the head of tide) to the brackish mouth of the Chesapeake and Delaware Canal in Chesapeake City, Maryland (Horwitz 1986; Weisberg et al. 2005). In the mainstem of the Chesapeake Bay, Goldfish range from the Conowingo Dam on the Susquehanna River, at the head of the Bay to the brackish waters of the Rhode River (McKeown 1984; Rob Aguilar, personal communication 2012). On the Potomac, they similarly range from the head of tide to the brackish Wicomico River (Lippson et al. 1979; Killgore et al. 1989; Starnes et al 2011). In Virginia, the only self-sustaining population may be in the Potomac (Jenkins and Burkhead 1993).
Records for estuarine waters south of Chesapeake Bay are rare, possibly because of higher summer temperatures. Isolated captures have been reported from the lower Altamaha River, Georgia (2018), the St. John River in Florida (1974), Galveston Bay, Texas (1990), and the lower Rio Grande (Poss 1990; Edwards and Contrera Balderas 1991; USGS Nonindigenous Aquatic Species Program 2018).
The early history of the Goldfish's invasion of the Great Lakes is not well-documented. There were probably releases of pet fish before 1878, the first documented transfers to the region began with United States Fish Commission (USFC)'s distributions of Goldfish to private individuals probably to encourage fish-farming (Emery 1985; Mills et al. 1993). The first lake-specific USGS records for Goldfish are 1925 for Lake Erie, 1957 for Lake Michigan, and 1964 for Lake Ontario (USGS Nonindigenous Aquatic Species Program 2018). Goldfish are most abundant in Lake Erie, which is warmer and shallower (Emery 1985). The only Lake Superior record is from a pond draining into the deep, cold lake (USGS Nonindigenous Aquatic Species Program 2018).
Invasion History in Hawaii:
Goldfish were introduced to the Hawaiian Islands before 1900 and occur in reservoirs on all the main islands (Brock 1960; Maciolek 1984).
Invasion History Elsewhere in the World:
Goldfish have been introduced to at least 62 countries (Food and Agricultural Organization 2018). Documented introductions to Europe occurred in 1611 in Portugal and 1665 in England, and were widely introduced as pets in Western Europe in the 18th century. Introductions to South Africa, South America, and Australia occurred in the 19th century, but most of the established populations seem to have been in subtropical and temperate regions (Lever 1996). Many populations are probably in urban ponds and reservoirs (Lever 1996). We have not found records of Goldfish in the brackish European Baltic and Black Seas.
Goldfish (Carassius auratus) belong to Cyprinidae, the carp and minnow family. Fish of this family have a single dorsal fin, abdominal pelvic fins, a lateral line, and cycloid (circular) scales. They lack true spines in their fins, but a few, including Common Carp (Cyprinus carpio), and Goldfish, have secondary spine-like structures. They lack teeth in their mouths, but have 1-3 rows of pharyngeal teeth. Most fishes of this family have forked tails (Page and Burr 1991). Goldfish have a stout and robust body with an elevated back, and a short head, and a ventral mouth lacking barbels. There are 25-34 scales on the lateral line. The dorsal fin is long, with a stout, saw-toothed spine-like ray with 15-21 rays. The anal fin has six rays, the first ray is spine-like (Page and Burr 1991; Murdy et al. 1997; Moyle 2002; Schofield et al. 2005). Goldfish can reach a length of 410 mm, but are more typically 120-170 mm (Moyle 2002). One book calls Goldfish the 'poodle of the fish world', with morphology and color radically changed by centuries of human selection (Rohde et al. 1994). When released into a natural environment natural selection by predators rapidly reverts the population to the 'wild-type'. Wild Goldfish are usually gray-green above, with brassy sides and a white or yellow belly (Page and Burr 1991; Murdy et al. 1997; Moyle 2002).
The genus Carassius consists of five species native to Europe and Asia. Where their ranges overlap they hybridize with each other and the Common Carp (Cyprinus carpio) (Rylkova et al. 2013). Two of these carp, the Japanese Silver Carp (C. langsdorfii) and Prussian Carp (C. gibelio), have been introduced to western North America (Elgin et al. 2014; Halas et al. 2014). These carps and their hybrids can be confused with wild Goldfish, especially when young.
Potentially Misidentified Species
Carassius carassius (Crucian Carp), native to Eurasia, is a larger relative of the Goldfish, which has both deep-bodied and slender forms. It has been reportedly introduced to Chicago and Texas, but these reports are unconfirmed, and may refer to Goldfish (Schofield et al. 2005).
Carassius gibelio (Prussian Carp) is native to Eastern Europe and Asia, to Siberia and China. Its most distinctive feature is a much deeper body than Goldfish or Common Carp. A population was discovered in Alberta in 2006, and is rapidly expanding in the prairie region of Canada. This fish is regarded as highly invasive in Europe (Elgin et al. 2014; Docherty et al. 2017).
Carassius langsdorfii (Japanese Silver Crucian Carp) is native to Japan (Froese and Pauly 2018). It has been introduced to Europe, and has recently been genetically identified from British Columbia and California. These fish may have been mixed in with shipments of Koi (ornamental strains of Common Carp, (Halas et al. 2018).
Cyprinus carpio (Common Carp) is much larger than the Goldfish (to 1220 mm) and has two barbels, but young fish can be confused and hybridization is common (Page and Burr 1997; Halas et al. 2018).
Goldfish (Carassius auratus) is a small-to-medium sized freshwater fish. The two sexes are not easily distinguished, though females are usually larger than males. The growth rate and size of this fish is strongly influenced by food and environment, including crowding in ponds and aquaria. For example, differences in growth rates were observed between populations in the Sacramento and San Joaquin Rivers (Moyle 2002). Age at maturity in culture can be as early as 8 months, but in wild populations, it occurs at 2-4 years (Jones et al. 1978; Wang 1986; Moyle 2002). Males in California usually mature in their second year (Moyle 2002). Fish can mature at sizes as small as 79 mm (Jones et al. 1978), but probably larger in the wild. A sample of females from the Sacramento River ranged from 121 to 169 mm (Moyle 2002). Fecundity varies greatly with size, from 2,000-400,000 (Jones et al. 1978). In wild populations in California, the average fecundity was 14,000 eggs per female (Moyle 2002). Spawning occurs over aquatic vegetation or tree-roots, with a male courting a female. The male fertilizes the eggs as they are scattered. The eggs adhere to vegetation, and hatch in three to ten days at 15 to 2.5 C (Jones et al. 1978; Wang 1986). The yolk-sac larvae are 3-5 mm at hatching, and remain near the bottom. They swim more as they develop; juveniles start forming schools at about 10 mm Wang 1986).
Goldfish, as indicated by their wide native and introduced geographical ranges, and their tolerance of captivity, are tolerant of a wide range of environmental conditions. They can survive winters in ice-covered ponds and can tolerate temperatures as high as 41 C (Carlander 1969; Jones et al. 1978). They have been collected at salinities as high as 17 PSU, although fish in experiments survived only 11-9 days at 15 PSU (Schofield et al. 2006). Egg and larval development can take place at 16-29.5 C and 0-8 PSU (Jones et al. 1978). In estuaries, Goldfish are most abundant in tidal freshwater, and often move upstream for spawning (Wang 1986; Murdy et al. 1997). They are tolerant of hypoxic conditions, and stagnant, polluted water (Jones et al. 1978; Moyle 2002). Goldfish prefer still or slowly flowing water, with heavy growth of vegetation. They are omnivorous, feeding on algae, vascular plants, detritus, and small benthic invertebrates (Murdy et al. 1997; Moyle 2002). Goldfish are relatively small and slow moving fish and are therefore vulnerable to fish and bird predators.
plants, algae, invertebrates
|General Habitat||Fresh (nontidal) Marsh||None|
|General Habitat||Grass Bed||None|
|General Habitat||Nontidal Freshwater||None|
|General Habitat||Tidal Fresh Marsh||None|
|General Habitat||Unstructured Bottom||None|
|Salinity Range||Limnetic||0-0.5 PSU|
|Salinity Range||Oligohaline||0.5-5 PSU|
|Salinity Range||Mesohaline||5-18 PSU|
Tolerances and Life History Parameters
|Minimum Temperature (ºC)||0||Experimental- Carlander 1969; Jones et al. 1978|
|Maximum Temperature (ºC)||41||Experimental- Carlander 1969; Jones et al. 1978|
|Minimum Salinity (‰)||0||Field- Jones et al. 1978|
|Maximum Salinity (‰)||17||Field- Schwartz 1965. In experiments, "standard' goldfish purchased from dealers had a median survival time of 9 days after stepwise transfer to 15 ppt. A strain sold as a saltwater bait fish ('black salty') had a median survival time of 11 days at 15 ppt (Schofield et al. 2006)|
|Minimum pH||4.5||Szczerbowski, 2001, cited by Schofield et al. 2005|
|Maximum pH||10.5||Szczerbowski, 2001, cited by Schofield et al. 2005|
|Minimum Reproductive Temperature||16||Experimental- Jones et al. 1978|
|Maximum Reproductive Temperature||29.5||Experimental- Jones et al. 1978|
|Minimum Reproductive Salinity||0||Field- Jones et al. 1978|
|Maximum Reproductive Salinity||8||Experimental- Jones et al. 1978|
|Minimum Length (mm)||76||Size at maturity (Jones et al. 1978)|
|Maximum Length (mm)||400||Jones et al. 1978|
General ImpactsGoldfish (Carassius auratus) are economically important as pets and are bred for their beauty. They are also used for bait and as feeder-fish for carnivorous pets, and as a forage fish gamefishes. When goldfish are released, they can develop dense populations in predator-free environments, which can have negative impacts by destroying aquatic plants and increasing turbidity (Richardson et al. 1995). In Australia, Goldfish reportedly feed on the eggs and larvae of native species (Invasive Species Specialist Group 2018). However, the larger carps (Common Carp (Cyprinus carpio), and other Asian Carps) have much larger impacts because of their larger size and less vulnerability to predators. A related fish, the Prussian or Gibel Carp (C. gibelio), formerly considered a subspecies of C. auratus, is considered to have serious impacts in western Europe and in its newly invaded range in Alberta, Canada (Almqvist 2007; Ruppert et al. 2018).
Goldfish and Common Carp (Cyprinus carpio) have been significant as native hosts of several Asian parasites which have spread to native North American fishes and to fishes of other continents. The parasitic copepod Lernaea cyprinacea has been found on Chinook Salmon (Oncorhychus tshawytscha) in the Willamette River, Oregon (Uzman and Rayner 1958), and in the San Francisco estuary Delta, on four native species - Hardhead (Mylopharodon conocephalus), Sacramento Blackfish (Orthodon microlepidotus), Sacramento splittail (Pogonichthys macrolepidotus), and Sacramento Pike-Minnow (Ptylocheilus grandis), and a non-native White Catfish, Ameiurus catus (Hensley and Nahhas 1975). Lernaea cyprinacea was found on Channel Catfish (Ictalurus punctatus) in the South Carolina coastal zone (Lawler 1978). This ectoparasite is known from a wide variety of fish species around the world. The fish-louse Argulus japonicus is known mostly from Goldfish in North American waters, but it has been collected from Gizzard Shad (Dorosoma cepedianum) and Fathead Minnows (Pimephales promelas) (LaMarre and Cochran 1992). Both of these ectoparasites are known to adversely affect fishes in captivity, but the effect on wild populations is unknown (Shields and Tidd 1974; Hoffman 1977).
Regional Distribution Map
|Bioregion||Region Name||Year||Invasion Status||Population Status|
|M060||Hudson River/Raritan Bay||1842||Def||Estab|
|M040||Long Island Sound||1844||Def||Estab|
|S180||St. Johns River||0||Def||Unk|
|P090||San Francisco Bay||1963||Def||Estab|
|G330||Lower Laguna Madre||1985||Def||Unk|
|GL-I||Lakes Huron, Superior and Michigan||1878||Def||Estab|
|P023||_CDA_P023 (San Louis Rey-Escondido)||2008||Def||Unk|
ReferencesMabey, Abigail L.; Catford, Jane A.; Rius.; Foggo, Andrew ; Smale, Dan A. (2022) Herbivory and functional traits suggest that enemy release is not an important mechanism driving invasion success of brown seaweeds, Biological Invasions Published online: Published online
Almqvist, Gustaf (2007) <missing title>, Institute of Coastal Research, Swedish Board of Fisheries, Öregrund, Sweden. Pp. <missing location>
Bean, Tarleton H. (1893) The fishes of Pennsylvania, In: (Eds.) . , Harrisburg PA. Pp. <missing location>
Bean, Tarleton H. (1896) Report on the propagation and distribution of food-fishes, In: (Eds.) Report of the United States Commission of Fish and Fisheries for 1894. , Washington, D.C.. Pp. <missing location>
Brandler, Katherine G.; Carlton, James T. (2025) First report of marine debris as a species dispersal vector in the temperate Northwest Atlantic Ocean, Marine Pollution Bulletin 188(114631): Published online
Briggs, Philip T.; Waldman, John R. (2002) Annotated list of fishes reported from the marine waters of New York, Northeastern Naturalist 9(1): 47-80
Brock, Vernon E. (1960) The introduction of aquatic animals into Hawaiian waters, Internationale Revue der Gesamten Hydrobiologie 45(4): 463-480
Carmichael, John; Richardson, Brian; Roberts, Margaret; Jordan, Stephen J. (1992) <missing title>, CRBM-HI-92-2 Maryland Department of Natural Resources, Tidewater Administration, Chesapeake Research and Monitori, Annapolis, MD. Pp. <missing location>
Chapman, Wilbert M. (1942) Alien fishes in the waters of the Pacific Northwest, California Fish and Game 28: 9-15
Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>
2023 Seaweeds of Alaska. <missing description>
Cope, Edward Drinker (1879) The Fishes of Pennsylvania, In: (Eds.) Report of the State Commisioners of Fisheries. , Harrisburg. Pp. <missing location>
Courtenay, Walter R., Jr., Hensley, Dannie A., Taylor, Jeffrey N., McCann, James A. (1986) Distribution of exotic fishes in North America, In: Hocutt, Charles H., and Wiley, E. O.(Eds.) The Zoogeography of North American Freshwater Fishes. , New York. Pp. 675-698
Courtenay, Walter R., Jr.; Hensley, Dannie A.; Taylor, Jeffrey; McCann, James A. (1984) Distribution of exotic fishes in the continental United States., In: Courtenay, Walter R., and Stauffer, Jay R.(Eds.) Distribution, Biology, and Management of Exotic Fishes. , Baltimore, MD. Pp. <missing location>
Crivelli, A. J. (1995) Are fish introductions a threat to endemic freshwater fishes in the northern Mediterranean region?, Biological Conservation 72: 311-319
Crossman, E. J. (1984) Introduction of exotic fishes into Canada., In: Courtenay, W. R., Jr. and Stauffer, J. R., Jr.(Eds.) Distribution, Biology, and Management of Exotic Fishes. , Baltimore, MD. Pp. 78-101
Daniels, Robert A.; Limburg, Karin E.; Schmidt, Robert E; Strayer, David L.; Chambers, R. Christopher (2005) Changes in fish assemblages in the tidal Hudson river, New York., American Fisheries Society Symposium 45: 471-503
De Kay, James E. (1843) Mollusca, Vol. 5, Zoology of New-York., In: (Eds.) Zoology of New-York. , Albany. Pp. <missing location>
Dill, William A.; Cordone, Almo J. (1997) History and status of introduced fishes in California, 1871-1996, California Department of Fish and Game Fish Bulletin 178: 1-414
Edwards, R. J., Contreras-Balderas, S. (1991) Historical changes in the ichthyofauna of the lower Rio Grande (Rio Bravo Del Norte), Texas and Mexico., Southwestern Naturalist 36(2): 201-212
Edwards, Robert J.; Contreras-Balderas, Salvador (1991) Historical changes in the ichthyofauna of the lower Rio Grande (Rio Bravo del Norte), Texas and Mexico, Southwestern Naturalist 36(2): 201-212
Emery, Lee (1985) Review of fish species introduced into the Great Lakes, 1819-1974., Great Lakes Fisheries Commission 45: 1-31
Ernst, Carl H.; Wilgenbusch, James C.,; Morgan, Donald L.; Boucher, Timothy P.; Sommerfield, Mark (1995) Fishes of Fort Belvoir, Virginia, Maryland Naturalist 39(3-4): 1-60
Fairchild, G. Winfield, Horwitz, Richard J., Nieman, Douglas A., Boyer, Michael R., Knorr, Donald F. (1998) Spatial variation and historical change in fish communties of the Schuylkill River drainage, southeast Pennsylvania, American Midland Naturalist 138: 282-295
Farr, Ruth A., Ward, David L. (1992) Fishes of the lower Willamette River, near Portland, Oregon, Northwest Science 67(1): 16-22
Feyrer, Frederick; Healey, Michael P. (2003) Fish community structure and environmental correlates in the highly altered southern Sacramento-San Joaquin Delta., Environmental Biology of Fishes 66: 123-132
1998-2012 Database on Introductions of Aquatic Species. Web address http://www.fao.org/fishery/introsp/search/en
Fuller, Pam. L.; Nico, Leo; Williams, J. D. (1999) Nonindigenous fishes introduced into inland waters of the United States, American Fisheries Society, Bethesda MD. Pp. <missing location>
Hartel, Karsten E.; Halliwell, David B.; Launer, Alan E. (2002) Inland Fishes of Massachusetts, Massachusetts Audubon Society, Lincoln MA. Pp. 328 pp.
Hastings, Robert W.; Good, Ralph E. (1977) Population analysis of the fishes of a freshwater tidal tributary of the lower Delaware River, Bulletin of the New Jersey Academy of Science 22(2): 13-20
Hensley, Gary H., Nahhas, F.M. (1975) Parasites of fishes from the Sacramento-San Joaquin Delta, California., California Fish and Game 61(4): 201-208
Hoffman, Glenn L. (1977) Argulus, a Branchiuran parasite of freshwater fishes, United States Fish and Wildlife Service Fish Disease Leaflet 49: 1-9
Horwitz, Richard J. (1986) Fishes of the Delaware estuary in Pennsylvania., In: Majundar, S.K., Brenner, F. J., Rhoads, A. F.(Eds.) Endangered and Threatened Species Programs in Pennsylvania.. , Philadelphia. Pp. 177-201
Howarth, John N. (1961) Sampling for young of the year fishes with a 50-foot bag seine and surface trawl., In: Whitney, Richard R.(Eds.) The Susquehanna fishery study, 1957-1960.. , Solomons, Maryland. Pp. <missing location>
2006 <i>Eriocheir sinensis</i> (crustacean) Global Invasive Species Database.. http://issg.appfa.auckland.ac.nz/database/species/ecology.asp?si=38&fr=1&sts=
Jenkins, Robert E.; Burkhead, Noel M. (1993) Freshwater Fishes of Virginia, American Fisheries Society, Bethesda, MD. Pp. <missing location>
Jones, Philip W.; Martin, F. Douglas; Hardy, Jerry D., Jr. (1978) Development of fishes of the mid-Atlantic Bight. V. 1. Acipenseridae through Ictaluridae., In: (Eds.) . , Washington DC. Pp. <missing location>
Kilian, Jay V. and 6 authors (2012) An assessment of a bait industry and angler behavior as a vector of invasive species, Biological Invasions 14: published online
Kilian, Jay V. and 6 authors (2010) The status and distribution of Maryland crayfishes, Southeastern Naturalist 9(Special Issue 3): 11-32
Killgore, K. Jack; Morgan, Raymond P. II; Rybicki, Nancy B. (1989) Distribution and abundance of fishes associated with submersed aquatic plants in the Potomac River, North American Journal of Fisheries Management 9: 101-111
Kim, Jeongho; Ubagan, Michael; Kwon, Soyeon; Kim, l-Hoi; Shin, Sook (2022) Variation in genetics, morphology, and recruitment of the invasive barnacle Amphibalanus eburneus (Gould, 1841) in the southern Korean peninsula, PeerJ 10: Published online
Kraus, Richard T.; Jones, R. Christian (2012) Fish abundances in shoreline habitats and submerged aquatic vegetation in a tidal freshwater embayment of the Potomac River, Environmental Monitoring and Assessment 184: 3341-3357
LaMarre, Ellen; Cochran, Philip A. (1992) Lack of host species selection by the exotic parasitic crustacean, Argulus japonicus., Journal of Freshwater Ecology 7(1): 77-80
Lampman, Ben Hur (1946) Coming of the Pond Fishes, Binfords & Mort, Portland, OR. Pp. <missing location>
Lawler, Adrian R. (1978) An annotated checklist of the biota of the coastal zone of South Carolina, University of South Carolina Press, Columbia. Pp. 309-345
Lee, David S.; Gilbert, Carter R.; Hocutt, Charles H.; Jenkins, Robert E.; McAllister, Don E.; Stauffer, Jay R. (1980) Atlas of North American freshwater fishes, North Carolina State Museum of Natural History, Raleigh. Pp. <missing location>
Leidy, R. A. (2007) <missing title>, San Francisco Estuary Institute, Oakland. Pp. <missing location>
Lever, Christopher (1996) Naturalized fishes of the world, Academic Press, London, England. Pp. <missing location>
Lippson, Alice J.; Haire, Michael S.; Holland, A. Frederick; Jacobs, Fred; Jensen, Jorgen; Moran-Johnson, R. Lynn; Polgar, Tibor T.; Richkus, William (1979) Environmental atlas of the Potomac Estuary, Martin Marietta Corp., Baltimore, MD. Pp. <missing location>
Lippson, Alice J.; Moran, R. Lynn (1974) Manual for identification of early developmental stages of fishes of the Potomac River estuary., In: (Eds.) . , Baltimore MD. Pp. <missing location>
Loos, Jules J., Woolcott, William S., Foster, Neal R. (1972) An ecologist's guide to the minnows of the freshwater drainage systems of the Chesapeake Bay estuary, ASB Bulletin 19(3): 126-138
Maciolek, J. A. (1984) Exotic fishes in Hawaii and other islands of Oceania., In: Courtenay, W. R., Jr., and Stauffer, J. R., Jr.(Eds.) Distribution, Biology, and Management of Exotic Fishes. , Baltimore, MD. Pp. 131-161
Magalhaes, Andre´ L. B.; Jacobi, Claudia M. (2013) Asian aquarium fishes in a Neotropical biodiversity hotspot: impending establishment, spread and impacts, Biological Invasions published online: <missing location>
Martin, Mayo (1983) Goldfish farming, Aquaculture Magazine 9(4): 38-48
Matern, Scott A.; Moyle, Peter; Pierce, Leslie C. (2002) Native and alien fishes in a California estuarine marsh: twenty-one years of changing assemblages, Transactions of the American Fisheries Society 131: 797-816
Matern, Scott; Meng, Lesa; Pierce, Leslie C. (2001) Native and introduced larval fishes of Suisun Marsh, California: the effects of freshwater flow., Transactions of the American Fisheries Society 130: 750-765
McKeown, Paul E. (1984) Additions to ichthyofauna of the Susquehanna River with a checklist of fishes of the Susquehanna River drainage below Conowingo Dam, Proceedings of the Pennsylvania Academy of Science 58: 187-192
Mills, Edward L.; Leach, Joseph H.; Carlton, James T.; Secor, Carol L. (1993) Exotic species in the Great Lakes: a history of biotic crises and anthropogenic introductions., Journal of Great Lakes Research 19(1): 1-54
Mills, Edward L.; Scheuerell, Mark D.; Carlton, James T.; Strayer, David (1997) Biological invasions in the Hudson River: an inventory and historical analysis., New York State Museum Circular 57: 1-51
Moreno-Valcárcel, Raquel; Oliva-Paterna, Francisco J.; Bevilacqua, Stanislao; Terlizzi, Antonio; Fernández-Delgado, Carlos (2016) Long-term effects of tidal restriction on fish assemblages in east Atlantic coastal marshlands, Marine Ecology Progress Series 543: 209-222
Murdy, Edward O.; Birdsong, Ray S.; Musick, John A. (1997) Fishes of Chesapeake Bay, Smithsonian Institution Press, Washington, D.C.. Pp. 57-289
Page, Lawrence M.; Burr, Brooks M. (1991) Freshwater Fishes: North America North of Mexico, Houghton-Mifflin, Boston. Pp. <missing location>
1999 Nonindigenous species in the Gulf of Mexico. <missing description>
Raasch, Maynard S.; Altemus, Vaughn L., Sr. (1991) Delaware's freshwater and brackish water fishes, a popular account , Society of Natural History of Delaware, Wilmingotn, Delaware. Pp. <missing location>
Radcliffe, Lewis; Welsh, W. W. (1916) A list of the fishes of the Seneca Creek, Montgomery County, Maryland Region, Proceedings of the Biological Society of Washington 29: 39-45
Ramsay-Newton, Christine; Drouin, Annick; Hughes, A. Randall; Bracken, Matthew E. S. (2017) Species, community, and ecosystem-level responses following the invasion of the red alga Dasysiphonia japonica to the western North Atlantic Ocean, Biological Invasions 19: 537–547
Richardson, M. J.; Whoriskey, F. G.; Roy, L. H. (1995) Turbidity generation and biological impacts of an exotic fish, Carassius auratus, introduced into shallow seasonally anoxic ponds, Journal of Fish Biology 47: 576-585
Rohde, Fred C.; Arndt, Rudolf G.; Lindquist, David G.; Parnell, James F. (1994) Freshwater fishes of the Carolinas, Virginia, and Delaware, Universilty of North Carolina Press, Chapel Hill NC. Pp. <missing location>
Schofield, Pamela J.; Brown, Mary E; Fuller, Pam L. (2006) Salinity tolerance of goldfish Carassius auratus L., a non-native fish in the United States., Florida Scientist 69(4): 258-268
Schofield, Pamela J.; Williams, James D.; Nico,Leo G; Fuller, Pam; Thomas, Matthew R. (2005) Foreign nonindigenous carps and minnows (Cyprinidae) in the United States – A guide to their identification, distribution, and biology, USGS Scientific Investigations Report 2005-5041: 1-89 + Appendices
Schwartz, Frank J. (1963) The freshwater minnows of Maryland, Maryland Conservationist 40(2): 19-29
Schwartz, Frank J. (1965) Natural salinity tolerances of some freshwater fishes, Underwater Naturalist 2(2): 13-15
Serafy, J. E.; Harrell, R. M. (1993) Behavioral responses of fishes to increasing pH and dissolved oxygen: field and laboratory observations, Freshwater Biology 30: 53-61
Serafy, Joseph E.; Harrell, Reginal M.; Hurley, Linda M. (1994) Mechanical removal of Hydrilla in the Potomac River, Maryland: Local impacts on vegetation and associated fishes, Journal of Freshwater Ecology 9: 135-143
Shields, Robert J., Tidd, Wilbur M. (1968) Site selection on hosts by copepodids of Lernaea cyprinacea L. (Copepoda)., Crustacean 1: 88-94
Simon, Carol A.; van Niekerk, H. Helene; Burghardt, Ingo; ten Hove, Harry A.; Kupriyanova, Elena K. (2019) Not out of Africa: Spirobranchus kraussii (Baird, 1865) is not a global fouling and invasive serpulid of Indo-Pacific origin, Biological Invasions 14(3): 221–249.
Smiley, Charles W. (1884) A statistical review of the production and distribution to public waters of young fish, by the United States Fish Commission, from its organization, to the close of 1880., Report of the United States Commission on Fish and Fisheries for 1881 <missing volume>: <missing location>
Smith, Barry A. (1971) The fishes of four low-salinity tidal tributaries of the Delaware River estuary., In: (Eds.) An Ecological Study of the Delaware River in the Vicinity of Artificial Island. , Ithaca, N.Y.. Pp. <missing location>
Smith, Hugh M.; Bean, Barton A. (1898) List of fishes known to inhabit the waters of the District of Columbia and vicinity., Bulletin of the U. S. Fish Commission 18: 179-187
Starnes, Wayne C.; Odenkirk, John; Ashton, Matthew J. (2011) Update and analysis of fish occurrences in the lower Potomac River drainage in the vicinity of Plummers Island, Maryland—Contribution XXXI to the natural history of Plummers Island, Maryland, Proceedings of the Biological Society of Washington 124: 280-309
Sytsma, Mark D.; Cordell, Jeffrey R.; Chapman, John W.; Draheim, Robyn, C. (2004) <missing title>, Center for Lakes and Reservoirs, Portland State University, Portland OR. Pp. <missing location>
Tidd, Wilbur, M, (1934) Recent infestations of goldfish and carp by the 'anchor parasite,' Lernaea cyprinacea., Transactions of the American Fisheries Society 64: 176-180
Uhler, P. R.; Lugger, Otto (1876) <missing title>, State of Maryland, Fisheries Commission, Annapolis. Pp. <missing location>
2003-2022 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov
Uzmann, J. R.; H. J. Rayner (1958) Record of the parasitic copepod Lernaea cyprinacea L. in Oregon and Washington fishes., Journal of Parasitology 44(4): 452-453
Waldman, John R.; Lake, Thomas R.; Schmidt, Robert E. (2006) Biodiversity and zoogeography of the fishes of the Hudson River watershed and estuary, American Fisheries Society Symposium 51: 129-150.
Wang, Johnson, C. S.; Kenehahan, Ronnie (1979) Fishes of the Delaware estuaries - a guide to the early life histories, EA Associates, Towson MD. Pp. <missing location>
Warner, Kendall (2005) Smallmouth Bass Introductions in Maine, Fisheries 30(11): 20-26
Weisberg, Stephen; Himchak, Peter; Baum, Tom; Wilson, Harold T.; Allen, Russell (1996) Temporal trends in abundance of fish in the tidal Delaware River, Estuaries 19(3): 723-729
Whitworth, Walter R. (1968) Freshwater fishes of Connecticut, Bulletin, State Geological and Natural History Survey of Connecticut 101: 1-134
Whoriskey, F. G., Brown, K. (1994) Under-ice observations of behavior of selected native and exotic fishes of the St. Lawrence system, Zoo Biology 13: 545-555
Worth, S. G. (1895) A review of the history and results of the attempts to acclimatize fish and other water animals in the Pacific states, In: (Eds.) Report of the United States Commission of Fish and Fisheries for 1893. , Washington D.C.. Pp. 78-138
Young, Craig S.; Lee, Cheng-Shiuan; Sylvers, Laine H.; Venkatesan, Arjun K.; Gobler, Christopher J. (2022) The invasive red seaweed, Dasysiphonia japonica, forms harmful algal blooms: Mortality in early life stage fish and bivalves and identification of putative toxins, Harmful Algae 118(102294): Published online