FWS Focus

Overview

Characteristics
Overview

Silver carp (Hypophthalmichthys molitrix) are one of four nonnative fish species belonging to a group commonly referred to as “invasive carp”. Native to eastern Asia, silver carp were introduced to the United States during the 1970’s and 1980’s to private fish farms and wastewater treatment facilities as a biological control agent to reduce algae growth and improve water quality conditions of the ponds. By the 1990’s, they escaped into the Mississippi River during high water flooding events and spread rapidly throughout the Mississippi River drainage. These planktivorous fish have a narrow, deep body that is laterally compressed and have a large, toothless mouth with an upturned lower jaw that lacks barbels. Their body is covered in very small silver scales except for their head which is scaleless. Their eyes are situated far forward on the head, sit below the mouth, and project downwards. They have a keel which extends along the belly from their anal fin to the base of their gills. They can grow upwards of 3 ft in length and commonly reach 20 pounds with the largest individuals reaching upwards of 80 to 90 pounds. Silver carp are popularly known for acrobatically jumping out of the water when startled by the noise of boat motors, becoming potential hazards for recreational boaters (Asian Carp Canada 2021; Kolar et al. 2021; Nico et al. 2021; TMWC 2021).Currently in the U.S., they can be found in the Mississippi, Missouri, Ohio, Tennessee, and Cumberland Rivers and many of their tributaries. They have been reported in states such as Alabama, Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Minnesota, Mississippi, Missouri, Nebraska, Nevada, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas, and Wisconsin. Since 2007, they have been listed as injurious wildlife under the Lacey Act which adds all forms of live silver carp (Hypophthalmichthys molitrix), gametes, viable eggs, and hybrids to the list of injurious fish, mollusks, and crustaceans. The best available information indicates that this action is necessary to protect the interests of human beings, and wildlife and wildlife resources, from the purposeful or accidental introduction, and subsequent establishment, of silver carp and largescale silver carp populations in ecosystems of the United States. Live silver carp and largescale silver carp, gametes, viable eggs, and hybrids can be imported only by permit for scientific, medical, educational, or zoological purposes, or without a permit by Federal agencies solely for their own use; permits will also be required for the interstate transportation of live silver or largescale silver carp, gametes, viable eggs, or hybrids.

Asian Carp Canada. 2021. Silver carp. Ontario, Canada: Invasive Species Centre. Available: https://www.asiancarp.ca/asian-carps/silver-carp/ (October 2021).

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Nico, L.G., Fuller, P., and Li, J. 2021. Hypophthalmichthys molitrix (Valenciennes in Cuvier and Valenciennes, 1844). Gainesville, FL: U.S. Geological Survey, Nonindigenous Aquatic Species Database. Available:  https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=549 (October 2021).

[TMWC] Tip of the Mitt Watershed Council. 2021. How to identify Asian carp. Petoskey, MI: Tip of Mitt Watershed Council. Available: https://www.watershedcouncil.org/how-to-identify-asian-carp.html (October 2021).

Scientific Name

Hypophthalmichthys molitrix
Common Name
silver carp
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Physical Characteristics

Young black carp feed primarily on zooplankton and later on insect larvae and detritus. Adult black carp feed primarily on mollusks, such as mussels and snails, using their pharyngeal (throat) teeth to crush the shells. They also eat freshwater shrimp, crawfish, and insects

Size & Shape

The silver carp is a narrow, deep-bodied fish that is laterally compressed that as a large, toothless mouth with upturned lower jaw and lacks barbels. Their body is covered in very small silver scales except for their head which is scaleless. Their eyes are situated far forward on the head, sit below the mouth, and project downwards. They can be distinguished from bighead carp due to their keel which extends along the belly from their anal fin to the base of their gills whereas bighead carp have keels that only extend from their anal fin to pelvic fin, and their pectoral fins only extend to the base of their pelvic fin as opposed to beyond the pelvic fin in bigheads. They can grow upwards of 3 ft in length.

Asian Carp Canada. 2021. Silver carp. Ontario, Canada: Invasive Species Centre. Available: https://www.asiancarp.ca/asian-carps/silver-carp/ (October 2021).

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Nico, L.G., Fuller, P., and Li, J. 2021. Hypophthalmichthys molitrix (Valenciennes in Cuvier and Valenciennes, 1844). Gainesville, FL: U.S. Geological Survey, Nonindigenous Aquatic Species Database. Available:  https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=549 (October 2021).

[TMWC] Tip of the Mitt Watershed Council. 2021. How to identify Asian carp. Petoskey, MI: Tip of Mitt Watershed Council. Available: https://www.watershedcouncil.org/how-to-identify-asian-carp.html (October 2021).

Weight

Individuals commonly reach 20 pounds with the largest individuals reaching upwards of 80 to 90 pounds.

Asian Carp Canada. 2021. Silver carp. Ontario, Canada: Invasive Species Centre. Available: https://www.asiancarp.ca/asian-carps/silver-carp/ (October 2021).

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Color & Pattern

Their bodies are very silvery in color, especially when young, and later develop a greenish hue on their back to silver on the belly as they age. Their scales are small, and troutlike while their head and opercles are scaleless (Kolar et al. 2005; Nico et al. 2021; TMWC 2021).

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Nico, L.G., Fuller, P., and Li, J. 2021. Hypophthalmichthys molitrix (Valenciennes in Cuvier and Valenciennes, 1844). Gainesville, FL: U.S. Geological Survey, Nonindigenous Aquatic Species Database. Available:  https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=549 (October 2021).

[TMWC] Tip of the Mitt Watershed Council. 2021. How to identify Asian carp. Petoskey, MI: Tip of Mitt Watershed Council. Available: https://www.watershedcouncil.org/how-to-identify-asian-carp.html (October 2021).

Characteristic category

Behavior

Characteristics
Behavior

They are a schooling species and can be found grouped in large numbers. They are popularly known for acrobatically jumping out of the water (up to 9 ft or 3+ meters) as motor boats drive by due to being startled from the sound of boat motors.

Asian Carp Canada. 2021. Silver carp. Ontario, Canada: Invasive Species Centre. Available: https://www.asiancarp.ca/asian-carps/silver-carp/ (October 2021).

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128

Characteristic category

Food

Characteristics
Food

Silver carp are planktivores and filter feed on both phytoplankton and zooplankton (Kolar et al. 2005; Pendleton et al 2017; Sass et al. 2014).

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Pendleton RM, Schwinghamer C, Solomon LE, Casper AF. 2017. Competition among river planktivores: are native planktivores still fewer and skinnier in response to the silver carp invasion? Environmental Biology of Fishes 100:1213-1222.

Sass GG, Hinz C, Erickson AC, McClelland NN, McClelland MA, Epifanio JM. 2014. Invasive bighead and silver carp effects on zooplankton communities in the Illinois River, Illinois, USA. Journal of Great Lakes Research 40:911-921. 

Characteristic category

Habitat

Characteristics
Habitat

Silver carp occur in a variety of freshwater habitats including large rivers and warmwater ponds, lakes, and backwaters that receive flooding or are otherwise connected to large rivers. They also have been introduced widely to ponds, lakes, reservoirs, and canals where they have been reported to thrive well, but probably can’t reproduce without access to an appropriate riverine habitat. They prefer open areas and eutrophic zones of standing or slow-flowing waters and occupy the upper and middle layers of the water column. In the U.S., they prefer slow flowing water habitats such as contiguous backwaters, tributary streams, main channel borders, side channel borders, behind wing dikes, and slow-flowing portions of large rivers where it may pool while avoiding main channel type habitat. Silver carp are quite tolerant of broad water temperatures from 4 °C to 40 °C. Silver carp are known to feed at water temperatures of 10 to 19 °C; in the Missouri River, silver carp sometimes had full guts at temperatures lower than 4 °C. Although they’re a freshwater species, they can also live in slightly brackish water and tolerate salinities ranging from 1.5 to 12%.

Calkins HA, Tripp SJ, Garvey JE. 2012. Linking silver carp habitat selection to flow and phytoplankton in the Mississippi River. Biological Invasions 14:949-958.

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Lake
River or Stream
Characteristic category

Lifecycle

Characteristics
Lifespan

Commonly reach 3-5 years of age, but can live upwards of 15 to 20 years.

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Nico, L.G., Fuller, P., and Li, J. 2021. Hypophthalmichthys molitrix (Valenciennes in Cuvier and Valenciennes, 1844). Gainesville, FL: U.S. Geological Survey, Nonindigenous Aquatic Species Database. Available:  https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=549 (October 2021).

Williamson CJ, Garvey JE. 2005. Growth, fecundity, and diets of newly established silver carp in the Middle Mississippi River. Transactions of the American Fisheries Society 134:1423-1430.

Lifecycle

In its native range, silver carp mature by age 3 and live for as many as 8 years, whereas individuals in introduced areas, such as the U.S., appear to be reproducing by age 2 and only reach 5 years of age. Adults breed in rivers or tributaries over shallow rapids with gravel or sand bottom, in upper water layer or even at surface during floods when the water level rises. Juveniles and adults form large schools during spawning season. Mature individuals undertake long distance upriver migration at start of a rapid flood and water-level increase. After spawning, adults migrate to foraging habitats and in autumn, adults move to deeper pools of the main river. Larvae drift downstream and settle in floodplain lakes, shallow shores and backwaters with little or no current where the develop before migrating as adults to habitats such as main and side channel borders.

 

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Williamson CJ, Garvey JE. 2005. Growth, fecundity, and diets of newly established silver carp in the Middle Mississippi River. Transactions of the American Fisheries Society 134:1423-1430.

Reproduction

Silver carp spawn from early spring through fall and have the ability to spawn multiple times during a reproductive season. The reproductive potential of silver carp is high and increases with body size. Estimates range from 145,000 to 5,400,000 eggs for fish 3.18 to 12.1 kg. Silver carp mature anywhere from 3-8 years and male silver carp usually mature 1 year earlier than females. Maturation rate of Silver Carp, as in Bighead Carp, has been found to be related to water temperature, requiring 1,000 days at 15°C and 500 days at 30°C.  When Silver carp are ready to spawn, ripples have been seen on the water surface from spawners chasing each other. Males and females ascended close to the water surface, chasing each other and shedding eggs and sperm. Spawning usually occurs in association with a sharp rise in water level because this decreases the possibility of egg mortality and helps larvae to enter floodwaters rich in the food they need. They produce semi-buoyant eggs that are carried by currents through the hatching stage and deposit larvae to slow-flowing backwaters, creeks, reservoirs, or other flooded areas that become nursery areas. Their eggs range in diameter from 4.9 to 5.6 mm, similar to eggs of grass carp but smaller than those of bighead carp. Silver carp eggs need water hardness ranging from 300 to 500 mg/L calcium carbonate to develop and hatch properly otherwise they can burst prematurely in soft water conditions. Freshly deposited eggs that aren’t water hardened yet are clear and can be distinguished from grass carp eggs which have a yellow tinge.

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Papoulias DM, Chapman D, Tillitt DE. 2006. Reproductive condition and occurrence of intersex in bighead and silver carp in the Missouri River. Hydrobiologia 571:355-360.

Characteristic category

Similar Species

Characteristics
Similar Species

Bighead carp (Hypophthalmichthys nobilis) is often confused with silver carp. They’re both from eastern Asia and overlap in both their natural and introduced ranges inhabiting many of the same rivers and lakes. There are a few distinguishing characteristics that separate the two species, however. They have similar shaped bodies but bighead carp are typically dark gray above and cream-colored below with dark gray to black irregular blotches on the back and sides. Their head and mouth are disproportionately large in comparison to their body and other fish species. They have a keel like silver carp however their keel only extends between the anal and pelvic fins. The length of their pectoral fins overlaps their pelvic fins unlike silver carp. The shape of their gill rakers is another useful characteristic in distinguishing the two species. Bighead carp have long, thin gill rakers that are not fused whereas silver carp have gill rakers that are long and thin but are fused to form a sponge-like apparatus. The eyes of both carp species are situated low on the head, but the eyes of bighead carp differ from those of silver carp by facing at a sharper downward angle and more forward on the head. This is especially noticeable when looking at the head from underneath. Bighead carp are also typically grow larger than silver carp reaching lengths upwards of 5 ft in length and weighing over 100 lbs. They, however, do not acrobatically jump out of the water at the sound of motor boats unlike silver carp.

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

[TMWC] Tip of the Mitt Watershed Council. 2021. How to identify Asian carp. Petoskey, MI: Tip of Mitt Watershed Council. Available: https://www.watershedcouncil.org/how-to-identify-asian-carp.html (October 2021).

Geography

Characteristics
Range

Silver carp are native to temperate waters of eastern Asia and can be found in the river systems of the Yangtze, West River, Pearl River, Kwangsi, Kwangtung, and Liao River in southern and central China. They also inhabit the Amur River basin in Russia including the Amur, Amglluy, Arguan, Kerulean, Sungari (Songhuajiang), and Seya Rivers. They are also found in Lake Khanka, Boyr, and Boyan Lake. However, the true native range of silver carp may never be known since they have been introduced widely throughout eastern Asia.Silver carp have successfully invaded the Mississippi River and it’s tributaries after being accidentally introduced from aquaculture and waste water treatment ponds during the 1970’s and 1980’s. They can be found in the Mississippi, Missouri, Ohio, Tennessee, and Cumberland Rivers and many of their tributaries. They have been reported in states such as Alabama, Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Minnesota, Mississippi, Missouri, Nebraska, Nevada, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas, and Wisconsin. 

Kolar CS, Chapman DC, Courtenay WR Jr, Housel CM, Williams JD, Jennings DP. 2005. Asian carps of the genus Hypophthalmichthys (Pisces, Cyprinidae) ― a biological synopsis and environmental risk assessment. Report to U.S. Fish and Wildlife Service per Interagency Agreement 94400-3-0128.

Nico, L.G., Fuller, P., and Li, J. 2021. Hypophthalmichthys molitrix (Valenciennes in Cuvier and Valenciennes, 1844). Gainesville, FL: U.S. Geological Survey, Nonindigenous Aquatic Species Database. Available:  https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=549 (October 2021).

Pendleton RM, Schwinghamer C, Solomon LE, Casper AF. 2017. Competition among river planktivores: are native planktivores still fewer and skinnier in response to the silver carp invasion? Environmental Biology of Fishes 100:1213-1222.

Sass GG, Hinz C, Erickson AC, McClelland NN, McClelland MA, Epifanio JM. 2014. Invasive bighead and silver carp effects on zooplankton communities in the Illinois River, Illinois, USA. Journal of Great Lakes Research 40:911-921. 

Import/Export

Silver carp were introduced to the United States in the 1970’s to help control algae in the aquaculture and wastewater treatment ponds (Norman and Whitledge 2015). They are also a popular food fish that was introduced intentionally and unintentionally throughout the world, mostly for aquaculture purposes as they are the most important aquaculture species in Asia and east central Europe. Silver carp have invaded 88 countries and are reproducing in 23. With native, wild stocks threatened or extirpated, global demand is now primarily met by aquaculture. Globally, over 5.3 million tons of silver carp are cultured annually, primarily in China, India, Bangladesh, Iran, Russia, and Cuba. In the future, there may be a high demand for silver carp from the U.S. since consumers in countries such as China are willing to pay high dollar for wild-caught fish, and may perceive U.S.-sourced fish as higher quality over cultured fish. Currently in the U.S., silver carp are harvested and used in rendered carp products such as meals and oils, as ingredients in livestock and aquaculture feeds, and as fertilizer.

In 2007, the U.S. Fish and Wildlife Service (Service or we) adds all forms of live silver carp (Hypophthalmichthys molitrix), gametes, viable eggs, and hybrids; and all forms of live largescale silver carp (Hypophthalmichthys harmandi), gametes, viable eggs, and hybrids to the list of injurious fish, mollusks, and crustaceans under the Lacey Act. The best available information indicates that this action is necessary to protect the interests of human beings, and wildlife and wildlife resources, from the purposeful or accidental introduction, and subsequent establishment, of silver carp and largescale silver carp populations in ecosystems of the United States. Live silver carp and largescale silver carp, gametes, viable eggs, and hybrids can be imported only by permit for scientific, medical, educational, or zoological purposes, or without a permit by Federal agencies solely for their own use; permits will also be required for the interstate transportation of live silver or largescale silver carp, gametes, viable eggs, or hybrids currently within the United States. Interstate transportation permits may be issued for scientific, medical, educational, or zoological purposes.

Bouska WW, Glover DC, Trushenski JT, Secchi S, Garvey JE, MacNamara R, Coulter DP, Coulter AA, Irons K, Wieland A. 2020. Geographic-scale harvest program to promote invasivorism of bigheaded carps. Fishes 5(29).

Hayer C-A, Breeggemann JJ, Klumb RA, Graeb BDS, Bertrand KN. 2014. Population characteristics of bighead and silver carp on the northwestern front of their North American invasion. Aquatic Invasions 9(3):289-303.

Norman JD, Whitledge GW. 2015. Recruitment sources of invasive bighead carp (Hypopthalmichthys nobilis) and silver carp (H. molitrix) inhabiting the Illinois River. Biological Invasions 17:2999-3014.

Launch Interactive Map