Silver carp, Hypophthalmichthys molitrix, are native to eastern Asia and are commonly found in northeastern China and Siberia. They have also been introduced to other areas of the world, and are now considered invasive to North America. Silver carp have been reported in 16 states in the United States and are well established in the Mississippi River Basin.
Biogeographic Regions: nearctic (Introduced ); palearctic (Native )
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: Native to several major Pacific drainages in eastern Asia from the Amur River south through much of the eastern half of China to Pearl River, possibly including northern Vietnam (see Fuller et al. 1999). Has been collected in Alabama, Arizona, Arkansas, Colorado, Florida, Illinois, Indiana, Kansas, Kentucky, Louisiana, Missouri, and Tennessee; Apparently established in Louisiana (Douglas et al. 1996, Douglas and Jordan 2002) and possibly in Illinois (Fuller et al. 1999).
Silver carp are olive green in color on their dorsal side and silver on the ventral side. They have a deep, laterally compressed body and a large head. Their eyes are located near the ventral side, which makes them easily distinguishable from other carp. Both dorsal and anal fins are present, but an adipose fin is lacking. They have 1 to 3 dorsal spines, 1 to 3 anal spines, 6 to 7 soft dorsal rays, and 10 to 14 sot anal rays. The lateral line is approximately 80 to 130 scales in length. They have numerous thin gill rakers (100 or more). Silver carp are also characterized by a smooth ventral keel on the abdomen that runs from the anus to the gill membrane. Silver carp vary considerably in size; most are relatively small (10 to 30 cm), but some can grow as much as 1 m in length and weigh in excess of 60 pounds (27 kg).
Range mass: 27 (high) kg.
Range length: 105 (high) cm.
Average length: 18 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Amur River Benthopelagic Habitat
This taxon is one of a number of benthopelagic species in the Amur River system. Benthopelagic river fish are found near the bottom of the water column, feeding on benthos and zooplankton
The persistence of mercury contamination in Amur River bottom sediments is a major issue, arising from historic cinnabar mining in the basin and poor waste management practises, especially in the communist Soviet era, where industrial development was placed ahead of sound conservation practises.
Other large benthopelagic river fish of the Amur Basin is the 200 cm yellowcheek (Elopichthys bambusa) and the 122 cm Mongolian redfin (Chanodichthys mongolicus)
Yangtze River Benthopelagic Habitat
This taxon is one of a number of benthopelagic species in the Yangtze River system. Benthopelagic fish inhabit the water column niche immediately above the bottom, feeding on benthos and zooplankton.
The upper Yangtze basin consists chiefly of Paleozoic limestone and terrigenous sedimentary rock, with some granitic material. The most downstream element of the upper Yangtze basin is often termed the Sichuan Basin; here the Yangtze cuts through Triassic and Permian material before entering the Three Gorges. The Three Gorges area is a stretch of the Yangtze that runs approximately 660 kilometers, terminating at the site of the Three Gorges Dam. Prior to construction of the dam, the Three Gorges area was a site of exceptional natural beauty; after dam construction the gorge areas were filled with approximately 100 meters in depth of Yangtze water, and considerable amounts of the watershed were graded.
The lower Yangtze basin consists of anabranching river structures and Pleistocene coastal terraces. Prior to development of the Three Gorges Dam, the Yangtze Delta was replenished with a copious sediment load reaching the river mouth; however, the dam has now severely limited the natural flow and deposition of sediment to the delta region. Consequently, the integrity of the delta is been compromised, with scouring exceeding deposition, and the very stability of the delta is endangered.
Lower and middle basins of the Yangtze carry heavy pollutant loads. In the lower Yangtze basin nitrate levels are high, measuring at about 1000 tons per day at Datong; these levels accrue from high applications of chemical fertilizer applied and also considerable loadings of untreated sewage due to the large human population of the basin, with correspondingly little infrastructure for sewage treatment.
Heavy metal concentrations are also high in the lower Yangtze, with measurements of dissolved lead at 0.078 microgram/liter; cadmium (0.024 microgram/liter), chromium (0.57 microgram/liter), copper (1.9 microgram/liter), and nickel (0.50 microgram/liter). Levels of dissolved arsenic have been measured at 3.3 microgram/liter) and zinc at 1.5 microgram/liter), both notably higher by factors of 5.5 and 2.5 respectively than other typical large world rivers. In Yangtze River suspended sediment, arsenic comprises 31 microgram/gram, lead comprises 83 microgram/gram, and nickel comprises 52 micrograms/gram of sediment content
A number of other benthopelagic associates are found in the Yangtze, including: Anabarilius polylepis, Bangana rendahli, Pseudogyrinocheilus prochilus, Sinocyclocheilus grahami and Siniperca roulei. The demersal fish Silurus meridionalis also is found as a Yangtze River endemic species.
Silver carp live in freshwater in temperate (6 to 28 °C) to subtropical climates. They are commonly found in impoundments or backwaters of large slow flowing rivers or large lakes. Silver carp are benthopelagic, but they often swim near the surface of the water and are well known for breaching the surface. They can tolerate brackish waters (up to 12 ppt) as well as low dissolved oxygen content (3 mg/l).
Habitat Regions: temperate ; freshwater
Aquatic Biomes: benthic ; lakes and ponds; rivers and streams
Habitat and Ecology
Dams have greatly impacted the species reproductive success. The Amur populations are thought not to have yet been impacted (M. Kottelat pers. comm. 2011), however populations in China have declined greatly as a result of the widespread development of dams.
Habitat Type: Freshwater
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Silver carp are filter feeders, feeding primarily on phytoplankton. Using specialized gill rakers covered with a thick matrix of calcified substances, silver carp are able to filter out the very smallest organisms (ranging in size from 8 to 100 micrometers). However, only a small part of their diet consists of zooplankton and detritus. Silver carp may also eat small arthropods and algea.
Animal Foods: aquatic crustaceans; zooplankton
Plant Foods: algae; phytoplankton
Other Foods: detritus
Foraging Behavior: filter-feeding
Primary Diet: planktivore
Silver carp are considered invasive in North America. They were initially introduced into the United States in the 1970’s to control plankton blooms but have subsequently spread into 16 states after escaping from aquaculture centers. Silver carp can adapt to many different environments and can grow very quickly. They can consume 2 to 3 times their body weight in plankton each day. In controlled experiments, silver carp gained 2.7 g/day when fed a large diet. Because of their large size and voracious appetite, silver carp are able to out-compete many other species of fish.
Adult silver carp do not have any natural predators. However, fry are subject to predation from other fish and possibly birds.
Diseases and Parasites
Life History and Behavior
Like many other fish, silver carp use their lateral line system to detect motions and vibrations. As filter feeders, however, they do not rely as heavily on their lateral line system as do predatory fish. Silver carp also utilize their senses of sight and smell. Reproduction is often cued by increases in water temperature as well as olfactory cues.
Communication Channels: visual ; chemical
Perception Channels: visual ; tactile ; vibrations ; chemical
Eggs of silver carp reach maturity when they are about 3.2 to 4.7 mm in size. Young enter the larval stage about 68 hours after hatching. During the larval stage, fry are vulnerable and inefficient feeders. After about 5 months, fry have grown to a size of 8 to 12 cm in body length and have become more efficient feeders. Silver carp reach maturity at 4 to 6 years of age, at which point they are capable of reproduction.
With substantial food sources and few natural predators, silver carp can grow quite large and can live many years. Silver carp may live as long as 20 years in the wild, and may be capable of living longer.
Status: wild: 20 (high) years.
Silver carp generally reproduce during the spring or summer. Reproduction is primarily cued by increased water temperature. Like other species of carp, silver carp participate in broadcast spawning. During spawning, a female releases eggs and males fertilize them within the water column. A single female can carry as many as 2 million eggs.
Mating System: polygynandrous (promiscuous)
Spawning of silver carp takes place upstream and generally occurs in spring or summer. Optimal water temperatures for spawning range from 22 to 28 °C. Females release eggs in the water column, where they are then fertilized by many males. Fertilized eggs float downstream to floodplain zones where they absorb water and eventually settle to hatch. Silver carp reach sexual maturity at 4 to 6 years of age.
Breeding interval: Silver carp breed once yearly.
Breeding season: Spawning of silver carp occurs during spring or early summer.
Range age at sexual or reproductive maturity (female): 4 to 6 years.
Range age at sexual or reproductive maturity (male): 4 to 6 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning; oviparous
Silver carp do not demonstrate parental investment in their offspring. After eggs are released into and fertilized in the water column, silver carp leave the area and do not return.
Parental Investment: no parental involvement
Molecular Biology and Genetics
Barcode data: Hypophthalmichthys molitrix
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Hypophthalmichthys molitrix
Public Records: 15
Specimens with Barcodes: 15
Species With Barcodes: 1
Due to their rapid growth rate and worldwide popularity, silver carp are not considered threatened. They are often sold for human consumption and are also used for cleaning waters of algael blooms.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: no special status
IUCN Red List Assessment
Red List Category
Red List Criteria
It is assessed as Near Threatened due the the scale of wild population decline in China, as it is suspected to be close to meeting a threatened category under population decline (category A2). Monitoring of population trends and reproductive success in the wild is needed.
National NatureServe Conservation Status
Rounded National Status Rank: NNA - Not Applicable
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Relevance to Humans and Ecosystems
The lasting effects of silver carp as invasive spices on local ecosystems remains to be seen.
Silver carp are becoming increasing popular sources of food. They are also commonly used to clear algal blooms. Harvesting of silver carp increased from 1.9 million tons in 1993 to 4.1 million tons in 2003. Because silver carp do not require supplementary feed like other species of farm grown fish, they have become popular worldwide.
Positive Impacts: food ; controls pest population
|This article may require cleanup to meet Wikipedia's quality standards. The specific problem is: unprofessional tone. (November 2014)|
The silver carp (Hypophthalmichthys molitrix) is a species of freshwater cyprinid fish, a variety of Asian carp native to China and Eastern Siberia. It is cultivated in China. Pound for pound, more silver carp are produced worldwide in aquaculture than any other species. They are usually farmed in polyculture with other Asian carp, or sometimes Indian carp or other species. It has been introduced to, or spread by connected waterways, into at least 88 countries around the world. The most common reason for importation was for use in aquaculture, but enhancement of wild fisheries and water quality control were also important reasons for importation. The silver carp reaches an average length of 60-100 cm (24-39 in) with a maximum of 140 cm (55 in) and about 45 kg (99 lb).
The silver carp is a filter feeder, and possesses a remarkably specialized apparatus capable of filtering particles as small as 4 micrometers (µm). The gill rakers are fused into a sponge-like filter, and an epibranchial organ secretes mucus which assists in trapping small particles. A strong buccal pump forces water through this filter. Silver carp, like all Hypophthalmichthys species, have no stomachs; they are thought to feed more or less constantly, largely on phytoplankton; they also consume zooplankton and detritus. Because of their plankton-feeding habits, there is concern they will compete with native planktivorous fishes, which in North America include paddlefish (Polyodon spathula), gizzard shad (Dorosoma cepedianum), and young fish of almost all species.
Because they feed on plankton, they are sometimes successfully used for controlling water quality, especially in the control of noxious blue-green algae (cyanobacteria). However, these efforts are sometimes not successful. Certain species of blue-green algae, notably the often toxic Microcystis, can pass through the gut of silver carp unharmed, and pick up nutrients while in the gut. Thus, in some cases, blue-green algae blooms have been exacerbated by silver carp. Also, Microcystis has been shown to produce more toxins in the presence of silver carp. These carp, which have natural defenses to their toxins, sometimes can contain enough algal toxins in their systems to become hazardous to eat.
Silver carp are filter feeders, thus are difficult to catch on typical hook-and-line gear. Special methods have been developed for these fish, the most important being the "suspension method", usually consisting of a large dough ball that disintegrates slowly, surrounded by a nest of tiny hooks embedded in the bait. The entire apparatus is suspended below a large bobber. The fish feed on the small particles released from the dough ball and bump against the dough ball, with the intention of breaking off more small particles that can be filtered from the water, eventually becoming hooked on the tiny hooks.
In some areas, it is also legal to use "snagging gear", in which large, weighted treble hooks are jerked through the water, to snag the fish. In the United States, silver carp are also popular targets for bowfishermen; they are shot both in the water and in the air. In the latter case, boats are used to scare the fish and entice them to jump, and the fish are shot when they jump.
The genus Hypophthalmichthys has two other species, the bighead carp (H. nobilis) and the largescale silver carp (H. harmandi). The genus Aristichthys is also sometimes used for bighead carp, but this genus was based on fallacious theory and should no longer be used. The bighead carp differs from the silver carp in its behavior (it does not leap from the water when startled) and also in its diet. Bighead carp are also filter feeders, but they filter larger particles than silver carp and in general consume a greater proportion of zooplankton in their diets than silver carp, which consume more phytoplankton. In at least some parts of the United States, bighead and silver carp hybridize in the wild and produce fertile offspring.
The largescale silver carp is very closely related to the silver carp, but its native range is to the south of that of the silver carp, mostly within Vietnam. Unlike bighead and silver carp, largescale silver carp have not been widely introduced around the world for use in aquaculture, although at least one introduction was made to some waters of the Soviet Union, where they hybridized with the introduced silver carp.
In North America
Silver carp were imported to North America in the 1970s to control algae growth in aquaculture and municipal wastewater treatment facilities. They escaped from captivity soon after their importation. They are considered a highly invasive species. Silver carp, with the closely related bighead carp, often reach extremely high population densities, and are thought to have undesirable effects on the environment and native species.
By 2003, silver carp had spread into the Mississippi, Illinois, Ohio, and Missouri Rivers and many of their tributaries in the United States. By August 2009, they had become abundant in the Mississippi River watershed from Louisiana to South Dakota and Illinois, and had grown close to invading the Great Lakes via the Chicago Sanitary and Ship Canal. Navigation dams seem to have slowed their advance up the Mississippi River, and until late November 2008, silver carp had not been captured north of central Iowa on the Mississippi. Dams that do not have navigation locks are complete barriers to upstream natural movement of silver carp, and it is important for fishermen not to assist this movement by the unintentional use of silver carp as bait.
The silver carp is also called the flying carp for its tendency to leap from the water when startled. They can grow to over 40 lb (18 kg), and can leap 10 ft (3 m) in the air. Many boaters traveling in uncovered high-speed watercraft have been injured by running into the fish while at speed. In 2003, a woman jet-skiing broke her nose and a vertebra by colliding with a silver carp, and nearly drowned. In another example, a leaping silver carp broke the jaw of a teenager being pulled on an inner tube. Water skiing in areas where silver carp are present is extremely dangerous. British biologist and angler Jeremy Wade was hit by one in the head while on the Illinois River filming for the second season River Monsters.
- Froese, Rainer and Pauly, Daniel, eds. (2006). "Hypophthalmichthys molitrix" in FishBase. April 2006 version.
- Kolar et al. 2005. Asian Carps of the Genus Hypophthalmichthys (Pisces, Cyprinidae) ― A Biological Synopsis and Environmental Risk Assessment
- Kolar et al. 2007. Bigheaded Carps: Biological Synopsis and Environmental Risk Assessment. American Fisheries Society, Bethesda, MD.
- ACBSRA Final Report 2005
- USGS NAS silver carp fact sheet
- Conover et al. 2007 Management and Control Plan for Bighead, Black, Grass, and Silver Carps in the United States. Aquatic Nuisance Species Task Force, Washington, D.C. 223 pp. http://www.anstaskforce.gov/Documents/Carps_Management_Plan.pdf
- Irons et al. 2007. Reduced condition factor of two native fish species coincident with invasion of non-native Asian carps in the Illinois River, U.S.A. Is this evidence for competition and reduced fitness? Journal of Fish Biology 71:258-273
- USGS CERC bighead and silver carp fact sheet
- Moritz, R. 2008. Pesky 'flying' carp causing problems in SE Arkansas. http://www.arkansasnews.com/archive/2008/09/07/News/347862.html
- Maclean's Apr. 17 2006 pg. 39
- "Great Flying Carp! Fish A Threat To Boaters, Skiers". The Courier-Journal. 12 March 2004. Archived from the original on 5 April 2013.
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