Cyprinus rubrofuscus Ecological Risk Screening Summary

Koi (Cyprinus rubrofuscus)

Ecological Risk Screening Summary

U.S. Fish and Wildlife Service, September 2011

Revised, September 2019

Web Version, 1/7/2020

Photo: Chinese Academy of Fishery Sciences. Licensed under CC BY-NC 3.0. Available:

https://www.fishbase.de/photos/PicturesSummary.php?ID=59920&what=species. (September

2018).

1 Native Range and Status in the United States

Native Range

From Huckstorf (2012):

“The species has an east Asian distribution. It is distributed from the Amur to Red River

drainages (Kottelat 2006) in Mongolia, Russia (Amur), eastern China, Lao PDR, and Viet Nam.”

Status in the United States

Daniel et al. (2019) report nonindigenous occurrences of Cyprinus rubrofuscus from the

following U.S. states and HUCs during the stated timeframes: Delaware, 2014-2018 (Broadkill-

Smyrna); Florida, 1997-2019 (Florida Southeast Coast, Hillsborough, Kissimmee, Lower

Ochlockonee, Oklawaha, Upper St. Johns); Kentucky, 2019; Louisiana, 2004-2018 (Liberty

Bayou-Tchefuncta, Toledo Bend Reservoir); Maine, 2008 (Saco); Massachusetts, 2016 (Cape

Cod); Minnesota, 2004-2016 (Lake Superior, Twin Cities); Nevada, 2016 (Las Vegas Wash);

New Jersey, 2006-2009 (Crosswicks-Neshaminy, Mullica-Toms); New York, 2011 (Niagara);

North Carolina, 2019 (Haw); Pennsylvania, 2007-2016 (Crosswicks-Neshaminy, Schuylkill);

South Dakota, 2003 (Middle Cheyenne-Spring).

Domesticated Koi (scientific name not specified) are in trade in the United States.

From Koi To The World (2019):

“Lot Of (15) Assorted 5-8" Koi […] $ 300.00”

Means of Introductions in the United States

From Mitrica (2015):

“In the Colorado Lake, 3,000 Koi fish (Japanese carp) are now swarming the water, wiping out

native species and dramatically altering the environment.”

“It’s not clear why, when and how the fish popped up in the lake – the explosion of these exotic

fish which are not native to North America seems to have occurred three years ago, and

authorities suspect that a local pet store is responsible. The fact that all the fish seem to be some

three years old seems to be telling for that aspect.”

““Based on their size, it looks like they’re 3-year-olds, which were probably produced from a

small handful of fish that were illegally introduced into the lake,” Ben Swigle, a fish biologist at

the Colorado Parks and Wildlife (CPW), told Live Science.”

Remarks

All scientific name synonyms of C. rubrofuscus listed below were used to search for information

for this report. Cyprinus rubrofuscus, Koi, is commonly confused with Common Carp, Cyprinus

carpio. Literature discussing domesticated, ornamental Koi will often refer to it using the

scientific name Cyprinus carpio. While every effort was made to limit the information in this

report to that applicable to C. rubrofuscus, it was not always possible to determine with certainty

which species was being referenced in literature discussing ornamental Koi.

From Daniel et al. (2019):

“Koi (Cyprinus rubrofuscus) are ornamental varieties of domesticated carp that are often

erroneously identified as European Carp (C. carpio) (Kottelat and Freyhof 2007).”

“The koi has gone through a lot of taxonomic changes due to extensive cultivation and breeding

history (Gross et al 2002; Zhou et al 2003a), and its origins are uncertain, leaving its taxonomic

status ambiguous (Dong et al. 2015). Gross et al (2002) found koi to be a distinct monophyletic

group resulting from domestication, but more closely related to East Asian carp groups, and

recognized as the subspecies Cyprinus carpio haematopterus; this was also the conclusion and

taxonomic assignment in similar studies from the same time period that used allozyme data

(Kohlmann and Kersten 1999; Zhou et al 2013b). Literature from a decade later has also

recognized koi as carp subspecies Cyprinus carpio haematopterus (Kim et al 2018; Zoran et al

2017). Matsui et al (2008) recongnized [sic] koi as a carp subspecies Cyprinus carpio koi.

Athough [sic] Zhou et al (2003b) used the subspecies name rubrofuscus to describe other carp

strains, Eschmeyer’s Catalog of Fishes, as well as the Integrated Taxonomic Information System

(ITIS), recognizes the species Cyprinus rubrofuscus as of June 2019 (Fricke et al 2019), putting

a lot of the other subspecies assigned to the koi as synonyms (Dong et al. 2015).”

From Huckstorf (2012):

“Cyprinus rubrofuscus is the species commonly identified as the common carp, C. carpio, a

species native to eastern Europe and central Asia. Contrary to what is often believed, the

European carp is not introduced in Europe from Asia (Kottelat 1997, Kottelat 2001). Cyprinus

carpio has been introduced worldwide, but many cultivated stocks in Asia are in fact C.

rubrofuscus, a species native to Eastern Asia (China, and probably Japan and Viet Nam). The

molecular data of Zhou et al. (2004) support this conclusion although these authors did not

discuss the taxonomy aspect of their results.”

From Naseka and Bogutskaya (2004):

“The Amur carp is widely treated as subspecies C. carpio haematopterus Temminck & Schlegel

in the Russian literature. However, the name Cyprinus haematopterus Temminck & Schlegel,

1846[…] is permanently invalid as a junior primary homonym of Cyprinus haematopterus

Rafinesque, 1820 (Eschmeyer, 1998). The earliest available name for the Amur (Asian) carp is

Cyprinus rubrofuscus La Cepède, 1803[…], and this taxon has been commonly considered a

subspecies, C. carpio rubrofuscus, in the recent Chinese literature (Chen & Huang, 1977; Zhu,

1995; etc.). Kottelat (2001a, 2001b) considers it to be a distinct species.”

From Huckstorf (2012):

“Synonym(s):

Cyprinus carpio Linnaeus, 1758 ssp. murgo Dybowski, 1869

Cyprinus flammans Richardson, 1846

Cyprinus fossicola Richardson, 1846

Cyprinus nigroauratus Lacepède, 1803

Cyprinus annacarolina Lacepède, 1803

Cyprinus carpio Linnaeus, 1758 ssp. yuankiang Wu et al., 1963

Cyprinus floripenna van Hasselt, 1823

Cyprinus haematopterus Temminck & Schlegel, 1846

Cyprinus hybiscoides Richardson, 1846

Cyprinus sculponeatus Richardson, 1846

Cyprinus viridiviolaceus Lacepède, 1803”

2 Biology and Ecology

Taxonomic Hierarchy and Taxonomic Standing

From ITIS (2018):

“Kingdom Animalia

Subkingdom Bilateria

Infrakingdom Deuterostomia

Phylum Chordata

Subphylum Vertebrata

Infraphylum Gnathostomata

Superclass Actinopterygii

Class Teleostei

Superorder Ostariophysi

Order Cypriniformes

Superfamily Cyprinoidea

Family Cyprinidae

Genus Cyprinus

Species Cyprinus rubrofuscus Lacepède, 1803”

From Fricke et al. (2019):

“Current status: Valid as Cyprinus rubrofuscus Lacepède 1803. Cyprinidae: Cyprininae.”

Size, Weight, and Age Range

From Daniel et al. (2019):

“Size: 30 to 60 cm long (Tomelleri and Eberle 1990)”

“Koi are long-lived and have a typical life span of around 40 years, but the oldest-known koi

lived to be 230 years old. They reach sexual maturity around age 4 and breed yearly thereafter

(Smithsonian National Zoo and Conservation Biology Institute 2019).”

Environment

From Froese and Pauly (2018):

“Freshwater; brackish; benthopelagic.”

“Found in freshwater, but tolerant to slightly brackish water [Bogutskaya et al. 2008].”

Climate/Range

From Froese and Pauly (2018):

“Tropical”

Distribution Outside the United States

Native

From Huckstorf (2012):

“The species has an east Asian distribution. It is distributed from the Amur to Red River

drainages (Kottelat 2006) in Mongolia, Russia (Amur), eastern China, Lao PDR, and Viet Nam.”

Introduced

From Magalhães and Jacobi (2013a):

“Among the 65 non-native aquarium fish currently found in Brazilian inland waters are seven

cyprinids, […] [including] koi carp Cyprinus rubrofuscus Lacepéde 1803, […]”

From Freyhof and Kottelat (2008):

“[…] C. rubrofuscus (often erroneously referred to as C. carpio haematopterus) is cultivated in

several eastern European countries and has been introduced to Russia and Ukraine. It is not

known whether it has become established there.”

Yang et al. (2011) find genetic evidence of C. rubrofuscus (as C. carpio haematopterus) in

Xingyun Lake, central Yunnan Province, China.

From Centre for Invasive Species Solutions (2017):

“Carp populations in the upper Murrumbidgee catchment (Lake Burrinjuck in New South Wales

and Lake Burley Griffin in the Australian Capital Territory), the Upper Lachlan catchment,

several coastal catchments in New South Wales, lakes Crescent and Sorell in Tasmania and

wetlands near Perth in Western Australia have some koi ancestry. Some established wild

populations in coastal New South Wales are made up entirely of highly coloured koi strain fish.”

From The University of Waikato (2019):

“The species is thought to have been introduced to New Zealand waters in the 1960s. […] Feral

breeding stocks were first noticed in the Waikato River in 1983. They are now very common

throughout the lower Waikato River regions – spreading into streams, lakes and wetlands.”

“Koi carp are widespread in the Waikato and Auckland and are spreading further north. They

have also been found in Wanganui, Hawke’s Bay and Wellington but have not yet been found in

the South Island.”

Means of Introduction Outside the United States

From Magalhães and Jacobi (2013b):

“Cyprinus rubrofuscus (common variety) that escaped from fish farms has great importance in

commercial fishing in several lotic and lentic environments in the Doce River basin (Vieira,

2010). The same trend of spread may occur with Cyprinus rubrofuscus - koi if released by

hobbyists in the studied rivers. Feral koi carp released by aquarium amateurs has established

itself and dispersed in a number of rivers and lakes of New Zealand (Tempero et al., 2006).”

From Freyhof and Kottelat (2008):

“In western Europe, Japanese ornamental varieties (kois) possibly derived from C. rubrofuscus

or of hybrid origin occasionally escape from ponds.”

From Yang et al. (2011):

“According to historical records from the Xingyun Lake Protection Bureau, a fish farm near the

lake [Xingyun Lake, Yunnan Province, China] introduced this strain of carp from northern

China.”

From Centre for Invasive Species Solutions (2017):

“There have […] been multiple releases of the Japanese ‘koi strain’ of carp [in Australia], all

relatively recently (1976—2008). It is likely that many of these releases originated from locally

cultured fish rather than direct introductions from Japan.”

From The University of Waikato (2019):

“The species is thought to have been introduced to New Zealand waters in the 1960s. They may

have been released accidently from ponds during flooding. Some may have been released for

fishing purposes.”

From Hanchet (1990):

“The introduction of koi into New Zealand waters is undocumented, but they were probably

brought into the country in a consignment of goldfish (Carassius auratus), from which they are

difficult to distinguish as juveniles (McDowall 1979). Since koi arrived in New Zealand, they

have been bred and introduced into many farm ponds and dams, mainly in the north of the North

Island.”

Short Description

From Freyhof and Kottelat (2008):

“Wild C. rubrofuscus are distinguished from wild C. carpio by having 29-33 + 2-3 lateral line

scales (vs. 33-37 + 2-3), 18-22½ branched dorsal rays (vs. 17-20½), body silvery with red pelvic,

anal and lower caudal lobe (vs. grey to bronze).”

From Froese and Pauly (2018):

“Body silvery with red pelvic, anal and lower caudal lobe (Xiangkhouang stock) or grey (Louang

Phabang stock, Laos). Last simple anal ray bony and serrated posteriorly; with 4 barbels;

branched dorsal rays 18-22.5 [Kottelat 2001a].”

From Daniel et al. (2019):

“Koi are a domesticated ornamental carp taxa that vary widely in coloration with combinations

of bright gold, orange, silver, white, and black colors patterns (Kottelat and Freyhof 2007). Koi

are characterized by their deep body, two barbels on each side of its upper jaw, and serrated

dorsal spine (Nelson 1984).”

Biology

From The University of Waikato (2019):

“Waikato koi rarely exceed 9 years of age. Females average 5.2 years and males 4.6 years of age.

An average fish weighs 3 kg. Females produce 100 000 eggs per kg of body weight. A typical

female can produce 300 000 eggs annually (or more if they spawn more than once). Koi carp

spawn throughout the summer. As they gather for spawning or feeding in the shallow margins of

the river, koi biomass can reach 4000 kg/ha.”

“Koi carp feed like vacuum cleaners – moving along the bottoms of streams, lakes and rivers.

Koi carp are opportunistic feeders eating a wide variety of benthic organisms – plants and

animals. They suck up and expel material from the bottom, filtering out edible material as they

go. They grind their food to a pulp with powerful teeth located in their throats, making a noise

that can be heard underwater through a hydrophone.”

“Koi carp prefer still waters, spreading from rivers into lakes, streams or backwaters in rivers.

They are highly tolerant of poor water quality – surviving well in degraded water and

contributing to the decline.”

Human Uses

From Huckstorf (2012):

“This species is a commercial fishery target. It is extensively used in aquaculture.”

From Cornwell et al. (2013):

“Koi Carp Cyprinus carpio represent a major portion of U.S. ornamental fish aquaculture.

Although other ornamental species have greater total sales, more farms raise Koi than any other

ornamental fish species in the USA. In 2005, there were 193 farms in the USA culturing Koi,

with sales totaling more than US$6.5 million (USDA 2006).”

Cornwell et al. (2013) report the scientific name of Koi Carp as Cyprinus carpio, but ornamental

Koi are likely Cyprinus rubrofuscus.

Diseases

From Daniel et al. (2019):

“Koi carry and transmit the koi herpesvirus (KHV) disease, which can result in large die-offs of

many carp groups (Matsui et al. 2008). The species is also capable of becoming infected with

carp oedema virus (CEV), which causes koi sleepy disease (KSD) and results in sickness and the

eventual death of the fish from anoxia, which can affect the ornamental koi industry, as there is a

100% motality rate for the disease (Kim et al. 2017).”

From Goodwin (2002):

“The United States is a major producer of fish species susceptible to SVCV [spring viremia of

carp virus], including […] koi (a strain of common carp) […].”

From Cornwell et al. (2013):

“In this study, 80 Koi were exposed to VHSV [viral hemorrhagic septicemia virus] by

intraperitoneal injection. Mortality was very low and occurred in the first 2 d of the experiment,

suggesting that deaths could be due to handling stress and not VHSV infection. Nevertheless, the

results of this experiment provide strong evidence that Koi have the potential to become infected

with VHSV IVb. Two Koi showed mild clinical signs associated with VHSV infection. The virus

quantity present in fish increased slightly but significantly between exposure and the first 2

weeks postexposure. In addition, infectious VHSV was isolated from many fish up to 28 DPE.

Virus was detected by qRT-PCR up to 90 DPE […], albeit at very low levels, suggesting that

Koi have the potential to be long-term carriers of VHSV viral genomic material, although it is

not known at this point whether virus remaining at these later time points is viable, infectious

virus.”

Cornwell et al. (2013) report the scientific name of Koi Carp as Cyprinus carpio but they also

note that commercially-bred ornamental Koi were tested for infection with VHSV, so these

individuals were likely Cyprinus rubrofuscus.

OIE (2019) lists “Infection with koi herpesvirus,” “Infection with spring viraemia of carp virus,”

and “Infection with viral haemorrhagic septicaemia virus” in its “OIE-Listed diseases, infections

and infestations in force in 2019”.

Threat to Humans

From Froese and Pauly (2018):

“Harmless”

3 Impacts of Introductions

From Magalhães and Jacobi (2013b):

“There are no studies showing the adverse ecological effects of introducing Cyprinus

rubrofuscus - koi, […] by hobbyists in Minas Gerais or elsewhere in Brazil.”

From The University of Waikato (2019):

“Koi carp feed like vacuum cleaners – moving along the bottoms of streams, lakes and rivers.

Koi carp are opportunistic feeders eating a wide variety of benthic organisms – plants and

animals. They suck up and expel material from the bottom, filtering out edible material as they

go.”

“This activity destroys native plant, fish, invertebrate and water bird habitat. It stirs up the

substrate and can greatly increase the turbidity of the water. Waterways become muddy and

unattractive. Aquatic plants are dislodged and are unlikely to re-establish. Oxygen is depleted.”

From Rowe (2007):

“Changes in water clarity (secchi disc transparency) in relation to the presence/absence of

introduced, exotic fish, including rudd (Scardinius erythrophthalmus), tench (Tinca tinca), perch

(Perca fluviatilis), brown bullhead catfish (Ameiurus nebulosus), goldfish (Carassius auratus),

and koi carp (Cyprinus carpio) were determined for 49 small, North Island, New Zealand lakes.

There was a negative association between water clarity and the presence of exotic fish

independent of lake depth. Moreover, a ‘before-and-after’ comparison and examination of case-

studies indicated that introductions of exotic fish reduce water clarity. The number of species

introduced affected the relationship between lake depth and water clarity but the specific role of

each species could not be distinguished because most of the lakes (83%) contained more than

one exotic fish species.”

Rowe (2007) report the scientific name of Koi Carp as Cyprinus carpio, but ornamental Koi are

likely Cyprinus rubrofuscus.

From Hanchet (1990):

“The impacts of koi on the New Zealand aquatic environment are extremely difficult to predict.

Firstly, we have little information on whether their growth, reproduction, feeding habits, and

general behaviour are similar to some of the more virulent strains of carp overseas […]

Secondly, we have little information on the densities of koi attained in New Zealand, and at what

densities any impacts to vegetation will eventuate. Furthermore, the effects of carp on many of

our exotic plants (e.g., Egeria densa, Lagarosiphon major, and Vallisneria gigantea) and native

plants (e.g., Potamogeton spp., Myriophyllum spp.) are unknown. Lastly, the principal, large,

predatory fish in New Zealand (eels and trout) are largely absent from those areas in North

America where carp have been a problem, and therefore their role in regulating koi numbers is

unknown.”

“In January 1988, MAF Fisheries [New Zealand’s Ministry of Agriculture and Fisheries] was

aware of only three waterbodies where koi apparently have had a major impact on the aquatic

environment. The first waterbody, called Harrison's Pond, is on a farm north of Auckland. The

pond is 440 m long by 67 m wide, is 2 ha in area, and has an average water depth of 1 m

(maximum depth, 3 m). It was sampled in August 1986 by MAF Fisheries, using gill nets and

fyke nets. Nineteen koi, 49 eels, seven rudd, and two goldfish were caught (S. Pullan, pers.

comm.). Details of the date and number of koi originally released into the pond are unknown.

The presence of several size classes of koi in the catch suggests that these fish have successfully

bred there. The pond had a surface temperature of l3.7°C, a Secchi disk reading of 475 mm, a

mud substrate, and very sparse aquatic vegetation (algae, watercress, and willow weed). Mr

Harrison (the landowner) stated that, since koi had been introduced, there had been a reduction in

aquatic vegetation (quantity and species unknown) and that the ducks previously present had

disappeared. The koi caught in Harrison's Pond were in poor condition compared to koi caught in

the Waikato River. This suggests that there was a shortage of food in the pond and that the

density of koi was probably high. No biomass estimates are available for this pond.”

“The second waterbody is a small pond on a farm in Taranaki (Pullan 1982). The pond has an

area of about 0.2 ha with an average water depth of 2 m. It was surveyed by S. Pullan in

December 1981, and, using gelignite, a total of 22 koi was removed. Ten koi survived the blasts,

but eight of these fish were later removed (Pullan [1984]). The fish were on average 40-50 cm

long, and weighed between 1.5 kg and 4.8 kg, giving an estimated density of 440 kg/ha. After the

koi were removed, dense regrowth of vegetation occurred (S. Pullan, pers. comm.).”

“The third waterbody is also a small (0.05 ha) pond, about 1.0 - 1.5 m depth, near Ohaupo, south

of Hamilton. The water has apparently become turbid, and lost its vegetation since koi were

liberated (S. Pullan, pers. comm.). No attempt has been made to sample the waterbody, and so no

estimate of fish density is available.”

4 Global Distribution

Figure 1. Known global distribution of Cyprinus rubrofuscus. Map from GBIF Secretariat

(2019). Most occurrences represent ornamental Koi, not wild-type individuals. It could not be

determined which occurrence points represent fish being raised in captivity and which are living

in the wild.

5 Distribution Within the United States

Figure 2. Known distribution of Cyprinus rubrofuscus in the United States. Map from Daniel et

al. (2019). Yellow diamonds represent established populations; orange diamonds represent

populations with a status of “collected,” “eradicated,” “extirpated,” “failed,” or “unknown.”

6 Climate Matching

Summary of Climate Matching Analysis

The Climate 6 score (Sanders et al. 2018; 16 climate variables; Euclidean distance) for the

contiguous United States was 0.957, which is a high climate match. A Climate 6 score of 0.103

or greater indicates a high match. The climate match was categorically high in all states in the

contiguous United States, but there were several small areas of low match in the Pacific

Northwest.

Figure 3. RAMP (Sanders et al. 2018) source map showing weather stations selected as source

locations (red) and non-source locations (gray) for Cyprinus rubrofuscus climate matching.

Source locations from GBIF Secretariat (2019).

Figure 4. Map of RAMP (Sanders et al. 2018) climate matches for Cyprinus rubrofuscus in the

contiguous United States based on source locations reported by GBIF Secretariat (2019). Counts

of climate match scores are tabulated on the left. 0= Lowest match, 10=Highest match.

The “High”, “Medium”, and “Low” climate match categories are based on the following table:

Climate 6: Proportion of

(Sum of Climate Scores 6-10) / (Sum of total Climate Scores)

Climate Match

Category

0.000<X<0.005

Low

0.005<X<0.103

Medium

≥0.103

High

7 Certainty of Assessment

Despite the ubiquity of Koi in aquaculture, there is relatively little information available about

the biology of this species in the wild. There is anecdotal evidence that the species has negative

impacts on aquatic vegetation, but more robust research is necessary. Because the domesticated

fish commonly referred to as Koi is often called Cyprinus carpio in scientific literature, as

opposed to Cyprinus rubrofuscus, it cannot be determined which species is being referenced with

certainty. Further information clarifying the taxonomy of domesticated Koi is necessary to assess

the risk Cyprinus rubrofuscus poses to the contiguous United States with certainty. Certainty of

this assessment is low.

8 Risk Assessment

Summary of Risk to the Contiguous United States

Cyprinus rubrofuscus, the Koi, is a freshwater carp species native to eastern Asia. Although

domesticated Koi are often known by the scientific name Cyprinus carpio, also known as

Common Carp, Koi are more likely bred from wild Cyprinus rubrofuscus. Domesticated Koi are

bred for many highly ornamental characteristics and are available in shades of gold, silver, white,

orange, and black. C. rubrofuscus has been widely introduced outside of its native range. It is not

clear what impacts it is having where introduced, so the history of invasiveness is classified as

“none documented.” This species is reported to have negative impacts in New Zealand, but the

evidence is either anecdotal or any impacts of C. rubrofuscus are confounded with the impacts of

other nonnative species. This species has a very high climate match with the contiguous United

States; however, confidence in the results of the climate matching analysis is reduced because it

could not be determined which occurrence points represented domesticated fish and which were

feral. Certainty of this assessment is low. The overall risk assessment category is Uncertain.

Assessment Elements

 History of Invasiveness (Sec. 3): None Documented

 Climate Match (Sec. 6): High

 Certainty of Assessment (Sec. 7): Low

 Important additional information: Susceptible to three OIE-reportable diseases.

 Overall Risk Assessment Category: Uncertain

9 References

Note: The following references were accessed for this ERSS. References cited within quoted

text but not accessed are included below in Section 10.

Centre for Invasive Species Solutions. 2017. PestSmart Factsheet: Introduction and distribution

of carp in Australia. Available: https://www.pestsmart.org.au/wp-

content/uploads/2019/01/CPFS6-web.pdf. (September 2019).

Cornwell, E. R., S. L. LaBuda, G. H. Groocock, R. G. Getchell, and P. R. Bowser. 2013.

Experimental infection of koi carp with viral hemorrhagic septicemia virus type IVb.

Journal of Aquatic Animal Health 25:36-41.

Daniel, W. M., C. R. Morningstar, and J. Procopio. 2019. Cyprinus rubrofuscus Lacepède, 1803.

U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, Florida.

Available: https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=3294. (September

2019).

Freyhof, J., and M. Kottelat. 2008. Cyprinus carpio. The IUCN Red List of Threatened Species

2008: e.T6181A12559362. Available: http://www.iucnredlist.org/details/6181/0.

(September 2018).

Fricke, R., W. N. Eschmeyer, and R. van der Laan, editors. 2019. Catalog of fishes: genera,

species, references. Available:

http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp.

(September 2019).

Froese, R., and D. Pauly, editors. 2018. Cyprinus rubrofuscus (Lacepède, 1803). FishBase.

Available: https://www.fishbase.de/summary/Cyprinus-rubrofuscus.html. (September

2018).

GBIF Secretariat. 2018. GBIF backbone taxonomy: Cyprinus rubrofuscus, Lacépède, 1803.

Global Biodiversity Information Facility, Copenhagen. Available:

https://www.gbif.org/species/2367196. (September 2018).

Goodwin, A. E. 2002. First report of spring viremia of carp virus (SVCV) in North

America. Journal of Aquatic Animal Health 14(3):161-164.

Hanchet, S. 1990. The effects of koi carp on New Zealand’s aquatic ecosystems. New Zealand

Freshwater Fisheries Report no. 117. Freshwater Fisheries Centre, MAF Fisheries,

Rotorua, New Zealand.

Huckstorf, V. 2012. Cyprinus rubrofuscus. The IUCN Red List of Threatened Species 2012:

e.T166052A1108337. Available: http://www.iucnredlist.org/details/166052/0.

(September 2019).

ITIS (Integrated Taxonomic Information System). 2018. Cyprinus rubrofuscus (Lacepède,

1803). Integrated Taxonomic Information System, Reston, Virginia. Available:

https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=688

966#null. (September 2018).

Koi To The World. 2019. Lot Of (15) Assorted 5-8" Koi. Available:

https://www.koitotheworld.com/collections/assorted-koi-lots/products/lot-of-15-assorted-

5-8-koi-5. (September 2019).

Magalhães, A. L. B., and C. M. Jacobi. 2013a. Asian aquarium fishes in a Neotropical

biodiversity hotspot: impeding establishment, spread and impacts. Biological Invasions

15(10):2157-2163.

Magalhães, A. L. B., and C. M. Jacobi. 2013b. Invasion risks posed by ornamental freshwater

fish trade to southeastern Brazilian rivers. Neotropical Ichthyology 11(2):433-441.

Naseka, A. M., and N. G. Bogutskaya. 2004. Contribution to taxonomy and nomenclature of

freshwater fishes of the Amur drainage area and the Far East (Pisces, Osteichthyes).

Zoosystematica Rossica 12(2):279-290.

OIE. 2019. OIE-Listed diseases, infections and infestations in force in 2019. World Organisation

for Animal Health. Available: http://www.oie.int/animal-health-in-the-world/oie-listed-

diseases-2019/. (September 2019).

Rowe, D. K. 2007. Exotic fish introductions and the decline of water clarity in small North

Island, New Zealand lakes: a multi-species problem. Hydrobiologia 583:345-358.

Sanders, S., C. Castiglione, and M. Hoff. 2018. Risk assessment mapping program: RAMP,

version 3.1. U.S. Fish and Wildlife Service.

The University of Waikato. 2019. An introduced species – koi carp. Science Learning Hub -

Pokapū Akoranga Pūtaiao, The University of Waikato - Te Whare Wānanga o Waikato,

Hamilton, New Zealand. Available: https://www.sciencelearn.org.nz/resources/1299-an-

introduced-species-koi-carp. (September 2019).

Yang, B., X. Chen, and J. Yang. 2011. Non-native carp of the genus Cyprinus in Lake Xingyun,

China, as revealed by morphology and mitochondrial DNA analysis. Biological Invasions

13:105-114.

10 References Quoted But Not Accessed

Note: The following references are cited within quoted text within this ERSS, but were not

accessed for its preparation. They are included here to provide the reader with more

information.

Bogutskaya, N.G., A.M. Naseka, S.V. Shedko, E.D. Vasil'eva and I.A. Chereshnev, 2008. The

fishes of the Amur River: updated check-list and zoogeography. Ichthyological

Exploration of Freshwaters 19(4):301-366.

Chen, H.-L. and H.-Q. Huang. 1977. Cyprininae. Pages 395-438 in X. Wu, editor. The cyprinid

fishes of China. Science Press, Peking, China. (In Chinese.)

Dong, C., J. Xu, B. Wang, J. Feng, Z. Jeney, X. Sun, and P. Xu. 2015. Phylogeny and evolution

of multiple common carp (Cyprinus carpio L.) populations clarified by phylogenetic

analysis based on complete mitochondrial genomes. Marine Biotechnology 17(5):565-

575.

Eschmeyer, W. N. 1998. Catalog of fishes. 3 volumes. San Francisco.

Gross, R., K. Kohlmann, and P. Kersten. 2002. PCR–RFLP analysis of the mitochondrial ND-

3r4 and ND-5r6 gene polymorphisms in the European and East Asian subspecies of

common carp (Cyprinus carpio L.). Aquaculture 204:507-516.

Kim, S. W., J. W. Jun, S. S. Giri, C. Chi, S. Yun, H. J. Kim, S. G. Kim, J. W. Kang, and S. C.

Park. 2017. First report of carp oedema virus infection of koi (Cyprinus carpio

haematopterus) in the Republic of Korea. Transboundary and Emerging Diseases 00:1-6.

Kohlman, K., and P. Kersten. 1999. Genetic variability of German and foreign common carp

(Cyprinus carpio L.) populations. Aquaculture 173:435-445.

Kottelat, M. 1997. European freshwater fishes. An heuristic checklist of the freshwater fishes of

Europe (exclusive of former USSR), with an introduction for non-systematists and

comments on nomenclature and conservation.

Kottelat, M. 2001a. Fishes of Laos. WHT Publications Ltd, Colombo 5, Sri Lanka.

Kottelat, M. 2001b. Freshwater fishes of Northern Vietnam: a preliminary check-list of the fishes

known or expected to occur in northern Vietnam with comments on systematics and

nomenclature. The World Bank.

Kottelat, M. 2006. Fishes of Mongolia - A checklist of the fishes known to occur in Mongolia

with comments on systematics and nomenclature. Environment and Social Development

Sector, East Asia and Pacific Region, The World Bank, Washington.

Kottelat, M., and J. Freyhof. 2007. Handbook of European freshwater fishes. Publications

Kottelat, Cornol, Switzerland.

Matsui, K., M. Honjo, Y. Kohmatsu, K. Uchii, R. Yonekura, and Z. Kawabata. 2008. Detection

and significance of koi herpesvirus (KHV) in freshwater environments. Freshwater

Biology 53:1262-1272.

McDowall, R. M. 1979. Exotic fishes in New Zealand - dangers of illegal releases. New Zealand

Ministry of Agriculture and Fisheries Information Leaflet no. 9.

Nelson, J. S. 1984. Fishes of the world. 2nd Edition. John Wiley & Sons, New York.

Pullan, S. 1982. Eradication of koi carp proves difficult. Freshwater Catch 15:24.

Pullan, S. G. 1984. Koi in the Waikato River system. Internal report, New Zealand Ministry of

Agriculture and Fisheries, Auckland, New Zealand.

Smithsonian National Zoo and Conservation Biology Institute. 2019. Japanese koi. Available:

https://nationalzoo.si.edu/animals/japanese-koi.

Tempero, G. W., N. Ling, B. J. Hicks, and M. W. Osborne. 2006. Age composition, growth, and

reproduction of koi carp (Cyprinus carpio) in the lower Waikato region, New Zealand.

New Zealand Journal of Marine and Freshwater Research 40: 571-583.

Tomelleri, J., and M. Eberle. 1990. Fishes of the Central United States. University Press of

Kansas, Lawrence, Kansas.

USDA (U.S. Department of Agriculture). 2006. Census of aquaculture (2005), volume 3, special

studies, part 2. USDA, National Agricultural Statistics Service, AC-02-SP-2,Washington,

D.C. Available: www.agcensus.usda.gov/.

Vieira, F. 2010. Distribuição, impactos ambientais e conservação da fauna de peixes da bacia do

rio Doce. MG.BIOTA 2:5-22.

Zhou, J., Q. Wu, Y. Ye, and J. Tong. 2003a. Genetic divergence between Cyprinus carpio carpio

and Cyprinus carpio haematopterus as assessed by mitochondrial DNA analysis, with

emphasis on origin of European domestic carp. Genetica 119:93-97.

Zhou, J., Z. Wang, Y. Ye, and Q. Wu. 2003b. PCR-RFLP analysis of mitochondrial DNA ND5/6

region among 3 subspecies of common carp (Cyprinus carpio L.) and its application to

genetic discrimination of subspecies. Chinese Science Bulletin 48(5):465-468.

Zhou, J., Q. Wu, Z. Wang, and Y. Ye. 2004. Molecular phylogenetics of three subspecies of

Common Carp Cyprinus carpio, based on sequence analysis of cytochrome b and control

region of mtDNA. Journal of Zoological Systematics and Evolutionary Research

42(4):266-269.

Zhu, S.-Q. 1995. The synopsis of freshwater fishes of China. Jiangsu Science and Technology

Publishing House, Nanjing, China. (In Chinese, English summary.)

Zoran et al. 2017. [Source material did not give full citation for this reference].