Crucian Carp, Golden Carp, Gibele, Prussian Carp, English Carp, Carassius vulgaris (Nilsson, 1840), Cyprinus arassius (Linneaus, 1758)

Dorsal rays iii-iv (14-21); Anal rays ii-iii (5-8); Pharyngeal teeth in one row (0,4-4,0); Gill rakers 22-33; lateral line scales 28-37. Dorsal and anal fins have a serrated, spinelike ray. Typically, individuals are deep-bodied and laterally compressed; however, a slender "shallow-body" variety also exists. The body is golden copper, darker dorsally with reddish fins.  Barbels are not present around the mouth.

Crucian carp are distinguished from Goldfish (Carassius auratus) as follows:

Carassius carassius are relatively inactive fish that inhabit littoral zones and tend to locate themselves within habitat structure, especially in the presence of predators (Holopainen et al. 1997). Crucian Carp thrive in shallow ponds with dense, emergent vegetation such as Typha spp. and Phragmites spp. (Wheeler 2000).

Crucian Carp actively feed during the summer months (Penttinen and Holopainen 1992). While planktonic and benthic invertebrates typically form the dominant part of the diet, Carassius carassius will also feed on phytoplankton plant material, and detritus (Penttinen and Holopainen 1992; Holopainen et al. 1997).

Crucian Carp typically have a lifespan of 10 years with males reaching sexual maturity at 3 years and females at 4 in Central and Eastern Europe (Freyhof and Kottelat 2008).

Crucian Carp spawn intermittently from late spring through mid-summer, after water temperatures have reached the required threshold of 17-20 °C (Holopainen et al. 1997). This species is a phytophilous, open substrate spawner with eggs that adhere to submerged structures and macrophytes (Holopainen et al. 1997). Relative and absolute fecundity varies among populations and environments and increases with size. Average relative fecundity of Crucian Carp in Lake Varaslampi was 129.2 eggs/g of fish, which would amount to an absolute fecundity of 121,822.7 for an average sized female in that lake (942.9 g wet mass) (Holopainen et al. 1997). Fertilized eggs were found to develop normally in laboratory conditions at 15-28 °C, but died at 5, 10, and 30 °C. Temperatures of 24-28 °C resulted in the quickest (>3 days) incubation from fertilization to the free embryo stage. In Scandinavian ponds, hatching took six days at 18-19 °C (Holopainen et al 1997).

Growth rates can be highly variable and are believed to be strongly influenced by population densities and food availability. In their first year of life, Carassius carassius have been observed to range in size from 2.2 to 10.9 cm depending on the population density, environment, and when an individual was born during the spawning season (Skora 1982, Holopainen et al. 1997).

This species occurs regularly in small ponds (often as a monoculture assemblage) as well as in larger lakes with high species richness. Crucian Carp exhibit two distinct morphologies which are reported to be driven predominantly by the fish community assemblage. Particularly, the existence of “pond” and “lake” forms of Crucian Carp are believed to be strongly related to the presence or absence of predators more than environmental or physical characteristics of the water body. In Swedish lakes, Crucian Carp population density and size were significantly smaller (mean size 9.2 cm, 20 g) in ponds and lakes without piscivores than in water bodies with piscivores (mean size 31.3 cm, 735 g) (Bronmark et al. 1995). However, growth-stunted, low-bodied (‘pond’ form) Crucian Carp were observed to shift their deep-bodied form (‘lake’ form) when introduced into a fishless, productive pond. This suggests that two different conditions can induce Crucian Carp to grow into the deep-bodied lake forms: 1) the presence of piscivorous fish and 2) increased food availability in the absence of piscivorous fish (Holopainen et al. 1997).

Potential pathway(s) of introduction: Unauthorized intentional release

Carassius carassius are available from aquarium stores online under several names (e.g., “gold Crucian carp”). There is also a significant potential for misidentification (Tarkan et al. 2010) and sale of Crucian Carp as or with goldfish (Carassius auratus). This species spreads primarily through human release, which has been rapid due to confusing/mistaken taxonomic identification, as well as its common occurrence as a pet in Europe. It has also been identified as one of the top 5 aquaculture species in China by Yang et al. (2021) leading to another potential pathway of unintentional release if it is deliberately used for food.

Carassius carassius can survive in a wide variety of water conditions and are remarkably hardy (Muus and Dahlstrom 1978). This species can survive in waters with temperatures below 0°C, and can even survive for several days with frozen integument (Szczerbowski and Szczerbowski 2002) or burrowed into mud (Holopainen et al. 1997), making them likely candidates for surviving Great Lakes winters.
They are omnivores. Carassius carassius is an open substrate spawner with eggs that adhere to twigs and macrophytes (Holopainen et al. 1997) so they use aquatic weeds for spawning (and egg attachment) (FAO Fisheries and Aquaculture Department 2013). The Great Lakes region has many habitat types that would meet the requirements for C. carassius.

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

C. carassius are viable hosts for the fatal spring viraemia of carp virus. This virus has the potential to affect native cyprinids as well as non-cyprinid species such as Northern Pike (Esox lucius), Largemouth Bass (Micropterus salmoides), and Bluegill Sunfish (Lepomis macrochirus) (Dixon and Stone 2017).  Benthic feeding and disturbance of surface sediment may have an important effect on nutrient cycling and trophic dynamics (Holopainen et al. 1997).

Carassius carassius has the potential for low socio-economic impacts if introduced to the Great Lakes.

Several researchers have found C. carassius bioaccumulates pesticides, PCBs,  fluorinated antibiotics, and microplastics. These things could pose health risks to humans (He et al. 2019, Merga et al. 2020, Sula et al. 2020, Sun et al. 2020, Wei et al. 2023).

Carassius carassius has the potential for high beneficial impact if introduced to the Great Lakes.

Carassius carassius is a superb bait fish, but low value as food in Europe (Holopainen et al. 1997). In China, however, Yang et al. (2021) lists C. carassius as one of the top 5 aquaculture species for food. Its growth rate is very high in eutrophic waters making them potential producers of high quality animal protein for fodder or human food by aquaculture (Holopainen et al. 1997). Also, there is a great potential for laboratory culture and using C. carassius as a model in translational medicine (Gerber 2024). C. carassius also exhibits a wide range of feeding habits that make it a suitable species for routine ecotoxicologial assays (Holopainen et al. 1997).

In Ohio, it is unlawful for any person to possess, import or sell live Carassius carassius and dead specimens must be headless, preserved in ethanol or formaldehyde, or eviscerated. This species is not on the Illinois Aquatic Life Approved Species List and if it is not otherwise native to Illinois it is illegal to be imported or possessed alive without a permit. Possessing, importing, purchasing, selling, propagating, transporting or introducing C. carassius is prohibited in Minnesota. There are no regulations on C. carassius in Ontario, New York, Michigan, Indiana, or Wisconsin.

Control

Biological

In Lake Savijarvi, Finland, stocking of Northern Pike (Esox lucius) was done in conjunction with removal seining to reduce the biomass of Crucian Carp. In three years following the stocking, Crucian Carp biomass decreased from 243 to 136 kg while Northern Pike increased from 0.1 to 5.7 kg per seining hectare. Pike consumption of Crucian Carp was 17% of the removal catch during one year of the study (Lappalainen et al. 2013). The presence of predatory fish in the Great Lakes may limit the proliferation of Carassius carassius if it were to become established.

Physical

Various types of physical controls that have been used to control other non-indigenous fish might also be effective in managing C. carassius. Patrick et al. (1985) observed that air bubble curtains have been successful in deterring Rainbow Smelt (Osmerus mordax), Alewife (Alosa pseudoharengus), and Gizzard Shad (Dorosoma cepedianum)—especially when used in conjunction with strobe lights. Other types of physical treatments have been employed in fish control include reservoir drawdowns, traps, nets, electrofishing, and combinations of these treatments. Through their review of fish control methods, Meronek et al. (1996) observed that projects that utilized nets were the most successful of the previously listed physical treatments.

Chemical

Of the four chemical piscicides registered for use in the United States, rotenone and antimycin have been used in the majority of chemical control projects and have had varied success rates for different species and different bodies of water (Boogaard et al. 1996; GLMRIS 2012; Meronek et al. 1996; Marking et al. 1983).

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

There is some confusion in the literature surrounding the use of the names crucian carp and Prussian carp. Lever (1996) listed Prussian Carp as an alternative or local vernacular name sometimes used for the crucian carp; however, Berg (1964) and most others use the name Prussian carp for Carassius auratus gibelio. In the 1800s Baird witnessed fish taken out of the Hudson River, New York; Baird later wrote that these fish appeared to be "hybrids between goldfish and the Prussian carp" (Redding 1884). In that instance it is not certain as to which species Baird is referring to in using the term Prussian carp. Cole (1905) quoted from one of Baird's reports, in which Prussian carp is treated as synonymous with Cyprinus carassius (=Carassius carassius?).

No known voucher specimens.