Scardinius erythrophthalmus
(Linnaeus, 1758)
Common Name:
Rudd
Synonyms and Other Names:
Notemigonus crysoleucas roseus (Bean, 1903), Pearl Roach
Identification:
The Rudd is a somewhat stocky, deep-bodied fish with a forked tail, and the mouth is distinct with a steeply angled protruding lower lip. The scales are robustly marked, the back is dark greenish-brown, and the sides are brassy yellow tapering to a whitish belly. The pectoral, pelvic, and anal fins are bright reddish-orange, and the dorsal and tail fins are reddish-brown (PA Sea Grant 2013). Berg (1949); Maitland (1977); Muus and Dahlstrom (1978); Wheeler (1978); Smith (1985); Burkhead and Williams (1991); Page and Burr (1991); Crossman et al. (1992); Pflieger (1997). Burkhead and Williams (1991) provided diagnostic characters for the recognition of Rudd x Golden Shiner crosses. Rudd can be distinguished from all native North American minnows (Cyprinidae) by the presense of a scaled keel along the belly between the pelvic and anal fins, along with a deep compressed body. Rudd is superficially similar to the native Golden Shiner (Notemigonus crysoleucas), and can be distinguished by the following characters (Howells 1990; Page and Burr 2011)
| | Rudd | Golden Shiner |
| Dorsal fin rays | 9-11 | 7-9 |
| Anal fin rays | 10-11 | 8-19
(usually 11-14) |
| Gill rakers on 1st arch | 10-13 | 17-19 |
| Pharyngeal teeth | 3,5-5,3 | 0,5-5,0 |
| Lateral line scales | 36-45 | 44-54 |
| Ventral keel | Scaled | Unscaled |
| Eyes | Red or gold with red spot | Yellow-green |
| Fin color | Bright red | Yellow-green
(except in spawning adults
and southern population) |
Size:
Maximum total length of 61.7 cm (Sprem et al. 2010).
Native Range:
Western Europe to the Caspian and Aral sea basins (Berg 1949; Robins et al. 1991).
Great Lakes Nonindigenous Occurrences:
The first recorded Rudd specimen in the Great Lakes was in 1989 in Thompsons Bay, Lake Ontario (Crossman et al. 1992). However, due to introductions of Rudd to the Finger Lakes region in New York in the 1930s, Sturtevant et al. (2019) estimated that Rudd first entered the Lake Ontario basin as early as 1931. Rudd later spread to Lake Erie in 1993 (OFAH 2010) and was found in Sawyer Harbor of Lake Michigan in 1994 (WDNR 2014).
Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Scardinius erythrophthalmus are found here.
Full list of USGS occurrences
Table last updated 4/19/2024
† Populations may not be currently present.
* HUCs are not listed for areas where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).
Ecology:
Rudd is a benthic cyprinid fish that prefers water up to 3 meters deep and temperatures between 2 and 22°C (Gerstmeier and Romig 1998; Glinska-Lewczuk et al. 2016; Juza et al. 2018). Abundance decreases with depth, and Rudd populations benefit from artificial and natural coastal refuges that help them avoid predation (Lemmens et al. 2016; Virbickas and Stakenas 2016). Rudd were previously described as a littoral species that prefers lentic habitats (Johansson 1987; Lake et al. 2002), however, recent studies of Rudd populations in the Niagara River found higher abundance, growth, and reproductive success in lotic versus lentic habitats (Kapuscinski et al. 2012a).
Rudd has omnivorous feeding habits that can change with temperature and season. Generally, their diet includes macrophytes, bryophytes, and filamentous algae along with fish and some other animal material and detritus (Nurmien et al. 2003; Guinan et al. 2015). Rudd in Lake Banyoles, an oligotrophic, karstic lake was more zooplanktivorous in spring and autumn and less in summer and showed a size-dependent diet shift from microcrustaceans while small, to macroinvertebrates at larger sizes (Garcia-Berthou and Moreno-Amich 2000). Guinan et al. (2015) showed Rudd in the upper Niagara River exhibited a diet switch from piscivory in early spring towards herbivory in summer/fall coinciding with increased macrophyte abundance and warmer water temperatures. The shift from piscivory to herbivory typically occurs once temperatures exceeded ~16°C, allowing Rudd to avoid competition with other fishes or to avoid predation by piscivorous fishes (Johansson 1987; Eklöv and Hamrin 1989; Kapuscinksi et al. 2012a). Another reason for a shift in diet at higher temperatures is that cellulase efficacy was reduced at temperatures greater than 15°C (Vejrikova et al. 2016). Feeding intensity of Rudd was also positively correlated with water temperature (Kapuscinski et al. 2012a)
Reproduction occurs from April to August, typically beginning once water temperatures exceed 16°C (Domagala et al. 2020). Adhesive eggs are laid among submerged vegetation in warmer, calmer, waters near shore. Fecundity ranges from 3,500–232,000 eggs. In the upper Niagara River, the presence of age-0 Rudd was greater in lotic sites and poorer in ones without measurable flow, suggesting reproduction can be successful in lotic habitats (Kapuscinski et al. 2012a). Maturation occurs at 2 to 3 years when the fish is 90 to 150 mm in total length. Maximum life span can reach 17 years (Pfleiger 1997).
Rudd are consumed by various predatory fish, including Pike (Esox lucius), Pike-Perch (Sander lucoperca), and Wels Catfish (Silurus glanis) (Gurbik et al. 2015; Djait et al. 2019). Rudd have similar energy density to other Great Lakes fishes and may be a useful food source (Forzono et al. 2017).
Means of Introduction:
Bait bucket release seems to be the primary mechanism by which Rudd have gained access into open waters. However, the history of its introduction is complex and only partly known. The species apparently entered the United States during two widely separated periods of introduction. It was initially brought to this country either in the late 1800s or early 1900s. A second period of introduction presumably began in the late 1960s or early 1970s. The first verifiable U.S. record dates to 1916. In that year, some 300 specimens were obtained from the New York aquarium by B. O. Webster, the Wisconsin superintendent of fisheries, were transplanted to Lake Oconomowoc, Wisconsin (Cahn 1927; Greene 1935). Myers (1925) reported on a population in Central Park Lake in New York City. The Central Park population, now extirpated, may have originated from Copake Lake, Roeliff-Jansen Kill system, which also supported a population in 1916 and possibly earlier (M. N. Feinberg, personal communication to Burkhead). The origin of the very first New York fish is not known; however, because Rudd is popular in Europe as a food and game species, it may have been introduced for both purposes. The Central Park population also may have been the source for the transplant to a New Jersey park just across the Hudson (Myers 1925; Greeley 1935).
The early 1950s capture of Rudd by C. R. Robins in Cascadilla Creek, Tompkins County, New York, appears to be the only and last known record from the creek (Courtenay et al. 1984; Smith 1985). The origin of this population is not documented, but the relatively close Roeliff-Jansen Kill population is a logical possibility. The earliest of the more recent records is a 1973 capture of Rudd from Cobbosseecontee Lake in Maine. Neither year nor origin of the Maine introduction is known. At about the same time, a bait dealer in Suffolk, Virginia, began rearing Rudd for bait. The source of the Suffolk, Virginia fish farmer's stock is uncertain. The interest in bait culture of Rudd dramatically intensified in the early 1980s. The central Arkansas region of Lonoke and Prairie counties, an area known for its active fish farming industry, apparently became the largest producer of Rudd in the United States. It appears that the greatest dispersal of Rudd has been through interstate traffic rather than direct European import. In fact, much of its recent culture and spread can be attributed to its popularity as a bait among Striped Bass Morone saxatilis anglers. As a result, Rudd have been widely introduced through a combination of bait bucket releases, escapes from aquaculture facilities and farm ponds, and, presumably, by dispersal from various points of introduction (e.g., Burkhead and Williams 1991). Although many Rudd introductions are considered accidental, it is likely that Rudd also have been intentionally released into public waters during the past few decades.
Status:
This species has been recorded as introduced to 23 US states and the Canadian province of Ontario. In a number of other states it has been used as a bait fish, but there is as yet no record of it being found in open waters. Available data indicate established populations still survive in Maine and New York, and, more recently, evidence indicates it is established in Massachusetts, Nebraska, and South Dakota. The species had breeding populations in New Jersey, Wisconsin, and Kansas, but it is apparently no longer extant in these states. It has been established in Lake Cobbosseecontee, Maine, since 1973 (Courtenay et al. 1984; Burkhead and Williams 1991; Kircheis 1994). It has been established in the Roeliff-Jansen Kill drainage, New York, since the first half of the 1900s (Smith 1985). Probably in reference to that region, Schmidt (1986) listed Rudd as present in the Hudson River drainage in the northern Appalachian region. Other New York populations are considered extirpated (Courtenay et al. 1984; Smith 1985); however, Mills et al. (1993) stated that an established population was discovered in Oneida Lake, New York, in the Lake Ontario drainage, in 1990. It may also be established in the St. Lawrence River and Lake Ontario, but that conclusion awaits confirmation. Hartel et al. (1996) stated that the presence of both young and adults over several years indicated that it is reproducing in the lower Charles River in Massachusetts. According to Zadina (personal communication), Rudd is considered to be established in one or more lakes in Nebraska as of 1998. Presumably this includes Lake Ogallala. There also is evidence of Rudd reproduction in parts of western South Dakota; during the summer of 1997 several year classes were discovered in Pactola Reservoir, Sheraton Lake, and Newall Lake (Unkenholz, personal communication). The species was established and later became extirpated in New Jersey and Wisconsin, however, it is still considered rare in Oconomowoc Lake, WI (Becker 1983; Courtenay et al. 1984; Courtenay and Williams 1992; Kapuscinski et al. 2012b). There has been at least one established population in Kansas. In Spring 1996, a large breeding population was discovered in a 0.6-acre farm pond in the Deep Creek-Kansas River drainage near Manhattan, Riley County. However, that population was exterminated by Kansas Department of Wildlife and Parks personnel in Summer of 1996; as of early 1998, there has been no record of Rudd in sites downstream of the pond (Bever, personal communication). Although they mapped its distribution in Kansas, Cross and Collins (1995) did not provide information on reproductive status. In general, the past literature on Rudd distribution and status is fragmentary and somewhat contradictory. Courtenay et al. (1986, 1991), Courtenay and Stauffer (1990), and Courtenay and Williams (1992) considered it established in Maine and New York. Similarly, Page and Burr (1991) stated that it was established in Maine and in the lower Hudson River drainage in New York. In a relatively recent work, Courtenay (1993) indicated that the Rudd was established in Maine, New York, Kansas, and presumably Nebraska (postal abbreviation given as NB). Jenkins and Burkhead (1994), citing unpublished information, stated that Rudd had become established in Indiana, New York, and Maine. However, we have found no evidence that the Rudd was ever introduced to Indiana waters. It is likely that the inclusion of Indiana was an error (Burkhead, personal communication). Muoneke (1990) incorrectly cited unpublished information in stating that Rudd apparently had become established in Alabama. In many states, it has been recorded but not known to be reproducing. For instance, Jenkins and Burkhead (1994) stated that it is unknown whether escapees have established a population in Virginia. Although it has been reported from several reservoirs in Missouri, Pflieger (1997) stated there is no evidence yet that Rudd is established in the state. Although we have a relatively recent report of this species from Connecticut (Jones, personal communication); Whitworth (1996) stated that the species has not been found in that state. Biologists in Arkansas say it is not established in that state (N. Stone and S. Barkley, pers. comm. 2007).
Great Lakes:
Colonizing, with populations reproducing and overwintering at self-sustaining levels in Lake Erie, Lake Ontario, and Lake Michigan.
Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...
| Environmental | Socioeconomic | Beneficial |
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Scardinius erythrophthalmus has a moderate environmental impact in the Great Lakes. Realized:
In a laboratory setting, Burkhead and Williams (1991) demonstrated that Rudd readily hybridizes with native Golden Shiner (Notemigonus crysoleucas), a primary forage species for many native game fishes. Therefore, the probability exists that Rudd introduced to open waters will hybridize with Golden Shiner, with unknown consequences to wild populations of the native species. First-generation hybrids offspring should show heterosis (or hybrid vigor), but the "genetic pollution" in subsequent generations could prove detrimental due to a variety of factors (e.g., spawning behavior, recruitment success, and general loss of fitness) (Burkhead and Williams 1991; Courtenay and Williams 1992). Nevertheless, the interactions of the two species in nature are not known (Burkhead, personal communication).
Rudd was observed to dominate some environments, making up nearly 50% of catch in Buffalo Harbor and the upper Niagara River during 2007–2008 (Kapuscinski et al. 2012b).
Potential:
Cadwallader (1977) reviewed the potential impacts of the Rudd in waters of the North Island of New Zealand. He concluded, in part, that Rudd can be expected to compete for invertebrate food sources with native fishes. In addition, being omnivorous, Rudd can shift its diet to plants, unlike most native fishes allowing Rudd to avoid competition or avoid predation by piscivorous fishes (Johansson 1987; Eklöv and Hamrin 1989; Kapuscinksi et al. 2012a). Because Rudd is fairly hardy, Cadwallader (1977) also indicated that the fish will fare better than many native fishes in waters that are eutrophic or polluted.
Rudd appears able to maintain balance interactions with macrophyte communities in some cases, but it may have contributed to the shift in Hamilton Lake, New Zealand from a macrophyte to phytoplankton community; its main source of food, the macrophyte Egeria, collapsed over time as secchi depth decreased. Rudd persisted even after the decline of Egeria, shifting its diet to other plants (Hicks 2003). The diet of Rudd and experimental results suggest that Rudd is having an impact on the aquatic communities in New Zealand and may prevent the re-establishment of those species consumed by Rudd (de Winton and Champion 1993; Lake et al. 2002). In the Niagara River, Rudd shifted its diet from pelagic fish to littoral macrophytes during summer months which may create a novel pathway of nutrient transfer among different habitat types (Guinan et al. 2015). Rudd’s selective feeding may also threaten habitat and macrophyte restoration projects (Kapuscinski et al. 2014b, 2015).
The fast growth, large size, long life, reproductive habitat flexibility, and omnivorous diet give Rudd potential to be highly invasive in the Great Lakes (Kapuscinski et al. 2012a).
In the effluent impacted Niagara River, antidepressants had a bioaccumulation factor of up to 3000 in Rudd, which was significantly more than in native fishes and could make Rudd an important factor in biomagnification of these potentially harmful chemicals by predators (Arnnok et al. 2017). However, the concentrations of several other contaminants (e.g., PCBs, DDT, pesticides, fungicides) in Rudd was below detection limits or was lower than in native fishes (Kapuscinski et al. 2014a).
Current research on the socio-economic impact of Scardinius erythrophthalmus in the Great Lakes is inadequate to support proper assessment.
Scardinius erythrophthalmus has a moderate beneficial impact in the Great Lakes.
Realized:
Rudd has been shown to be a valuable food source as they have similar energy density to other Great Lakes fishes and are consumed by Pike, Pike-Perch, and Wels Catfish(Gubrik et al. 2015; Forzono et al. 2017; Djait et al. 2019). Rudd has become a popular sportfish in New Zealand (Hicks 2003) and is a popular baitfish in general (Litvak and Mandrak 1993, Marsden and Hauser 2009; see Means of Introduction).
Management:
Regulations (pertaining to the Great Lakes) In Pennsylvania, it is unlawful to possess, import, or introduce Rudd (58 PA Code § 71.6). In Ohio, it is unlawful to possess, import, or sell Rudd (OAC Ch. 1501:31-19). In Michigan, Rudd is a prohibited fish species (MI NREPA 451 § 324.41301). In Indiana, it is unlawful to import, possess, propagate, buy, sell, barter, trade, transfer, loan, or release into public or private waters any adult or recently hatched or juvenile Rudd or their genetic material (312 IAC 9-6-7). In Illinois, Rudd is an injurious species, meaning it shall not be possessed, propagated, bought, sold, bartered or offered to be bought, sold, bartered, transported, traded, transferred or loaned to any other person or institution unless a permit is first obtained from the Department of Natural Resources in accordance with Ill. Admin. Code Ch. 1 § 805.40, except persons engaged in interstate transport for lawful commercial purposes who do not buy, sell, barter, trade, transfer, loan or offer to do so in Illinois (Ill. Admin. Code Ch. 1 § 805). In Wisconsin, Rudd is a prohibited species under Wis. Admin. Code § NR 40.04, meaning that no person may transport, possess, transfer, or introduce Rudd, except as otherwise provided in paragraphs (b) to (h) of Wis. Admin. Code § NR 40.04. In Minnesota, Rudd is a prohibited species, meaning it is unlawful (a misdemeanor) to possess, import, purchase, transport, or introduce except under a permit for disposal, control, research, or education (MN Admin. Rules § 6216.0250). Rudd are regulated in New York under NYS Part 575, and cannot be knowingly introduced into a free living state, but are legal to possess, sell, buy, propagate, and transport. In Quebec, aquarium fish-keeping, production, keeping in captivity, breeding, stocking, transport, sale or purchase of live Rudd is prohibited (Quebec Statutes and Regulations RRW, c C-61.1, r7). The import, possession, transport, and release of live Rudd in Manitoba and Ontario are prohibited under articles 6 to 10 of the Canadian Fisheries Act SOR/2015-121.
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
There are no known biological control methods for this species.
Physical
Fine-mesh monofilament gill nets have been used to control Rudd in three shallow lakes in Waikato, New Zealand, but elimination was not achievable (Neilson et al. 2004). Small, potentially fecund fish in dense littoral vegetation proved challenging to net, presenting a problem for total eradication, but the removal of larger Rudd likely affected breeding success and netting is seen as a highly cost-effective control method with low environmental impact (Neilson et al. 2004; McEwan and Crisp 2019).
Chemical
Of the four chemical piscicides registered for use in the United States, Antimycin-A and Rotenone are considered general piscicides (GLMRIS 2012). Ling (2003) noted that Rotenone has an LC50 of 24.5 µg/L for 1 hr exposure to Rudd at 20°C.
Increasing CO2 concentrations, either by bubbling pressurized gas directly into water or by the addition of sodium bicarbonate (NaHCO3) has been used to sedate fish with minimal residual toxicity, and is a potential method of harvesting fish for removal, though maintaining adequate CO2 concentrations may be difficult in large/natural water bodies (Clearwater et al. 2008). CO2 is approved only for use as an anesthetic for cold, cool, and warm water fishes the US, not for use as euthanasia (Clearwater et al. 2008). Exposure to NaHCO3 concentration of 142–642 mg/L for 5 min. is sufficient to anesthetize most fish (Clearwater et al 2008).
It should be noted that chemical treatment will often lead to non-target kills, and so all options for management of a species should be adequately studied before a decision is made to use piscicides or other chemicals. Potential effects on non-target plants and organisms, including macroinvertebrates and other fishes, should always be deliberately evaluated and analyzed. The effects of combinations of management chemicals and other toxicants, whether intentional or unintentional, should be understood prior to chemical treatment. Other non-selective alterations of water quality, such as reducing dissolved oxygen levels or altering pH, could also have a deleterious impact on native fish, invertebrates, and other fauna or flora, and their potentially harmful effects should therefore be evaluated thoroughly.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
Remarks:
According to Courtenay and Williams (1992) and Gilbert (1998), Rudd first appeared in the United States during the late 1800s. Main support for their conclusion is based on a footnote of Hubbs (1921). In his footnote, reference is made to a brief description by Bean (1897) of a variety of golden shiner Notemigonus crysoleucas from Central Park Lake, New York City, which Hubbs concluded to be, in reality, introduced Scardinius erythrophthalmus. Hubbs' opinion was based on the "permanent vermilion color of the pectorals, ventrals and anal" described by Bean for specimens apparently held in the New York Aquarium. Later, Bean (1903), repeating the same description as in the 1897 paper, elevated the race to a subspecies (i.e., Abramis chrysoleucas roseus). The principal character on which the new form was based was the blood-red pigmentation of the fins (hence the name roseus). In his investigation on the history of Rudd in the United States, Burkhead (personal communication) was unable to locate types for the subspecies, but he did find a single N. crysoleucas, dated 1894, from Central Park Lake which he examined and concluded as typical in every respect. According to Burkhead, the available information does not support or refute Hubbs' comments. Furthermore, since Hubbs' remarks presumably are based solely on Bean's color description, Burkhead concluded that it seems prudent to discard Hubbs' inference.
Courtenay et al. (1986) described the distribution of Rudd in the eastern United States, listing it among the species with declining populations. However, Courtenay et al. (1991) and Burkhead and Williams (1991) reviewed Rudd introductions and documented the more recent and rapid spread of the species as a result of its wide use as a bait fish for Striped Bass. Many states now outlaw the use of Rudd as a live bait. As a result, its rapid spread appears to have slowed. Although there is no evidence that Rudd has been introduced to California, Dill and Cordone (1997) expressed concern that Rudd may find its way into the state as a contaminant in Golden Shiner shipments imported as bait from Arkansas. This species has been cultured in Arkansas and Virginia (and possibly elsewhere) as baitfish and distributed to bait stores in at least 16 states (Courtenay and Williams 1992). Two specimens were taken from the Canadian side of Lake Erie at Crystal Beach (near Port Abino) in June 1997 (A. Dextrase, personal communication). That record is the first report of Rudd from Lake Erie.
Guinan et al. (2015) reported a similar summer trophic position to introduced Common Carp (Cyprinus carpio) and Goldfish (Carassius auratus), and suggested that seasonal trophic flexibility as a potential driver to facilitate both introduction success and the creation of novel nutrient transfer pathways among habitat types.
Voucher specimens: Massachusetts (MCZ 95616, MCZ 96072, MCZ 99432), New York (AMNH 58445, NYSM 25122, 35122, 40871, 41752, 41850), Vermont (NYSM 42040).
References
(click for full reference list)
Author:
Nico, L., P. Fuller, G. Jacobs, J. Larson, T.H. Makled, A. Fusaro, M. Neilson, and A. Bartos
Contributing Agencies:
Revision Date:
8/3/2021
Peer Review Date:
8/3/2021
Citation for this information:
Nico, L., P. Fuller, G. Jacobs, J. Larson, T.H. Makled, A. Fusaro, M. Neilson, and A. Bartos, 2024, Scardinius erythrophthalmus (Linnaeus, 1758): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/greatLakes/FactSheet.aspx?Species_ID=648&Potential=N&Type=0, Revision Date: 8/3/2021, Peer Review Date: 8/3/2021, Access Date: 4/19/2024
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.