Scardinius erythrophthalmus




Type Locality

Northern Europe (Linnaeus 1758)


Etymology/Derivation of Scientific Name

Scardinius erythrophthalmus: scar - Greek, meaning “a kind of fish”; din - Greek, meaning “terrible, whirling”; erythro – Greek, meaning “red”; phthalm, Greek, meaning “the eye”.



Rutilus rutilus (Linnaeus 1758)



Maximum size:  400 mm SL (Hensley and Courtenay 1980).


Coloration: Eyes and fins usually red (Hubbs et al. 1991). Bright red anal, pelvic, and pectoral fins bright red on the extremities (Muus and Dahlstrom 1971). Red-brown caudal and dorsal fins. Brown-green above, brassy yellow side; gold eye with red spot at top (Page and Burr 1991).


Teeth count: 3, 5-5, 3 or 2,5-5,2; without prominent parallel grooves (Hubbs et al. 1991).


Counts: Fewer than 10 soft rays on dorsal fin (Hubbs et al. 1991). 36-45 lateral scales; 10-11 anal rays (Page and Burr 1991).


Body shape:  Deep, compressed body (Page and Burr 1991).


Mouth position: Terminal, oblique mouth (Page and Burr 1991).


External morphology: Abdomen behind pelvic fins scaled; gill rakers short and stout, nine to 10 on first gill arch. Lateral line greatly decurved. Premaxillaries protractile; upper lip separated from skin of snout by a deep groove continuous across the midline. Cartilaginous ridge of lower jaw hardly evident and not separated by a definite groove from the lower lip. Distance from origin of anal fin to end of caudal peduncle contained two and one-half or fewer times in distance from tip of snout to origin of anal fin (Hubbs et al.1991). Small head (Page and Burr 1991).


Distribution (Native and Introduced)

U.S. distribution: Native to Europe, this species originally was introduced into New York and recently has spread throughout the southeast as a bait minnow (Hubbs et al. 1991). By 1991, species widely distributed in southeastern Kansas, and specimens were reported from natural waters in Illinois, Oklahoma, and Texas (Pflieger 1997).


Texas distribution: This introduced freshwater species has been found in Texas in widely scattered localities throughout the state (Hubbs et al. 1991). Specimens have been collected in Lake Teoma (Red River drainage), Grayson Co.; Victor Braunig Reservoir (Guadalupe River drainage), Bexar Co.; Calaveras Reservoir (Guadalupe River drainage), Bexar Co.; Lake Whitney (Brazos River drainage), Hill Co. (Howells et al. 1991); and Canyon Lake, Comal Co., in the Potters Creek Park area of the reservoir (Whiteside and Berkhouse 1992).


Abundance/Conservation status (Federal, State, NGO)



Habitat Associations

Macrohabitat: Lakes and sluggish pools of medium to large rivers (Page and Burr 1991). Pools and backwaters of streams and shallow margins of lakes and ponds (Pflieger 1997).


Mesohabitat: Often associated with dense growths of submerged aquatic vegetation (Pflieger 1997).



Spawning season: In native range, it spawns from April to August (Pflieger 1997).


Spawning location: Adhesive eggs are laid in submerged vegetation in shallow water near shore (Hensley and Courtenay 1980).


Reproductive strategy: Males defend territories during the breeding period, including the plants on which the adhesive eggs are deposited. Males continue to discharge sperm for some time after the eggs have been deposited (Breder and Rosen 1966).


Fecundity: Prolific; single female may produce over 200,000 eggs (Pflieger 1997).


Age at maturation:  Reaches sexual maturity at 2 or 3 years (Pflieger 1997).




Longevity: Maximum lifespan may be 17 years (Pflieger 1997).


Food habits: In native range adults feed mainly on surface or aerial insects; young feed mainly on diatoms, algae, and copepods (Hensley and Courtenay 1980). Omnivorous, feeding on zooplankton, aquatic insects, filamentous algae, higher aquatic plants, and occasionally on fish eggs or small fish (Pflieger 1997).


Growth: Averages 20-30 cm and 200-400 g in approximately 10 years (Muus and Dahlstrom 1971).


Phylogeny and morphologically similar fishes

Golden shiner, Notemigonus crysoleucas, lacks red on fins (young may have light red-orange median fins); has scaleless keel; has usually 7-9 dorsal rays, 11-14 anal rays, 17-19 rakers on first gill arch; pharyngeal teeth 0,5-5,0 (Page and Burr 1991), and no red spot on iris of eye (Crossman et al. 1992). The Rudd is known to hybridize with the Golden Shiner (Burkhead and Williams 1991); hybrid is apparently first known nonsalmonid intergeneric cross of a North American native and an exotic (Taylor et al. 1994).


Host Records

Eimeria pigra n. sp., a coccidian (Leger and Bory 1932). Grodactylus carassii, G. cyprini, G. gasterostei, G. laevis, G. leucisci, G. magnificus, G. prostate, G. vimbi (Harris et al. 2004).


Commercial or Environmental Importance

Species established in Maine and New York after being introduced in the early 1900’s as an ornamental fish (Pflieger 1997). Beginning in the 1980s, the rudd underwent an explosive anthropogenic dispersal; recent dispersal a result of successful marketing of the rudd as a new, hardy, colorful bait minnow, by the Arkansas fish farming industry; characteristics of the species have made it a popular bait with anglers fishing for striped bass Morone saxatilis (Burkhead and Williams 1991). Potential for establishment and dispersal in Southeastern U.S. presently uncertain (Etnier and Starnes 1993). Crossman et al. (1992) suggests the species should not be intentionally or accidentally transferred to other waters, in order to avoid damage to native cyprinid populations by competition and hybridization. Burkhead and Williams (1991) suggest hybridization of the rudd and golden shiner (Notemigonus crysoleucas) may impose a threat to the genetic integrity of the golden shiner.



Breder, C. M., Jr. and Rosen, D. E. 1966. Modes of Reproduction in Fishes. T. F. H. Publications, Jersey City, 941 pp.

Burkhead, N.M., and J. D. Williams. 1991. An intergeneric hybrid of a native minnow, the golden shiner, and an exotic minnow, the rudd. Transactions of the American Fisheries Society 120:781-795.

Cross, F. B. and J. T. Collins. 1995. Fishes in Kansas. University Press of Kansas. Lawrence, Kansas, 315 pp.

Crossman, E. J., E. Holm, R. Cholmondeley, and K. Tuininga. 1992. First record for Canada of the rudd, Scardinius erythrophthalmus, and notes on the introduced round goby, Neogobius melaostomus. Canadian Field-Naturalist 106(2):206-209.

Etnier, D. A., and W. C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press, Knoxville. 681 pp.

Harris, P. D., A. P. Shinn, J. Cable, and T. A. Bakke. 2004. Nominal species of the genus Gyrodactylus von Nordmann 1932 (Monogenea: Gyrodactylidae), with a list of prinicipal host species. Systematic Parasitology 59:1-27.

Hensley, D. A. and W. R. Courtenay, Jr. 1980. Scardinius erythrophthalmus (Linnaeus), Rudd. pp. 360 in D. S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raliegh, i-r+854 pp.

Howells, R. G., R. W. Luebke, B. T. Hysmith, and J. H. Moczygemba. 1991. Field collections of Rudd, Scarinius erythrophthalmus (Cyprinidae), in Texas. Southwestern Naturalist 36:244-245

Hubbs, C., R. J. Edwards and G. P. Garrett. 1991. An annotated checklist of freshwater fishes of Texas, with key to identification of species. Texas Journal of Science, Supplement 43(4):1-56.

Leger, M., and T. Bory. 1932. Eimeria pigra n. sp., nouvelle coccidae juxtaepitheliale, parasite du gardon rouge. Comptes Rendus Hebdornaires des Seances de l’Academie des Sciences 194:1710-1712.

Linnaeus. 1758. Systema naturae, Laurentii Salvii, Holmiae, 10 ed. 1:1-824

Muus, P. J., and P. Dahlstrom. 1971. Collins guide to the freshwater fishes of Britain and Europe. Collins, London. 222 pp.

Page, L. M., and B. M. Burr.  1991.  A Field Guide to Freshwater Fishes of North America, north of Mexico.  Houghton Mifflin Company, Boston, 432 pp.

Pflieger, W. L. 1997.  The Fishes of Missouri. Missouri Department of Conservation, Jefferson City, 372 pp.

Taylor, J. N., W. R. Courtenay, Jr., and J. A. McCann. 1984. Known impacts of exotic fishes in the continental United States. pp. 322-373 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., eds. Distribution, biology, and management of exotic fishes. Johns Hopkins University Press, Baltimore, Maryland.

Whiteside, B. G. and Casey Berkhouse. 1992. Some new collection locations for six fish species. The Texas Journal of Science 44(4):494