Home Archived April 13, 2016
Link to USGS home page.
Southeast Ecological Science Center

Leuciscus idus (Linnaeus 1758)

Figure 39. Ide, UF 85165, 113 millimeter SL, from the Danube River, Austria.

Figure 39. Ide, UF 85165, 113 millimeter SL, from the Danube River, Austria.


       The Ide (fig. 39) is a medium-sized fish, typically growing 30-43 cm TL and weighing 680 g (Wheeler, 1978). Maximum size is about 1 m TL and up to 8 kg (Berg, 1964). It has a typical minnow-shaped body that is moderately thick, and older adults have a raised humped back nape. Lateral-line scales number 55-63. The snout is blunt and the mouth is small, terminal, and oblique. Gill rakers are short, widely spaced, and number 10-14 on the first arch. The pharyngeal teeth are conic, smooth (not serrated), and arranged in two rows (usually 3,5-5,3; fig. 40). The dorsal fin is short, with iii (7-10) rays, and usually originates over the posterior part of the pelvic fin base. The anal fin has iii (9-13) rays. Adults are dark on the back and sides above the lateral line. The lower parts of the sides are light or silvery. The fins are red, especially the anal fin and paired fins. Meristics for Ide are given in appendix B.

Figure 40. Pharyngeal teeth (3,5-5,3) of Ide, UF 85165, 113 millimeter SL, from the Danube River, Austria.

Figure 40. Pharyngeal teeth (3,5-5,3) of Ide, UF 85165,
113 millimeter SL, from the Danube River, Austria.

Similar Species

       The Ide is superficially similar to many native North American cyprinids and does not possess a unique characteristic that sets it apart from native species. Thus, the use of regional or state fish guides is important in 113 millimeter SL, from the Danube River, Austria. the identification of the species. Ide can be distinguished from most native North American cyprinids by the following combination of characteristics: pharyngeal teeth 3,5-5,3, no barbels, lateral-line scales 55-63, and usually 8 branched dorsal rays. Ide can be distinguished from other non-native cyprinids by the combination of a short dorsal fin (usually 8 branched dorsal rays) and 55-63 lateral-line scales.


       A golden variety cultured for ornamental garden ponds (“Golden Orfe”) is pale yellow to orange, often with dark patches (Wheeler, 1969).

       Two subspecies are recognized: Leuciscus idus idus and Leuciscus idus oxianus, Turkestan Ide (Banarescu, 1964; Berg, 1964).

       Ide hybridize with other European cyprinids (including Common Carp and Rudd; Schwartz, 1972, 1981). No hybrids with native North American fishes are known.


       In Europe and Asia, Ide matures at 3-5 years and spawns in April or May (Berg, 1964; Wheeler, 1969; Cala, 1976). In a Swedish study, Ide matured between 31.5 and 43.1 cm TL, with males reaching maturity at a size about 3 cm smaller than that of females (Cala, 1971). In Romania, the Ide attains sexual maturity at lengths of 22.5-33 cm and an age of 3 years (Banarescu, 1964). In contrast, Ide inhabiting a reservoir in a more northern location (Finnish Lapland) reached maturity at a larger size and older age (6-7 years) (Mutenia, 1978). Ide spawns in weedy or sandy shallow areas where the adhesive eggs attach to stones or vegetation (Wheeler, 1969; Cala, 1970). Spawning begins in the spring once the water reaches a temperature of about 5 °C for 2-3 days (Cala, 1970). Wieser (1991) reported that spawning begins when water is about 7-14 °C. Fecundity ranged from 39,000-114,000 eggs (average 88,000) in the Dnieper (Berg, 1964), from 15,000-125,280 eggs in Romania (Banarescu, 1964) and from 42,279-263,412 eggs in Sweden (Cala, 1971). Fecundity increases linearly with fish mass (Cala, 1971). Eggs hatch in about 5 days at 18.5-22 °C, but incubation time increases in cooler temperatures (Cala, 1970; Florez, 1972a). Optimal temperature for embryonic development is 12-18 °C (Wieser, 1991).


       The Ide typically grows to 30-43 cm TL and 680 g (Wheeler, 1978); however, individuals can reach 1 m TL and up to 8 kg (Berg, 1964). Typical habitat includes pools and slow-flowing or still waters; however, deeper waters are sometimes used in winter (Wheeler, 1969). Page and Burr (1991) reported the species from clear pools of medium to large rivers as well as ponds and lakes. Wheeler (1978) noted that the Ide inhabits the lower reaches of large rivers, lowland lakes, and brackish estuaries of rivers, adding that it schools in clean, deep water, moving into shallow freshwater to spawn in the spring. Zhadin and Gerd (1963) reported it was one of the most common fishes in reservoirs on the Ob, Novosibirsk, and Bukhtarma-Zaisan rivers of the former Soviet Union. Seeley (1886) reported that the species is not confined to freshwaters, and is found in the Baltic Sea. Cala’s (1970) study of the River Kvlingen in Sweden reported Ide spent the first year of life in the river, and then joined older fish migrating to the Baltic Sea during the summer months. The species returned to the river in the autumn and remained near the mouth and in the lower reaches throughout the winter (Cala 1970). After spawning in the spring, Ide returned to coastal waters (Cala 1970). Specimens in the River Kavlingean were found to be as old as 14 years.

       Laboratory studies showed that mortality of larvae and juveniles was significant at oxygen concentrations <2 mg/L (Florez, 1972b). Cala (1970) noted that fish kills have been noted since 1910 in River Kavlingean, Sweden, as a result of low oxygen content, high temperatures, and pollution. Upper lethal temperature of larvae and juveniles acclimated to 6-22 °C, varied from 24-29 °C, and was lower in fish acclimated to lower water temperatures (Florez, 1972a).

       Ide feeds on insect larvae and adults, cladocerans, worms, spawn of other fishes, small mollusks, diatoms, and filamentous algae (Zhadin and Gerd, 1963; Berg, 1964; Wheeler, 1969, 1978; Mutenia, 1978). Other dietary items include macrophytes, detritus, and small fishes (Zhadin and Gerd, 1963; Lammens and Hoogenboezem, 1991). In Sweden, small (10-80 mm TL) Ide ate cladocerans and copepods, but Ide >140 mm ate plants, isopods, oligochaetes, and insects (Cala, 1970).

Native Distribution

       The Ide is native to most of Europe and Western Asia (see Berg, 1964 for details).

U.S. Introductions

       The Ide was first imported to the U.S. in 1877 and was cultured by the U.S. Fish Commission and subsequently distributed to several state agencies and individuals (Fuller and others, 1999). Escapes from commercial and government ponds (especially during flooding) have expanded its range in the U.S. The species has been recorded from at least 22 states, but documentation of its true status in the U.S. is poor and often contradictory (Fuller and others, 1999). The states where the Ide is reported from open waters include those that received shipments from the U.S. Fish Commission during the late 1800s.

       There have been reports of localized, reproducing populations in a few areas, but it is uncertain whether any still persist. A reproducing population was discovered in a small pond in the Connecticut River drainage of Connecticut in the early 1960s, but by the mid-1980s that population was reportedly eradicated (Whitworth, 1996; Fuller and others, 1999). Similarly, a reproducing population of Ide in a private pond in Maine was eradicated. Different domesticated forms, (for example, “Golden Orfe”) are occasionally kept in garden ponds, sometimes in combination with Goldfish and Koi. Golden Orfe is also present in commercial aquaculture facilities in California (Dill and Cordone, 1997).

Leuciscus idus
Plate 8. Distribution of Ide in the United States. - click to enlarge

Plate 8. Distribution of Ide in the United States. See Methods for details regarding data used to create
maps, definitions of “eradicated” and “reported” and shading of HUCs and states.

next / back / table of contents / SESC Homepage / Ecophysiology of Non-Native Fishes

FirstGov button  Take Pride in America button