thumb|250px|Gold orfe

The ide (Leuciscus idus), or orfe, is a species of freshwater ray-finned fish belonging to the family Leuciscidae. The ide is found in larger rivers, ponds, and lakes across Northern Europe and Asia. It has been introduced outside its native range into Europe, North America, and New Zealand. It is a popular ornamental fish, usually kept in outdoor ponds in temperate regions from which it often escapes.

Etymology

The name "ide" is from Swedish id, originally referring to its bright colour (compare the German dialect word Aitel, a kind of bright fish and Old High German Eit, funeral pyre, fire). The alternative name "orfe" derives from German Orf, through the Latin orphus meaning a "sea fish" or "sea perch", which in turn derives from the Greek orphōs. The generic name Leuciscus is derived from the Greek word leykiskos, which means "white mullet".

Subspecies

The two recognised subspecies of the ide are:

The dorsal fin has three spines and 8–11 soft rays, the anal fin has three spines and 8–11 soft rays, while the caudal fin has 19 rays. It has 47 vertebrae. It is distinguished from other European members of the genus Leucsicus by the lateral line having 56–58 scales; 3.5–5.3 pharyngeal teeth, in having a terminal mouth, and branching in 8% of the dorsal rays and 10% of the anal rays. Reports have been made of ides attaining total lengths around 100 cm and weights of 8 kg.

Distribution

The ide is native to Europe and western Asia from the rivers draining into the North Sea east through southern Scandinavia and eastern Europe to the Caspian Sea drainage and the River Lena. and is now widespread in England and Wales, but only has a localised distribution in Scotland. It was introduced into France

The ide was illegally imported into New Zealand <!-- in the post --> as eggs, sometime in the 1980s. Fish were subsequently released between 1985 and 1986 in no less than eight and possibly as many as 13 sites north of Auckland. Ide probably did not last very long in at least seven of the sites where releases occurred, the outcome in most of the other sites is unknown, and at least one of the release sites remains unknown. Ide likely persist in the wild in at least one site within New Zealand.

Habitat and ecology

Ide occur in schools in the clear pools of larger rivers, ponds, and lakes, but they may move to deeper waters during the winter before moving into shallow fresh water to spawn in the spring. The species is also found in the Baltic Sea, which has a lower salinity than most seas, and in Sweden, the fish spend the first year of their lives in rivers before joining the more mature fish as they migrate downstream into the Baltic Sea during the summer. The fish then return to the rivers in the autumn, where they remain close to the mouths and in the lower reaches throughout the winter.

In their native range, they are popular as a quarry for anglers; in eastern Europe, the ide is regarded as edible and is prized as a food fish, and are netted and sold commercially along the Danube. In more northern parts of the range, though, they are not regarded as a desirable food fish. They are also fished for as coarse fish in the United Kingdom, but there they tend to be localised to commercial fisheries or to sites where they have been introduced.

References

Further reading

  • Introductions of ide in the US
  • NIWA June 2006
  • "Coarse fish teara.govt"