Review and Meta-Analysis of the Environmental Biology and Potential Invasiveness of a Poorly-Studied Cyprinid, the Ide Leuciscus idus

Abstract The ide Leuciscus idus is a large-bodied cyprinid native to freshwaters around the Baltic, Black, Caspian, White, Barents, Kara, Laptev and North seas as well as the Aral Sea region. Historically an important commercial species, the ide is used in recreational fisheries and as an ornamental fish, and is subject to translocation and stocking events. The ide is less well-studied than many European cyprinids and relatively little is known of the risks it poses to native species and ecosystems where introduced. The present review and meta-analysis examine available data on the ide’s environmental biology to provide an assessment of its potential invasiveness. A long-lived, omnivorous species, the ide is a habitat generalist that inhabits lowland rivers and nutrient-rich lakes, but also some brackish waters where it is facultatively anadromous. The ide displays variable age and length at maturity and asymptotic growth in body length, can be highly productive and migratory, and can withstand variable environmental conditions. Despite several attributes that should facilitate acclimation to novel environments, the ide has established relatively few self-sustaining populations outside its native range, and is therefore not currently considered to be invasive. However, as introductions are likely to continue, increased propagule pressure could lead to the development of invasive non-native populations in some locations.