The chub is widespread across Europe, but it is not native to Ireland. In fact, they are a very recent introduction to Ireland's fish fauna. In 2005, fisheries staff confirmed anglers’ reports of chub caught in the River Inny. An eradication campaign in the Inny captured 30 chub, but after no sightings for several years, their presence was confirmed once again in 2020.
Chub have a sturdy body, with brassy coloured sides, dark fins, a blunt head and a large mouth. Their scales are distinctively large and dark-edged, and they also can be distinguished by the dorsal fin on their backs and anal fin on their bellies, which both have a rounded, convex edge. Adult chub are a shoaling fish and are voracious predators that will eat almost any prey they can get their mouth around. For this reason, introduced chub threaten native species either by eating them, especially smaller juvenile fish, or by competing with them for food. They prefer to inhabit large lowland rivers with a moderate flow of water but are sometimes found in tributaries or deeper pools in rivers.
Inland Fisheries Ireland is closely monitoring the occurrence of chub as an invasive species in Ireland's rivers. Anglers are asked to report any catches of chub to Inland Fisheries Ireland’s 24-hour hotline number 1890 34 74 24 or 1890 FISH 24 without delay.