Barbel are breeding in the River Clyde, Scotland, threatening the ecosystem that supports a salmon fishery, according to a story in today's Herald.
Barbel (Barbus barbus) are large, omnivorous cyprinids and can reach over 20lb in weight. It is thought that the barbel have been deliberately introduced into the Clyde by anglers, as they are a prized sport fish.
Professor Peter Maitland of the Fish Conservation Centre told The Herald: "It will be easy now for Barbel to be transferred to other rivers in Scotland. The main concern over these fish in the Clyde is that they grow very big, and as bottom feeders, it is likely that they will feed on eggs in the gravel.
"There is also every likelihood that they are competing for space with native species."