Monster catfish are becoming a growing problem in Germany's lakes and rivers. One such fish in the Isen River in Upper Bavaria is claimed to be 2.5m/9' long and has reportedly even started taking prey as large as swans.
Fishermen say that the giant Wels catfish — which have no natural predators — are turning cannibal and eating one another as they empty the lakes of other fish.
Manfred Holzner, head of the local angling association said: "It is a worrying turn that they are now eating members of their own species and shows how bad things have become."
Ducks haven't been safe on the water for some time, but one man reported seeing a swan just 'disappear' as it was apparently pulled down below the surface by one of the fish.
Swimmers have been bitten by large catfish in the past — in 2008 there was a spate of attacks on swimmers in Berlin's Lake Schlachtensee. A schoolgirl was left with a 17.5cm/7" wound while another victim was bitten on his calf.
Controlling the numbers of the fish is problematical as they are notoriously difficult to catch, and nets are generally outlawed in the affected waters.
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