An angler has claimed to have caught a one-in-a-million “Frankenstein fish” which appears to be up of three different species.
Mark Sawyer, 53, said he was fishing for carp when he hooked the odd-looking specimen, which he initially thought was a common brown goldfish.
But on closer inspection he found it appeared to have the head of a roach, the body and tail of a brown goldfish and the rear fin of a bream.
Mr Sawyer, who works as the tackle editor for trade magazine the Angling Times, photographed it before throwing it back into Magpie Lake in Cambridge.
He said: “I have shown the picture to a number of marine boffins who say it is definitely the result of mixed parentage.
“I have caught thousands and thousands of fish but have never seen anything like it before. It is a proper oddity.
“The head resembles more of a roach, its lips aren’t quite right. It has the body of a normal goldfish, its anal fin resembles a bream and the tail is of a fan-tailed goldfish.”
Dr Paul Garner, a fisheries ecologist, described the fish as truly one-off and said: “I have never seen one in the UK before. It must be at least a one-in-a-million fish and the odds of actually catching it are even greater than that.
“Fan-tailed goldfish aren’t indigenous to this country and they are not stocked in our fisheries or lakes.
“This means that the parent of this fish would have had to have been released into a fishery, probably by somebody who had it in their garden pond as a pet.
“At some point that fish has mated with a common carp and this hybrid fish in the result.
“The head in more carp but the back end and extended fins and tail belong to fan-tailed goldfish.
“Goldfish and carp and from the same family of fish and it would not be uncommon for them to come together.
“What is very unusual, however, is for a fisherman to catch one of their offspring.”
He added one of its parents is likely to have been a fan-tailed goldfish that had been kept in a garden pond and released into a waterway.
“Fan-tailed goldfish aren’t indigenous to this country and they are not stocked in our fisheries or lakes,” he said.