Piranha in English river … a real piranha?

From the BBC:

Friday, 28 August 2009

Devon river team’s piranha shock

A “killer” fish native to South America has been found in a Devon river.

The Environment Agency said its staff were amazed to find a dead piranha in the East Okement tributary of the River Torridge.

The piranha, which has razor-sharp teeth, is generally considered to be the most ferocious freshwater fish in the world.

The 35cm (14in) fish was spotted by Bob Collett, Dave Hoskin and Eddie Stevens during a sampling trip on the river.

Among the species the team would have expected to find in the river were salmon, brown trout, bullheads, stone loach and minnow.

“What we actually discovered was something we would not expect to find in our wildest dreams – we could hardly believe our eyes,” Mr Stevens said.

“After completing 20m of the survey, a large tail emerged from the undercut bank on the far side of the river.

“Our first thought was that a sea trout had become lodged in amongst the rocks and debris collected under the bank, but when it was removed from the river we were speechless to find it was a piranha.”

Tests carried out on the dead piranha revealed it had been eating sweet corn, which proved it must have been kept as a pet.

The Environment Agency said the average size of a piranha was 15 to 20cm (6in to 8in), making the fish found on the East Okement an exceptional size.

A shoal of piranha fish is said to be able to strip the flesh of large animals within minutes. They have also been known to attack humans.

In the wild, piranhas are found in the Amazon basin, in the Orinoco and the rivers of the Guyanas.

The Environment Agency said it believed the piranha was alive when it was put in the river, possibly because it had become too big for its tank.

Spokesman Paul Gainey said: “Whilst piranhas can’t survive the colder climates of the UK, this latest find highlights a real issue – that releasing unwanted exotic pets or plants into rivers can have serious consequences for native wildlife.

“Rather than dumping things in the wild, we would urge people to seek advice about what to do with exotic species.”

However, is this really a piranha? Practical Fishkeeping has doubts about that:

However, Practical Fishkeeping believes that the fish in the Agency’s image appears to be a Red-bellied pacu, Piaractus brachypomus, a species that can reach over 80cm and weigh more than 25kg.

This largely herbivorous species was once a common aquarium fish, but the species has become less common as the keeping of larger-growing species has fallen out of favour and many shops have become unwilling to re-home fish purchased by fishkeepers unable to adequately meet their long-term needs.

Talking about a real piranha, though about one who has been dead for far longer than the piranha (or pacu?) in England: Fossil Megapiranha sheds light on evolution of piranha teeth.

Britain: ‘Killer Folkestone piranha’ not piranha at all [but pacu]: here.

This monstrous fish is a tambaqui, a close relative of the piranha. Fortunately, it doesn’t share its cousin’s flesh-eating lifestyle. Instead, the 30-kilogram tambaqui (or pacu) is a vegetarian. It swims through the flooded forests of the Amazon, eating fruits that drop from the overhanging trees. In doing so, it acts as an vehicle for the Amazon’s seeds, carrying them to distant parts of the jungle within its gut: here. And here.

Pacu in Papua New Guinea: here.

Pacu in Denmark: here.

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• Exotic fish caught in lake near Marysville (heraldnet.com)
• The Debunker: Will Piranhas Strip Off Your Flesh? (woot.com)