Chester Zoo hopes to dispel myth that piranhas are vicious

Piranhas prefer scavenging for food to hunting

Aquarists at Chester Zoo have begun caring for piranhas for the first time in more than 30 years.

Fish specialists said they hope the arrival of 40 piranhas from South America will allow them to dispel myths about the fish's fearsome stereotype.

Piranhas have a reputation for viciously attacking unsuspecting prey. But experts said they prefer scavenging over hunting.

They also play a key role in stabilising underwater ecosystems.

The aquarium team manager, Hannah Thomas, said piranhas were "very much misunderstood".

Piranhas play a key role in sustaining stable underwater ecosystems

"They are meat-eaters with sharp teeth that sometimes nip the fins and tails of other fish," she said.

"But a good portion of their diet comes from hoovering up bits of dead flesh and dead fish found in rivers, as well as insects and various plant materials."

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She said they played an important role in maintaining the balance of aquatic ecosystems and that without them other species would be unable to thrive.

"Red-bellied piranhas can often be seen swimming in shoals. But this has little to do with co-ordinated hunting and a lot more to do with self-defence," she explained.

"Piranhas often fall victim to larger fish, birds, caimans - which are a member of the alligator family - and Amazon-river dolphins. So, like many animals, they huddle together for protection."