July 1
London - Despite their fearsome reputation, piranhas are wimps that gather in large shoals to protect themselves from predators, scientists said on Monday.

Rather than aggressive killers, research shows piranhas are omnivorous scavengers, eating mainly fish, plants and insects, Anne Magurran of Scotland's University of St Andrews said.

Previously it was thought piranhas shoaled as it enabled them to form a cooperative hunting group. However, we have found that it is primarily a defensive behavior.

Piranhas face constant attack from predators including river dolphins, caiman -- a relative of the crocodile -- and bigger fish, such as the giant piracucu.

"Their cautious behavior is crucial to avoid being eaten," she said.

Her work in Brazil shows how shoal sizes increase in relation to predation risk, especially when water levels in the Amazon basin are low, giving piranhas less room to escape attack.
go

Hmmmm..... THink I will give skinny dipping a miss all the same....

When I was a little kid, the first time I heard about Piranhas and what they could do, I became fascinated. However, it was many years before I saw one in an Aquarium Centre and I was totally surprised at just how small they were - mind you they are evil, vicious looking blighters lol.

They remind me of a mob, ready to pounce on the first unsuspecting victim - I think I should like one of them on my BBQ (the piranha not the swimmer)

Ya, they're not as vicious as people make them out to be. I know a guy who kept them as pets in a 750 US gal tank. Granted they were feed red meat and not fish flakes, but... anyway. I have even seen them sold in pet stores ocassionally, but it's more common to see thier larger cousin, the pacu, being sold. Pacus are mostly herbivorous, but they have a nasty bite!

And because they were sold in pet stores and people got tired of keeping them and turn them loose we now have them in Florida. They a baned in Florida.

http://myfwc.com/Fishing/news-rel/nrev-ali.html

I've always wondered why the cow was the standard example on nature shows of how fast piranha can skeletalize an animal. Gary Larson, the creator of "Far Side", asked that once and the question has bothered me ever since.

I agree with Roj, I'm still not gonna be swimming in the Amazon any time soon.

My husband had two of them and one day while he was cleaning the tank one of them took a pretty big chunk out of his thumb, I was pregnant at the time and had horrible visions of our baby puting his or her hand in the tank and getting a finger chomped off so i made him give them away! but they were fun to watch , specially at feeding time!

Yes...... i totally agree. Not sure if i trust those scientists lol i wont be testing their theory.....

Yes they are wild animals, but I hear if you breed them right, they won't bite.

Like we heard this before.

They dont really have to be called "cowards", this animals just use teamwork to protect them selfs and and hunt. Many animals in the animal kingdom use this strategy especially herbivores., and it actually works. Predators usually get confused when hunting such a big group and others mostly get scared. That is the buffalo's strategy, when one of them is being hunted by lions they team up the whole herd and fight back the lions who usually end up outnumbered. In a herd of buffalos there can be more that 100 buffalos. The Zabras use this strategy to confuse the predators when in a large group, that is one of the usages of their stripes, this stripes confuse the predators due to them being in large numbers and the color of the landscape.

Animals look for many ways to survive in the wild and they are real true survivors, surviving in the african savanah and the tropical forests isn't easy you know.

They are predatory shoal fish. In a shoal they can be very dangerous, but in ones or twos they are as placid as any other species of shoaling fish.

All the hype came from Hollywood exploiting old stories of the fish and some eating habits.