Red bellied piranhas

My wife and I recently took a trip on the riverboat MV Amatista from the jungle city of Iquitos upriver on the Amazon to the confluence of the Marañón and Ucayali rivers. Before we left, several friends warned us not to get eaten by the piranhas, the small meat-eating fish with the reputation as a ferocious man-eater. It turns out that we ate piranhas, not the other way around.

Our brochure for the trip promised that, among other river and jungle excursions, we would be able to go swimming with Amazon pink dolphins. We also could fish for the dreaded piranha. We did both and it turns out that we swam with dolphins in roughly the same area that we fished for piranha. So, yes, in addition to swimming with dolphins (who were actually some distance away, so whether we were swimming “with’ them might be open to debate,) we were also swimming with piranha. And we didn’t get eaten. No one in our group was so much as nibbled on.

We were to learn that of the forty or so species of piranha, around thirty are vegetarians. The remaining eleven meat eaters rely primarily on carrion. They will eat very small fish and turtle hatchlings and even from time to time take a bite of the cartilage on larger fish’s tales, but larger prey, not so much. So yes, piranha will eat a human but they would prefer it to be dead first.  As our naturalist guides pointed out, we had been seeing local children swimming in the Amazon for several days, and they hadn’t been attacked either.

But how did piranha get such a bloody reputation?  Believe it or not, it was probably Teddy Roosevelt’s fault. As explained by the Mental Floss blog:

In 1913, the former president made a much-ballyhooed trip down the Brazilian Amazon. Like anyone hosting a dignitary, the locals wanted to put on a show for Roosevelt. So days before the roughrider arrived, they used nets to block off a section of the Amazon. Then they caught piranhas from other parts of the river and tossed them into their makeshift aquarium, all while keeping the fish unfed. When Roosevelt rolled into town, the locals finally appeased their captives by chucking a live cow into the water. The piranhas wasted no time. As they sank their teeth into the meat, the water foamed up and turned red. In minutes, the cow’s skeleton was all that was left.

To Roosevelt’s eye, the piranha seemed like a perfect killing machine. He wrote at length about the fish’s bloodthirsty disposition and grisly efficiency, saying, “The head with its short muzzle, staring malignant eyes, and gaping, cruelly armed jaws, is the embodiment of evil ferocity; and the actions of the fish exactly match its looks.” Americans, for their part, devoured the beloved president’s travel memoirs, and suddenly every river and lake seemed a bit more ominous.

This not to say that piranha are not dangerous. One of our guides attempted to grab a piranha that had jumped off a hook into the boat and was bitten in the finger for his trouble. Still, the piranha got the worst end of the deal. That evening, the cook aboard the ship prepared the piranha. They were tasty, if slightly on the boney side.