They're considered one of the most dangerous fish species, but are piranhas really carnivores? Matt Clarke explains.
No. Research on the Red bellied piranha (Pygocentrus nattereri) and its relative Serrasalmus sp. aff. brandtii have shown that they’re actually generalist feeders — and not the pure carnivores they’re made out to be.
Scientists studying these piranha species caught them three times a month and examined the foods that fish of different ages had been eating by dissecting them and looking at their guts to see what foods they were digesting.
Both species are plant eaters, however, the Red-bellied eats much more in the way of vegetation than brandtii.
Of course, there are also other relatives, such as pacus and Metynnis, which are predominantly herbivorous.
Piranhas do not need to be offered live food in the aquarium and do just as well on frozen foods.
This item was first published in the September 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.