

The black piranha (Serrasalmus rhombeus) is a famed opportunistic carnivore of the Amazon and Orinoco river systems, but they are not aggressive. However, Piranhas are quickly efficient. Feeding cooperatively, they take down weaker and older animals at the water's edge. Photographed in an oxygenated aquarium adjacent to its habitat in Laguna Pañacocha, Amazonian Ecuador. The fish was released to the lagoon after photography.