Pacu, a fish that is closely related to the Piranha.

Scientific Name: Piaractus mesopotamicus
Family: Characidae

We can find it at the La Plata and Araguaia-Tocantins basins.

It can be up to 31in long and weigh more than 40 lb. Theodore Roosevelt, in his book (Through the Brazilian Wilderness), described them as good-sized, deep-bodied fish, and he said: that they were delicious eating.

This fish feeds on fruits and seeds mainly, but it can also eat leaves, algae, small fish, crustaceans and mollusks, that’s why it’s considered omnivorous.

Their teeth, which may resemble human teeth, are used to cut through vegetation and crush seeds that fall into the water.

Black pacu are commonly sold as 'Vegetarian Piranhas' to home aquarium owners in the USA. But they could be very dangerous to aquariums owners because its powerful bite.

Deep Sea World zoological manager Matthew Kane warned, after an incident with toddler: "Pacus will eat anything, even children’s wiggling fingers."

Photos:Junglephotos

Pirarucu, the biggest freshwater fish of the world.

Scientific name: Arapaima gigas
Family: Arapaimidae

The pirarucu is found only in the Amazon Basin. It appears from the Orinoco, in Guiana to the Ucayali and the lower part of the Amazon River and its tributaries, living in the calm waters of the river bank pools.

It is one of the biggest scaly freshwater fish of the world, reaching up to 3 meter long (118.11 inches) and 250 kilograms (113.5 pounds).

This fish has aquatic respiration, through its gills, and mandatory aerial respiration, through its modified swim-bladder, specially prepared to work as a lung.

The pirarucu eats certain species of catfish and insects. It is known to leap out of the water and grab small birds from the overhanging trees.

They are living fossils belonging to the Osteoglossidae (bony tongue) family of fishes. The "tongue" is about five inches long and bony. Its rough surface is used by natives as a rasp to smooth wood. Its scales are used as nail files and in the making of typical ornaments.

Onça-Negra or Jaguar Hunting a Pirarucu:


Photos:Stingrayaquarium