Pacu, Giant

Colossoma macropomum

Giant Pacu are large freshwater fish, growing up to 3.2 feet and weighing up to 66 pounds. They are similar in body shape to piranhas. The body is tall and laterally compressed with large eyes and a slightly arched back. The pectoral fins are relatively small. The body is black to gray in color, with blemishes mid-body. The fins are all black.








South America: the Amazon and Orinoco River basins


Tropical freshwater river systems

Life Expectancy

15 years

Sexual Maturity


In the wild, they eat fruits and nuts that drop into the water.


IUCN - Not Listed


Giant pacus are usually solitary, generally peaceful but skittish fish. Adults stay in flooded forests during the first 5 months of flooding and consume fruits and grains. Young and juveniles live in black waters of flood plains until sexual maturity.


Pacu and piranha have similar teeth, although the difference is jaw alignments; piranha have pointed, razor-sharp teeth in a pronounced underbite, whereas pacu have squarer, straighter teeth in a less severe underbite, or a slight overbite.

Special Interests

Around 10% of a giant pacu’s weight is fat. The world record recognized by the International Game Fish Association (IGFA) belongs to the Brazilian Jorge Masullo de Aguiar with 70.5 lbs (32.4 kg). The giant pacu is the second largest scaled fish in the Amazon Basin. Giant pacu are in the subfamily Serrasalminae, which means "serrated salmon family" and refers to the serrated keel running along the belly of these fish. Pacu is a term of Brazilian Indian origin. When the large fishes of the Colossoma genus entered the aquarium trade in the US and other countries, they were erroneously labeled pacu. In the Amazon, the term pacu is reserved to smaller and medium sized fishes in the Metynnis, Mylossoma and Myleus genera. The Colossoma macropomum fish are known as tambaqui, whereas Piaractus brachypomus is known as pirapitinga.Theodore Roosevelt wrote of catching and eating pacu in his book Through the Brazilian Wilderness. He described them as "good-sized, deep-bodied fish," and noted, "They were delicious eating."



Today, the Amazon River is experiencing a crisis of overfishing. Both subsistence fishers and their commercial rivals compete in netting large quantities of pacu, which bring good prices at markets in Brazil and abroad. Pacu have been discovered in Alabama, Arizona, Arkansas, Colorado, Georgia, Idaho, Indiana, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Missouri, Nebraska, New Hampshire, New York, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, South Carolina, Texas, Utah, Wisconsin, and Wyoming.

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