Tambaqui

The tambaqui, also known by various names including black pacu, black-finned pacu, giant pacu, cachama, and gamitana, is a large freshwater fish indigenous to tropical South America. It belongs to the Serrasalmidae family and is the sole species in the genus Colossoma, although it formerly included species now classified under Piaractus.

Tambaqui inhabit the freshwater environments of the Amazon and Orinoco basins and are also popular in aquaculture outside their native range. These fish can grow to substantial sizes, reaching up to 1.1 meters in length and weighing as much as 44 kilograms, although they are typically around 0.7 meters long. Tambaqui possess unique molar-like teeth designed for crushing seeds and nuts, and they primarily consume plant matter.

A remarkable trait of the tambaqui is its ability to obtain oxygen directly from the air when water oxygen levels are low. While they thrive in freshwater, they struggle in saline conditions exceeding 20 g/L. They are also capable of adapting to variations in pH levels thanks to their versatile gut microbes.

Tambaqui play a crucial role in their ecosystem by facilitating seed dispersal. They consume fruits and seeds and subsequently spread them through the water, aiding in plant propagation. Their diet consists of fruits, seeds, zooplankton, and other small organisms.

The tambaqui is a popular food fish in South America, but overfishing has led to a decline in wild populations. To address conservation concerns and satisfy demand, tambaqui is farmed in countries like Brazil and Thailand. Additionally, some introduced populations have flourished in the wild in various regions.