The tambaqui (Colossoma macropomum) is a freshwater species of serrasalmid. It is also known by the names black pacu, black-finned pacu, giant pacu, cachama, gamitana, and sometimes as pacu (a name used for several other related species).
It may reach more than 1 m (3 ft 3 in) in total length and 30 kg (66 lb) in total weight.
It is similar in shape to the piranha and is sometimes confused with the carnivorous fish; the tambaqui is tall and laterally compressed with large eyes and a slightly arched back. Body color is basic black to gray with spots and blemishes in its midbody. All the fins are black and the pectoral fins are small. Around 10% of a tambaqui's weight is fat. The world record recognized by IGFA belongs to the Brazilian Jorge Masullo de Aguiar with 32.4 kg (71 lb).
This species is usually solitary. Adults stay in flooded forests during the first five months of flooding, and consume fruits and grains. Young and juveniles live in black waters of flood plains until sexual maturity. The tambaqui feeds on zooplankton, insects, snails, and decaying plants. The species plays an important role in dispersing seeds from fruits.
Relationship to humans
In Thailand, this fish, known locally as pla khu dam (ปลาคู้ดำ), was introduced from Hong Kong and Singapore as part of fish-farming projects, but has adapted to local conditions and thrives in the wild in some areas.
- Froese, Rainer and Pauly, Daniel, eds. (2007). "Colossoma macropomum" in FishBase. July 2007 version.
- Cressey, Daniel (2011-03-23). "Fruit-feasting fish fertilize faraway forests". Nature News. Nature Publishing Group. doi:10.1038/news.2011.177. Retrieved 2011-03-23.
- Yong, Ed (2011-03-22). "Vegetarian piranhas are the Amazon’s champion gardeners". Discover Magazine blogs. Kalmbach Publishing. Retrieved 2011-03-23.
- Anderson, J. T.; Nuttle, T.; Saldaña Rojas, J. S.; Pendergast, T. H.; Flecker, A. S. (2011-03-23). "Extremely long-distance seed dispersal by an overfished Amazonian frugivore". Proc. R. Soc. B (The Royal Society) 278 (1710). doi:10.1098/rspb.2011.0155.
- Colossoma macropomum introduced to Thailand