Tambaqui (Black Pacu)
Colossoma macropomum
The True Titan of the Characins (90-110 cm / 3-4 feet, up to 90 lbs). Often misidentified and sold as the Red-Bellied Pacu, the Tambaqui is actually a significantly larger, more massive, and darker solitary monster. It is the single largest scaled characin in South America, growing into an incomprehensibly thick, heavy, solid black or charcoal-grey disc of muscle. It possesses horrifyingly strong jaws equipped with flat, human-like molars capable of crushing rock-hard walnuts. It is absolutely impossible to keep humanely in standard home aquaria and is strictly reserved for massive 2,000+ gallon indoor tropical ponds or public aquariums.
Temperatura da água
22 - 28 °C
Valor de pH
5.5 - 7.5
Tipo de água
Água doce
Nível do tanque
Meio
Tamanho adulto
90 cm
Volume mínimo do tanque
>= 500 L
Grupo mínimo
>= 1
GH
1 - 15 dGH
KH
1 - 7 dKH
TDS
25 - 295 ppm
Condutividade
39 - 461 uS/cm
Descrição da espécie
Geographical Origin and Habitat: Native to the Amazon and Orinoco basins. This colossus inhabits main rivers, floodplains and flooded forests, where it feeds on the fruits and seeds that fall from the trees above during the rainy season.
Taxonomy and Morphology: Tambaqui / Black Pacu (Colossoma macropomum). Often confused with the Piranha due to the discoid shape of the body. However, unlike the Piranha, the Tambaqui has flat human-like teeth (molars) used to crush very hard nuts and seeds.
Social Behavior: It is an extremely peaceful and tolerant fish, although it is very shy and easily frightened (a frightened 20 kg specimen can literally smash the aquarium glass by headbutting it). As a juvenile it lives in schools, as an adult it is more solitary.
Coloration and Sexual Dimorphism: Lead gray to uniform charcoal black coloration, sometimes with olive hues. Juveniles have a reddish abdomen and dark spots, which is why they are sold as "vegetarian piranhas". No obvious sexual dimorphism.
Cuidado, criação e companheiros de tanque
Aquarium Setup: NOT A HOME AQUARIUM FISH. Grows up to 1 meter (39 inches) and can weigh 30 kg (66 lbs). Requires mammoth tanks (minimum 3,000 liters / 800 gallons). No plants (it would eat them all), only huge roots anchored to the ground and industrial filtration.
Diet and Feeding: Omnivore (mainly frugivore). Literally devours buckets of food: whole apples, grapes, zucchini, nuts, giant koi pellets and crustaceans. It has an insatiable appetite and produces an impressive organic load.
Water Quality: Very resistant to chemical variations, but its size produces so much ammonia that the water quality collapses without huge pond filters and immense weekly water changes.
Compatibility and Cohabitation: Peaceful with fish too large to be swallowed (e.g. giant Arowanas, huge Plecostomus or Redtail Catfish). It will inevitably swallow small and medium-sized fish that it mistakes for fruits.
Aquarium Breeding: Impossible to breed in private aquariums due to size and migratory needs. It is artificially reproduced (with hormone injections) in aquaculture in South America for food purposes.
Risks and Diseases: The main risk is not for the fish (very hardy), but for the aquarist: buying cute 5 cm babies inevitably leads to having to get rid of them when they reach 40 cm in a few months. Risk of lethal head trauma if it gets scared and hits the glass.
Origem e distribuição geográfica
Native to the Amazon and Orinoco basins. This colossus inhabits main rivers, floodplains and flooded forests, where it feeds on the fruits and seeds that fall from the trees above during the rainy season.
Origem
Oceanos tropicais e recifesAmazônia, Orinoco e GuianasAmérica do NorteEuropa, Mediterrâneo e Ásia Ocidental
Perfil de peixe
- Temperamento
- Semi-aggressive
- Despite its fearsome jaws and giant size, this is a surprisingly shy and peaceful fish that does not show unprovoked aggression. However, its tendency to startle easily makes it potentially dangerous, as a panicked specimen can injure itself by violently hitting aquarium decor or glass. It is a gentle giant that requires a quiet environment free from sudden stressful stimuli.
- Dieta
- Omnivore
- In the wild, this giant is primarily frugivorous and is considered an important seed dispenser in flooded forests. In the aquarium, it requires a highly varied omnivorous diet that includes abundant plant matter such as zucchini, apples, grapes, and peas, alongside high-quality pellet foods designed for large fish. Crustaceans and insects can also be offered, but the vegetable component must remain predominant to prevent digestive issues.
- Expectativa de vida
- 15-25 years
- Tamanho adulto
- 90 cm
- Proporção sexual
- Solitary
- The concept of a specific sex ratio is generally not applicable to the black pacu in home aquariums due to the extreme impracticality of housing multiple adults. Because they rapidly grow to over 3 feet in length, even a single specimen requires an enclosure of several thousand gallons. Breeding them in captivity requires massive aquaculture ponds and is not feasible for the standard hobbyist. Therefore, they are almost exclusively kept as solitary individuals in private collections.
- Frequência de alimentação
- Twice daily
- Due to their colossal size and active metabolism, juveniles should be fed twice daily. For mature adults, a single substantial daily feeding or even feeding every other day is sufficient to prevent excessive fat accumulation. It is essential to carefully dose the food quantity to avoid overloading the aquarium's filtration system.
- Carga biológica
- Extreme
- The black pacu produces an exceptionally massive bioload due to its enormous adult size and voracious appetite. They are incredibly messy eaters that require vast amounts of food, resulting in significant solid and dissolved waste production. To maintain adequate water quality, an extremely powerful, oversized filtration system and frequent, large-scale water changes are mandatory. The biological filtration capacity must be heavily reinforced to process the high levels of ammonia they generate on a daily basis.
- Fluxo
- Stagnant
- This fish prefers moderate to weak water flows, reminiscent of the floodplains and slow river channels of the Amazon. Powerful filtration is absolutely necessary due to the high bioload, but the filter outputs should be positioned to avoid creating excessive currents. Calm water zones allow this large fish to rest without expending too much energy.
- Risco de salto
- Yes
- Due to their massive size and powerful musculature, black pacus pose a severe jump risk, particularly when startled or during feeding frenzies. A panicked pacu can easily smash through glass lids or push off light plastic covers. Heavy, securely fastened tank lids made of thick acrylic, polycarbonate, or reinforced mesh are required to contain them safely. Preventing sudden disturbances and maintaining low stress levels is crucial to minimizing their explosive darting behaviors.
- Reprodução
- Oviparous
- Reproduction of the Tambaqui is impossible to achieve within standard home aquariums due to the titanic size of the breeders and their need for migratory spawning. In South America, this species is successfully bred on a large scale in commercial aquaculture using hormonal stimulation in massive earthen ponds. In the wild, eggs are released in open waters, and there is no form of parental care.
- Compatibilidade e companheiros de tanque
- With caution
- Due to their massive size, Tambaqui can only be kept with similarly large and robust fish that cannot be mistaken for food. Good tankmates include large Arowanas, large catfish (such as giant Plecostomus), or other fish from the Serrasalmidae family. Any small or medium-sized fish will inevitably be swallowed or accidentally injured.
- Nível do tanque
- Middle
- The black pacu is a widely roaming fish that aggressively utilizes the mid-to-upper levels of the water column. In their natural habitat, they are known to swim near the surface to consume fruits and nuts that fall from overhanging trees. In the aquarium, they are highly active, open-water swimmers that require massive amounts of unobstructed swimming space. They will traverse all levels but predominantly patrol the middle and upper zones looking for food.
Modelos e parâmetros científicos
FishBase
Acesso aos dados científicos oficiais da espécie
FishBase v25.04Dados sincronizados em: 15/06/2026
- Nível trófico
- 2 ± 0 se
- Resiliência
- Média (1,4 - 4,4 anos)
- Unicidade filogenética (PD50)
- 1
- Relação bayesiana comprimento-peso
- a = 0.02239, b = 2.99
- VulnerabilidadeVulnerabilidade de moderada a alta (47 / 100)
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