Redtail Barracuda

The body structure of this fish is elongated and slender, outwardly resembling a pike. Its large mouth is equipped with numerous sharp teeth, which are clearly visible when the mouth is open. The coloration is usually silvery or with a golden sheen, with the belly being lighter. The fins are transparent, sometimes with an orange tint, and the bright red tail with a striking black spot at the base makes a particular impression.

The species was described from Marajó Island in the Brazilian state of Pará. Populations from the Paraná and Uruguay basins are now assigned to another species, Acestrorhynchus pantaneiro, so the range of A. altus is probably restricted to the lower Amazon and some of its tributaries. They prefer clear waters with moderate currents, where they can often be found in groups. The barracuda's diet consists exclusively of live fish, and they can hunt prey up to half their own size.

In natural conditions, these fish are often found in small schools, but when kept alone in a home aquarium, they become timid and quickly panic at loud noises. The ideal option is to keep several individuals (3–4) in an aquarium with other fish of comparable or slightly larger size. The Redtail Barracuda does not show aggression and will not attack tankmates unless it perceives them as potential food.

Like any large predator, the Redtail Barracuda produces a significant amount of waste, so it is crucial to provide it with an effective filtration system. It is recommended to use high-performance filters which, in addition to cleaning, will create the necessary water movement in the aquarium. Regular water changes of 30–50% every two weeks are as important as installing quality filtration. Other necessary equipment includes an aerator, heater, and lighting system. For decor, sturdy root plants placed along the aquarium walls are preferred. The central part should remain free to provide the fish with ample swimming space. The substrate can be any type, and the presence of shelters is welcome. Shelters can be natural elements (snags, roots, rock formations) or artificial ones (castles, sunken ships, etc.), with their height not exceeding half the height of the tank.

Being a carnivorous species, this fish feeds exclusively on live fish. Pieces of meat or dead prey will not interest this predator. It is advisable to provide an additional tank for breeding small, prolific fish, such as livebearers. This will ensure a constant supply of food. They must not be fed mammalian or avian meat: the lipids it contains cannot be properly metabolised by the fish and lead to excess fat deposits and even organ degeneration.

Currently, all individuals of this species offered in commercial networks have been caught from the wild, as they do not breed in captivity.

Most often, these fish enter home aquariums from specialized stores rather than directly from the river, which means they are adapted to confined spaces and food unnatural to the wild. As a rule, such fish do not have health problems.

When choosing a Redtail Barracuda, special attention should be paid to the condition of the fins and skin, as this species often suffers from injuries during transportation and keeping in cramped conditions. A healthy fish should show activity and alertness, not apathy. Avoid individuals with visible damage, body film, or signs of emaciation, as restoring the health of wild-caught individuals can be extremely difficult. Keep in mind that this species is a timid predator prone to panic, so in the store, the fish may dart around the aquarium and injure itself against the walls. When purchasing, it is recommended to: — check for absence of jaw and fin damage; — ensure the fish is well-fed, without sunken sides; — clarify whether the fish is accustomed to non-live foods, as transitioning them can take a long time; — choose individuals of comparable size when buying a group to avoid intraspecific aggression.