Leporinus arcus

These individuals grow to 25–30 cm in length. Sexual dimorphism is weakly expressed, and males and females are practically indistinguishable externally. The body has a characteristic pattern of two dark stripes that run from head to tail on a light background. The back is dark gray. Red pigmentation is noticeable on the head and around the mouth, which gave the species its name — Red-lipped Leporinus.

Its natural habitat is in South America, where it is found in numerous river systems, including the Orinoco, in the territories of Venezuela, Guyana, Suriname, and French Guiana. These fish inhabit various biotopes: they can be found in rivers with moderate currents, as well as in calm floodplain lakes and swamps.

The behavior of these fish can vary depending on the number of individuals kept together. Solitary Red-lipped Leporinus can sometimes exhibit aggression, chasing smaller tank mates. However, when kept in groups of 3–4 individuals, they become significantly more tolerant of other fish of comparable or slightly smaller size.

For the successful keeping of a group of 3–4 such fish, an aquarium of at least 700 liters will be required. The decor is chosen arbitrarily and usually includes a sandy substrate, large boulders, driftwood, and floating plants. Rooted vegetation may be damaged, which is due to the dietary characteristics of Leporinus arcus. Long-term and successful keeping of the fish is only possible with the maintenance of stable water conditions within acceptable temperature and hydrochemical parameters. For this, the aquarium is equipped with the necessary equipment, primarily filtration systems, and regular maintenance is carried out: weekly partial water changes with fresh water, timely removal of organic waste, and monitoring of nitrogen cycle product concentrations and other parameters. Given the large size of adult individuals, the water should be well saturated with oxygen, so additional aeration will be very useful.

The Red-lipped Leporinus is an omnivorous species; in the wild, its diet consists mainly of algae, invertebrates, and organic detritus, which it collects from the bottom. In a home aquarium, it readily accepts various types of food, including dry flakes, pellets, frozen, and live foods. It is important to ensure a sufficient content of plant components in its diet.

Aquarium breeding is not documented. In this genus spawning in the wild is linked to migration and rising water during the rainy season: the fish release adhesive eggs and do not guard them. In captivity maturation stops at the pre-spawning stage, and in the farming of related Leporinus species fry are obtained through hormonal induction. No external sexual differences have been described.

This hardy and unpretentious species thrives in a suitable environment. However, deteriorating water quality, namely high levels of pollution, inevitably weakens the fish's immune system, making Leporinus arcus vulnerable to various infections. As a rule, moving the fish to optimal aquarium conditions helps the symptoms of the disease disappear. If the symptoms persist, medication may be required.

When purchasing, choose active individuals with clean fins and no visible skin damage. It is important to assess the fish's behavior in the store: a healthy leporinus shows curiosity, does not constantly hide, and does not show signs of exhaustion or apathy. It is recommended to clarify the keeping conditions and diet with the seller, as adaptation to new conditions in the aquarium requires a stable biological environment. Avoid purchasing individuals with signs of body deformation or an unnaturally swollen abdomen.