Corydoras semiaquilus

Adults of this fish reach an average length of 6 cm. They have the characteristic body shape of Corydoras, but their snout stands out for its elongated form, distinguishing them from most members of the genus. As the name suggests, the coloration of the Black Peruvian Cory is dominated by dark tones in the dorsal region, while the belly has a contrasting light shade.

The species inhabits the Amazon River basin in Brazil, Colombia, and Peru. It prefers the bottom layers of water bodies with sandy substrate. In nature, it is found in tropical conditions with water temperatures of 22–26°C, pH 6.0–8.0, and general hardness of 2–25 dGH.

This fish is distinguished by its calm and peaceful disposition, coexisting perfectly with other unobtrusive species of similar size and temperament. They prefer to be in a group of their own kind. It is worth noting that males of some long-snouted Corydoras species can sometimes show unfriendliness towards each other. This is especially noticeable in small groups, so it is recommended to acquire them in schools of 5–6 individuals. Such behavior, in addition to Corydoras semiaquilus, may be characteristic of closely related species such as Corydoras acutus, Corydoras blochi, and Corydoras treitlii.

For a group of 5–6 individuals, an aquarium of at least 70 liters is optimal. Although the Black Peruvian Cory is not demanding in terms of decor, it is desirable to recreate elements of their natural environment when decorating. An excellent solution would be to use a sandy substrate, which will allow the catfish to dig, as well as placing natural snags and leaves of some trees on the bottom. Creating areas with dense vegetation will also be beneficial. Lighting should be subdued, or, alternatively, floating plants can be used to create shade.

In nature, it is omnivorous, feeding on small invertebrates such as worms, crustaceans, insect larvae, as well as plant detritus. In the aquarium, it is recommended to use specialized sinking foods for bottom-dwelling fish, supplementing the diet with frozen foods. It is important to ensure that portions are eaten within a few minutes, as leftover food quickly pollutes the water.

Spawning is paired or in groups, with eggs laid on a substrate, such as broad plant leaves or flat stones. Parents do not care for their offspring and may eat the eggs. Stimulation is provided by imitating the rainy season: frequent water changes with cooler water and increased feeding. After spawning, the parents should be removed.

The species has a strong immune system when kept under proper conditions. The main risks are associated with poor water quality, the accumulation of ammonia and nitrites, and injuries to sensitive barbels from rough or sharp substrate. It is recommended to use soft sand and perform regular water changes.

When purchasing, choose active fish without visible damage to fins or skin. It is important to pay attention to the integrity of the barbels, as their absence is a sign of improper keeping. Healthy individuals should show interest in searching for food on the bottom and stay in a school.