Midnight Catfish

These catfish reach a length of about 11 cm. Their coloration is grey, adorned with white speckles all over the body. The tall dorsal fin has a first ray resembling a pointed spine, which serves as protection against potential predators. Sexual dimorphism is weakly expressed. Males have a small hook on their anal fin, used during the mating process.

This species is widely distributed throughout South America. It can be found in northeastern Peru, the Brazilian Amazon basin, and also in the Essequibo River and its tributaries. The Midnight Catfish prefers waters with murky conditions and flooded areas of tropical forests, where it finds shelter among tangled underwater roots, in hollow or decaying stumps, and in dense thickets of aquatic vegetation. Fish of this species are nocturnal.

This peaceful and shy species coexists well with calm fish of a similar size. The Midnight Catfish feels comfortable both alone and in a small group. Avoid keeping them with large, overly active, or aggressive fish, as danger threatens not only the catfish but also anyone who tries to attack it: the spine of the dorsal fin can inflict serious injuries.

For keeping a single fish, an aquarium of at least 80 liters is recommended. The aquarium setup should focus on creating many reliable shelters, which can be tangled roots, driftwood, and other elements. The substrate should be soft. Dim lighting is desirable; under such conditions, the Midnight Catfish will appear much more frequently. Under normal lighting, it will primarily hide. Water conditions should be characterized by very weak current or its complete absence, and pH and dGH values should correspond to slightly acidic and soft values at a temperature not exceeding 25°C. Regular aquarium maintenance includes cleaning the substrate of organic waste and weekly water changes of 10–15% of the water volume with fresh water.

In their natural habitat, their diet consists exclusively of insects and their larvae. However, breeders have successfully accustomed these catfish to dry foods, such as sinking tablets, granules, or high-protein flakes. Since they feed during the dark hours, it is optimal to offer food shortly before the lights are turned off. Over time, as they become bolder, the catfish may start feeding during the day along with other aquarium inhabitants.

As of the preparation of this article, reliable information on the successful breeding of the Midnight Catfish in home aquariums is unavailable. Only professional breeders in commercial aquariums in Europe and America have successfully achieved this. The reproduction process resembles livebearing: internal fertilization occurs thanks to the male's modified anal fin (the very hook mentioned earlier). After this, the female lays her eggs directly on the substrate and leaves them. There is no parental care, and the future offspring are left unattended.

The main cause of most diseases in these fish is unsuitable keeping conditions and poor-quality nutrition. If initial symptoms are observed, it is first necessary to check water parameters and the concentration of dangerous substances such as ammonia, nitrites, and nitrates. If the indicators deviate from the norm, they should be brought back into order, and only then should treatment begin.

When choosing a Midnight Catfish, carefully inspect the skin for white spots, injuries, or signs of parasites. A healthy fish should show activity during twilight hours, have clean fins, and clear eyes. Avoid individuals with sunken bellies, which may indicate emaciation or internal diseases. Given the sharp spines on their fins, it is important to use thick bags during transport to prevent punctures. It is recommended to acquire a group of fish, as they feel more confident in the company of their kin.