Corydoras ambiacus

The body pattern of these fish consists of numerous dark speckles on a silvery background, with adults reaching a length of about 6 cm. The base of the dorsal fin is marked with a large black spot, preceded by a golden stripe. Most fins are also adorned with a spotted pattern, with the exception of the ventral and pelvic fins, which are uniformly bluish-white. Interestingly, due to its characteristic spotted pattern, this species is often confused with other similar Corydoras catfish, such as the Black-and-white Corydoras, Agassiz's Corydoras, or the Spotted Corydoras.

The species inhabits the upper Amazon basin, including the tributaries of the Ampiyacu, Yavari, Napo, Nanay rivers, and the lower Ucayali River. It is found in Brazil, Peru, Colombia, and Ecuador. It inhabits freshwater bodies with soft to moderately hard water, preferring areas with slow currents and silty or sandy bottoms.

A peaceful schooling fish, active mainly at dusk and night. In an aquarium, it is recommended to keep a group of 4–6 individuals or more, which helps reduce stress and promotes natural behavior. It is compatible with most non-aggressive fish species, but due to its bottom-dwelling lifestyle, it may compete for space with other bottom dwellers.

The catfish is unpretentious and easily adapts to various conditions, making it an excellent choice for beginner aquarists. Keeping Corydoras ambiacus does not require recreating any specific environment; it can be introduced into almost any freshwater aquarium, the main thing is to ensure proper acclimatization. This species is distinguished by its peaceful nature, so it gets along well with many non-aggressive fish of comparable size. The keeping rules are quite simple and common for most aquarium species. It is important to prevent the accumulation of organic waste, such as food remnants or excrement, as they can disrupt the stability of the nitrogen cycle. It is necessary to maintain the temperature, as well as pH and dGH values, within the permissible range. Regular aquarium maintenance includes equipment prophylaxis, partial water changes with fresh water, and cleaning the substrate and decor elements from plaque and debris. As for feeding, these catfish readily accept almost all commercially available foods. The only condition is that the food must be sinking, as Corydoras ambiacus is a bottom dweller.

An omnivorous species, in nature it feeds on small invertebrates, insect larvae, crustaceans, and organic detritus. In the aquarium, it accepts all types of sinking foods: high-quality dry granules, catfish tablets, as well as frozen or live foods such as bloodworms or brine shrimp. One should not rely solely on leftover food from other fish, as this does not provide a complete diet.

Breeding is typical for representatives of the genus. Spawning is paired or communal, stimulated by water changes with softer and cooler water, which mimics the rainy season. Eggs are laid on the substrate, plant leaves, or aquarium glass. Parents do not show parental care and may eat the eggs, so it is recommended to remove the adults after spawning.

The species is sensitive to water quality and substrate cleanliness. When kept on a coarse or sharp substrate, damage to the delicate barbels is possible, leading to the development of bacterial infections. Like other scaleless fish, it is extremely sensitive to salt content in the water and certain medications containing copper or malachite green in high concentrations.

When purchasing, active fish with clean integuments without visible spots, ulcers, or signs of emaciation should be chosen. It is important to ensure the integrity of the barbels — their absence or damage indicates poor keeping conditions. Healthy individuals should show interest in foraging for food at the bottom and not have sunken bellies.