Corydoras duplicareus, commonly known as the Duplicate Cory, is a charming and relatively rare species within the vast Corydoras genus, celebrated for its peaceful nature and striking appearance. Native to the Rio Negro basin in Brazil, this species thrives in soft, acidic waters, often found in areas with dense vegetation and sandy substrates. The Duplicate Cory is particularly noted for its striking resemblance to Corydoras adolfoi, hence the name "duplicareus," implying a duplication or close similarity in appearance. However, it distinguishes itself with subtle differences in coloration and patterning.

The Duplicate Cory is characterized by its elegant body shape, with a primary coloration of creamy white to light gold. The most distinctive features include a black band running across its eyes and extending back towards the dorsal fin, coupled with another prominent black mark on the dorsal fin itself. The vibrant orange or yellow coloring on the fish's head, just above the eyes and towards the dorsal fin, adds to its visual appeal, making it a sought-after species for freshwater aquarium enthusiasts.

Creating an optimal environment for Corydoras duplicareus involves replicating the conditions of their natural habitat as closely as possible. This includes a well-planted aquarium with plenty of hiding spots and a substrate of fine sand or smooth gravel to protect their delicate barbels used for sensing food. The inclusion of driftwood and leaf litter can enhance the naturalistic setting and mimic the tannin-stained waters of their native environment. Soft, slightly acidic water conditions with stable temperatures within the tropical range promote the health and well-being of the Duplicate Cory.

The diet of Corydoras duplicareus is omnivorous, with a natural inclination towards small invertebrates and organic detritus in the wild. In captivity, they should be provided with a varied diet that includes high-quality sinking pellets or tablets formulated for bottom dwellers, supplemented with live or frozen foods such as daphnia, brine shrimp, and bloodworms. This varied diet helps ensure they receive all the necessary nutrients for optimal health and vitality.

Breeding Corydoras duplicareus can be a rewarding experience, as they are egg layers, with a preference for spawning on flat surfaces or within the cover of dense vegetation. Providing a breeding tank with soft, slightly acidic water and increasing the frequency of feeding high-quality live foods can encourage spawning behavior. The eggs are relatively large and adhesive, allowing them to be easily transferred to a separate rearing tank if desired. The fry are small and should be fed infusoria or commercially available fry foods until they are large enough to accept larger fare.

Caring for Corydoras duplicareus involves regular maintenance routines to ensure the water quality remains high, with frequent water changes and effective filtration. Their peaceful nature and small size make them excellent candidates for community tanks, where they can be kept with other similarly sized and non-aggressive fish species. However, their specific dietary, environmental, and social needs should be carefully considered to ensure a harmonious and healthy aquarium.

In summary, Corydoras duplicareus, or the Duplicate Cory, offers aquarists the chance to keep a small, peaceful, and beautifully patterned species that adds both visual interest and activity to the freshwater aquarium. While their care requires attention to their dietary, environmental, and social needs, the rewards of keeping Duplicate Corys include the enjoyment of their charming appearance and the dynamic presence they bring to the aquatic setting.