Adolfo's Twin-stripe Cory

Corydoras duplicareus is frequently confused with the popular C. adolfoi, and the two species are often mixed in shipments. The key distinguishing features are the broader, more intensely orange head stripe in C. duplicareus, a slightly more elongated body, and its origin from the upper Rio Negro drainage rather than the Rio Uaupés system associated with C. adolfoi.

Both species inhabit blackwater, tannin-rich soft and acidic water — typical of the Rio Negro basin, one of the most acidic major rivers in the world. In the aquarium, C. duplicareus therefore performs best in very soft, slightly acidic conditions with tannins from Indian almond leaves or peat. It is less forgiving of hard or alkaline water than many other cories.

This is a specialist's species that rewards careful water management. The vivid orange head stripe contrasting with the bold black body stripe and pale silver body makes it one of the most attractive small cories available. Keep in groups of six or more, maintain blackwater conditions, and feed varied high-quality foods for the best colouration and long-term health.

Water: Very soft and acidic, pH 5.5–7.0, temperature 23–27°C; Rio Negro blackwater conditions strongly recommended. Tank: 80 L with fine sand, leaf litter, driftwood, and subdued lighting; avoid carbonate-buffered substrates. Feeding: High-quality sinking pellets, frozen bloodworm, Daphnia, and Mysis; varied diet maintains vivid colouration. Breeding: Possible in very soft, acidic water; eggs deposited on leaves and glass; small clutches typical. Compatibility: Peaceful; best with other blackwater species from the Rio Negro; avoid hard-water tankmates.