Flag-tail Cory

Geographic Origin and Biotope: Jewel of the Rio Negro basin, in Brazil. Inhabits the bottom of rivers with very clear but distinctly black and acidic waters (blackwater) generated by the massive organic decay (leaf tannins) in the jungle, sheltered from weak sunlight.

Taxonomy and Morphology: Belonging to the Callichthyidae family. Tiny Corydoras (maximum 4.5 cm / 1.8 inches) with a moderately round snout. Has a slender and armored chassis, which visually stands out for a markedly flattened profile compared to others.

Social Behavior: Radical gregariousness. Forces the breeder to purchase large swarms (from 8 to 15 members). Very elusive, it takes time to acclimatize and does not accept external disturbances. Indefatigable rooters if united in their thick reassurance group.

Coloration and Sexual Dimorphism: Undoubtedly one of the most unique corys. Whitish tapered body, adorned with 4 or 5 powerful parallel horizontal black bands along all the flanks. Tail entirely furrowed by parallel blackish stripes (banded-tail pattern). Females much taller and more massive than males.

Aquarium Setup: Setups without very fine sand are torture for this species. The ideal layout is blackwater: very intricate woods, alder cones, thick carpets of dead leaves. The presence of a weak current is tolerated and appreciated.

Diet and Feeding: Omnivorous benthic micro-digger. Nocturnal or evening feeding highly recommended to evade bullying fish. Administer rapid sinking crumbled tablets, obligatorily combining brine shrimp nauplii and red bloodworms/tubifex (live or frozen).

Water Quality: The native Amazonian black waters demand acidic/neutral pH (6.0 - 7.2), extremely low GH (2-12) and a constant temperature at 22-26°C (72-79°F). Bacterial and nitrate accumulation will lead to lethargy, infections and early death; careful changes are vital.

Compatibility and Tankmates: Delicious companion, tiny and shy, must be introduced solely with small gentle "dither fish": schools of Paracheirodon innesi/axelrodi, small Nannostomus or Otocinclus. Banned large or moderately aggressive fish.

Aquarium Reproduction: Rare trial and for experts. Necessary substantial monsoon simulations (cool RO water changes and live hyper-protein feeding). Classic T-mating with meager deposition of adhesive eggs; extreme parental propensity to eat their own brood.

Risks and Diseases: Any abrasive substrate fatally wears the barbels leading to silent starvation and fungal infection of the mouth. They tolerate aggressive preparations very badly, especially copper ones, making it necessary to halve the curative dose.