Pastaza Cory

Geographic Origin and Biotope: Endemic to the Pastaza River basin in Ecuador (upper Amazon River basin). Populates mountain streams and forest creeks with moderate currents, characterized by mainly clear waters and sandy bottoms riddled with smooth rocks.

Taxonomy and Morphology: Robust member of the long-snouted Corydoras group (Callichthyidae). Significant size (6.5 cm / 2.5 inches). The receding and penetrating cranial profile is a biological adaptation for deep digging in search of annelid worms.

Social Behavior: Quiet giant of the deep. Extremely gregarious, imperatively needs a large school (6-8 specimens) to move safely. Surprisingly peaceful, but often shy in the presence of sudden external movements.

Coloration and Sexual Dimorphism: "Saddle" livery: silvery base coloration minutely spotted with black. Shows a conspicuous black mask over the eye and two or three distinct dark vertical blocks (saddles) along the flank and dorsal. Females significantly more corpulent and taller.

Aquarium Setup: Fine inert sand mandatory. They tolerate smooth and non-sharp rocks. The ideal setup includes massive branched roots (Manila, Red Moor) and low-light areas guaranteed by floating leaves to alleviate shyness.

Diet and Feeding: Large-sized rooting micropredator. Requires substantial feeding: Loricariid tablets alternated bi-weekly with gluttonous rations of chopped earthworms, large bloodworms, and frozen brine shrimp.

Water Quality: Accustomed to cool Andean flows: ideal thermal range 22-26°C (72-79°F). Very low hardness (GH 2-12). pH between 6.0 and 7.2. Dramatically suffers from peaks in nitrogenous compounds, demanding a very clean and oxygenated bottom.

Compatibility and Tankmates: Spectacular for large Amazonian biotopes. Ignores anyone but lets itself die of starvation if dominated on food by large Cichlids (Geophagus) or Loaches. Perfect with schools of Tetras (Neons, Rummy Nose) and rasboras.

Aquarium Reproduction: T-position reproduction very hard to obtain. Lays very few large adhesive eggs. Fundamental to simulate the onset of the cold rainy season with decisive RO water changes. Imperative to remove the brood to evade cannibalism.

Risks and Diseases: In case of rough substrates, the long barbels will atrophy causing death by starvation. Extremely vulnerable to commercial antiparasitic drugs, requires halved dosages if not strictly avoided.