Schwartz's Corydoras

Geographic Origin and Biotope: Purus River basin (Brazil). This large tributary of the Amazon offers clear but sediment-laden waters and large areas of flooded forest with soft bottoms.

Taxonomy and Morphology: Schwartz's Corydoras (Corydoras schwartzi). Robust species, often mistaken for C. trilineatus, but schwartzi has a white dorsal spine and a very distinct broken horizontal line pattern.

Social Behavior: Very gregarious, active and exploratory. Must live in schools of at least 6-8 individuals. If isolated or kept in too low a number, it will spend its entire life hiding, fearing predators.

Coloration and Sexual Dimorphism: Bright silvery body. In addition to the classic black mask passing through the eye, the flanks are marked by parallel horizontal lines composed of black dots. The white, pointed dorsal spine is a trademark. Males much more tapered.

Aquarium Setup: Minimum 80 cm (32 inches) aquarium. Fine sand mandatory, as for all congeners. To alleviate its natural initial shyness, place almond leaves, Mangrove wood and densely planted areas (Echinodorus).

Diet and Feeding: Bottom micro-predator. Administer specific tablet food (e.g. with spirulina or fishmeal), but never lack live or frozen food (tubifex and brine shrimp).

Water Quality: Not particularly demanding regarding water chemistry, but absolutely does not tolerate negligence in cleaning. Nitrates and organic pollutants on the bottom cause irreversible necrosis.

Compatibility and Tankmates: Calm and harmless. Perfect with Tetras (Neons, Cardinals, Hemigrammus), Rasboras, Loricariids, Guppies and small Cichlids. Not to be associated with aggressive Botias or large predators.

Aquarium Reproduction: Swollen females release huge quantities of sticky eggs. The reproductive "trigger" is a 30-50% cold water change, simulating the Amazonian rains.

Risks and Diseases: The greatest threat to C. schwartzi (and to the aquarist) is the transport bag: this species, if panicked, secretes toxins from the axillary mucus which are lethal in unfiltered water.