Nanus Cory

Corydoras nanus is a dwarf-sized cory from Suriname rivers, with adults typically reaching only 3–3.5 cm. Its small, compact body is pale cream to tan with fine dark freckles distributed evenly across the flanks, reminiscent of a miniature version of C. ambiacus or C. trilineatus. Despite its small size it is a bold and inquisitive fish that actively explores its environment.

Because of its Suriname origin, C. nanus prefers soft, slightly acidic water with tannins from leaf litter or driftwood. It is a resilient species once established but does not tolerate ammonia or nitrite spikes well, as its small body mass leaves it with less physiological buffer. A mature, stable aquarium with regular water changes is important for long-term health.

This species is rarely traded outside specialist circles but is an excellent choice for nano or species tanks. Keep in groups of eight or more — larger groups produce more confident, active fish. Feed appropriately sized micro-foods and supplement with baby brine shrimp or micro-worm for additional protein.

Water: Soft and slightly acidic, pH 5.8–7.2, temperature 22–26°C; stable, clean water essential for small body mass. Tank: 40 L nano or larger; fine sand, leaf litter, and gentle filtration to avoid strong currents. Feeding: Micro-granules, finely crushed sinking pellets, baby brine shrimp, and micro-worm. Breeding: Possible in soft water; cool water change trigger; small clutches; similar to C. pygmaeus protocol. Compatibility: Ideal with microrasboras, small tetras, and other nano species; avoid large or boisterous tankmates.