Pygmy Corydoras

The Pygmy Corydoras (Corydoras pygmaeus) is one of the smallest species in the genus Corydoras, a large group of armored catfish in the family Callichthyidae native to South America. It is found in slow-moving tributaries of the Madeira River system within the Amazon basin in Brazil and Bolivia. Unlike many of its larger relatives, which stay near the substrate, Pygmy Corydoras often swim in the mid-water column in tight schools, a behavior more typical of characins than catfish. Its diminutive size and social nature have made it a well-known species among freshwater aquarium keepers, and it remains common and unthreatened throughout its native range.

Pygmy Corydoras are tiny, torpedo-shaped catfish easily distinguished from similar species by their minute size and distinctive stripe pattern.

• Body: short, slender, cylindrical, covered in bony armor plates rather than scales
• Color: pale silvery-tan with a bold dark horizontal stripe running the length of the body from snout to tail base
• Fins: small, translucent, rounded; a small adipose fin present
• Barbels: short whisker-like barbels flank the small downturned mouth
• Size: adults reach only about 2-3 cm, among the smallest of all catfish The continuous dark lateral stripe and mid-water schooling behavior separate it from bottom-hugging Corydoras species of similar size.

Pygmy Corydoras occur in shallow, slow-flowing tributary streams, backwaters, and flooded margins of the Madeira River drainage in the Amazon basin of Brazil and Bolivia. They favor soft, sandy or leaf-litter-covered substrates in warm tropical water, typically shaded by overhanging vegetation. Unlike many bottom-dwelling relatives, they are frequently found suspended in open water among submerged branches and roots rather than resting directly on the substrate. Water in their native habitat tends to be soft and slightly acidic, with dense vegetation and abundant cover from riparian growth along stream margins.

Pygmy Corydoras are highly social, forming tight, coordinated schools that swim in open water rather than staying close to the bottom, an unusual trait among Corydoras species. They feed opportunistically on small invertebrates, algae, and organic detritus, foraging both mid-water and along the substrate. Schooling behavior likely offers protection from predators for such a small species. Like other Corydoras, they can gulp air at the surface and absorb oxygen through the gut in low-oxygen water. Spawning follows a typical Corydoras pattern, with females carrying fertilized eggs between their pelvic fins before depositing them individually on plant leaves or other surfaces.