Pygmy Corydoras – Corydoras Pygmaeus

The Pygmy Corydoras is a small and peaceful freshwater fish that is a favourite among aquarists for its playful nature and ability to thrive in community tanks. Unlike other corydoras species, which spend most of their time at the bottom, these tiny fish are more mid-dwellers, often darting around the tank in small shoals. Their diminutive size and social nature make them an excellent choice for nano and planted aquariums.

Quick Overview

Common Names: Pygmy Cory, Dwarf Cory, Dwarf Catfish
Scientific Name: Corydoras pygmaeus
Popularity: Popular among nano tank enthusiasts and community tank keepers
Adult Size: 1–1.2 inches (2.5–3 cm)
Lifespan: 3–4 years
Sexing: Females are slightly larger and rounder when viewed from above, especially when carrying eggs
Temperature: 72–79°F (22–26°C)
pH Range: 6.5–7.5
Water Hardness: 2–12 dGH
Nature: Peaceful and social

Natural Habitat & Origin

The Pygmy Corydoras is native to South America, and primarily found in slow-moving tributaries and floodplains of the Madeira River in Brazil. These waters are typically soft and slightly acidic, with dense vegetation and a sandy or fine-gravel substrate. Their natural habitat provides plenty of shelter, allowing them to hide from predators while foraging for food.

Appearance & Size

Pygmy Corydoras have a streamlined, torpedo-like body with a silver base colour and a distinctive black horizontal stripe running from their snout to their caudal fin. This pattern provides natural camouflage in their environment. Juveniles start even smaller, around 0.3 inches, and gradually grow to their full adult size of about 1–1.2 inches. Their small size makes them an excellent fit for nano aquariums.

Tank Requirements

Minimum Tank Size: 10 gallons (larger is preferred for groups)
Preferred Tank Setup: Well-planted with open swimming spaces
Substrate and Decorations: Fine sane, driftwood and leaf litter
Tank Mate Options: Small, peaceful fish such as chilli rasboras, ember tetras, and otocinclus
Avoid: Large or aggressive fish like cichlids and bettas

Water Parameters & Conditions

Temperature:  72–79°F (22–26°C)
pH Range: 6.5–7.5
Water Hardness: 2–12 dGH
Filtration & Oxygenation: A gentle filter (such as a sponge filter) is best, as pygmy corydoras prefer slow-moving water
Lighting: Moderate lighting to support plant growth but not too harsh

Diet & Feeding

Pygmy Corydoras are omnivorous and enjoy a varied diet that includes both plant matter and protein-based foods.

Recommended Foods:  High-quality micro pellets, crushed flakes, frozen daphnia, baby brine shrimp, and sinking wafers
Feeding Frequency: 2–3 times per day in small amounts

Behaviour & Compatibility

Pygmy Corydoras are highly social and active fish that prefer to live in groups of at least 6 or more. They are peaceful and thrive in well-maintained community tanks.

Good Tank Mates:  Small tetras, guppies, celestial pearl danios
Avoid: Large or aggressive fish such as angelfish or barbs

Breeding

Breeding Pygmy Corydoras in a home aquarium is possible with the right conditions. To encourage spawning, gradually lower the temperature by a few degrees and perform frequent water changes.

Females will lay eggs on plant leaves, glass, or decorations. Males then fertilize them. Once the eggs are laid, removing the adults is recommended to prevent them from eating the eggs. After about 3–5 days, the eggs hatch into tiny fry, which can be fed with infusoria or crushed high-quality fish food. As they grow, they can transition to baby brine shrimp.

Common Health Issues & Prevention

Like all aquarium fish, Pygmy Corydoras can be susceptible to diseases if water conditions are poor. Some common health concerns include:

• Ich (White Spot Disease): Appears as small white dots on the body and fins; prevented with stable water parameters
• Fin Rot: Often caused by poor water quality; maintain clean water and avoid aggressive tank mates
• Barbel Erosion: Can result from sharp substrate; using fine sand prevents injury

To prevent health problems, regular water changes, a well-balanced diet, and proper tank maintenance are essential.

Pygmy Cory Fun Facts

– Pygmy Corydoras do not just stay at the bottom like other corydoras species—they actively swim in the middle of the tank!

– They have a specialized breathing adaptation, allowing them to gulp air from the surface in low-oxygen environments.

– Unlike many bottom-dwellers, they are shoaling fish and need to be kept in groups.

– Their peaceful nature makes them ideal for planted tanks.

Pygmy Corydoras are an excellent choice for beginner and experienced aquarists alike. Their social nature, ease of care, and small size make them a delightful addition to any well-maintained community tank!