Mini Cory, Light-Spot Catfish (Gastrodermus nanus) — 2,5-3cm

Overview

If you're searching for small corydoras for sale UK, the Gastrodermus nanus—commonly called the Mini Cory or Light-Spot Catfish—is a delightful micro-predator that brings continuous activity to the lower levels of your aquarium. Endemic to the Suriname and Maroni River basins in Suriname and the Iracoubo River basin in French Guiana, this peaceful schooling catfish rarely exceeds 3.5 cm in captivity, making it one of the smallest bottom-dwellers available. Its compact size and gentle temperament have earned it a loyal following among aquarists who appreciate the charm of miniature South American species. At Tropical Fish Co, we supply healthy, well-acclimated juveniles ready to thrive in soft, clean water.

Appearance and Coloration

Gastrodermus nanus displays a subtle, sand-and-cream base color adorned with fine spotting and faint banding along the flanks. The dorsal and pectoral fins are slightly elongated compared to other dwarf Corydoras, and the barbels remain delicate and sensitive. Under subdued lighting, the fish exhibits a gentle iridescence that shifts from pale bronze to soft gold. Juveniles start at 2.5 cm and reach full size within six months, maintaining their petite proportions throughout adulthood. The armored plates are clearly visible along the body, a hallmark of the Callichthyidae family.

Natural Habitat and Distribution

This species inhabits slow-flowing tributaries and shallow forest streams where leaf litter and fine sediment cover the substrate. Water conditions are typically soft, slightly acidic, and heavily tannin-stained. During the wet season, these catfish move into flooded forest areas where they forage among submerged roots and decaying vegetation. The natural environment is warm (22–26 °C), dimly lit, and rich in small invertebrates. Replicating these blackwater conditions at home will encourage natural foraging behavior and vibrant health.

Aquarium Setup and Décor

A 40-litre aquarium is the absolute minimum for a small group of five or six. Use soft sand or ultra-fine rounded gravel as the substrate to protect the delicate barbels. Décor should include driftwood, rounded pebbles, and live plants such as Anubias, Java fern, or Amazon swords to provide shade and cover. Floating plants help diffuse overhead lighting and create the dappled conditions these fish prefer. Avoid sharp-edged rocks or coarse substrates, which can damage the sensitive barbels and lead to infection. A tight-fitting lid is essential, as even small catfish may explore surface areas at night.

Feeding and Nutrition

Gastrodermus nanus is an omnivore with a preference for small live and frozen foods. Offer quality micro-pellets or wafers designed for bottom-feeders, supplemented with frozen or live bloodworms, daphnia, brine shrimp, and cyclops. Occasional blanched vegetables such as courgette or spinach can be offered, though meaty foods form the bulk of the diet. Feed once or twice daily in small portions, ensuring food reaches the substrate before mid-water species consume it. Sinking foods prevent competition and allow the catfish to forage naturally along the bottom.

Behaviour and Social Structure

These catfish are highly social and must be kept in groups of at least five individuals to display confident, natural behavior. In smaller numbers they become shy and stressed, spending most of their time hidden. A well-adjusted shoal will constantly forage across the substrate, sifting sand through their gills and occasionally resting on broad-leaved plants. They are active during the day, unlike many nocturnal catfish, and their busy behavior adds a dynamic element to the lower tank zones. Males may display mild territorial posturing during feeding but do not cause harm.

Compatible Tank Mates

Ideal companions include small peaceful tetras (ember, neon, cardinal), rasboras (harlequin, chili), and small livebearers such as Endler's guppies. Other peaceful Corydoras or Gastrodermus species make excellent co-habitants, as they occupy similar niches without competition. Cherry shrimp and Amano shrimp can coexist with caution, provided the tank is well planted and the shrimp are not breeding size. Avoid housing with large aggressive cichlids, boisterous barbs, fin-nipping species, or very active bottom-dwellers that outcompete them for food.

Breeding in the Aquarium

Like other Corydoras-type catfish, breeding is usually triggered by excellent water quality, a varied live or frozen diet, and a slight temperature drop or water-change cue. Males are slightly smaller and more streamlined than the plumper females. Eggs are typically laid on glass, plant leaves, or smooth surfaces, and the adults may consume them if not removed promptly. Spawning often occurs after a series of partial water changes with cooler water. Fry require infusoria or liquid fry food initially, graduating to micro-worms and finely crushed flake within a week. Breeding success is modest but achievable with patience and attention to water conditions.

Why Buy from Tropical Fish Co

At Tropical Fish Co, every Mini Cory is quarantined, health-checked, and acclimated to UK water conditions before dispatch. We source our fish from reputable suppliers who prioritize ethical collection and sustainable practices. Our livestock arrives in insulated packaging with heat packs during colder months, ensuring safe transit. With decades of combined fishkeeping experience, our team is available to answer questions about care, compatibility, and tank setup. Whether you're building your first nano community or expanding an established aquarium, we're here to support your success. Order with confidence and enjoy premium freshwater fish delivered to your door.