Blue cory - Corydoras nattereri

Scientific name: Corydoras nattereri

Common name: Blue cory

Family: Callichthyidae

Usual size in fish tanks: 5 - 7 cm (1.97 - 2.76 inch)

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Recommended pH range for the species: 6.5 - 7.8

Recommended water hardness (dGH): 4 - 15°N (71.43 - 267.86ppm)

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Recommended temperature: 20 - 24 °C (68 - 75.2°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Bottom levels

Origin

Corydoras nattereri, commonly known as the Blue Cory, originates from the rivers and freshwater waterways of South America, specifically in Brazil. In their natural habitat, these fish are often found in slow-moving waters with sandy or fine gravel substrates. These environments are typically shaded by dense vegetation, offering plenty of hiding spots and a rich variety of organic matter. Understanding their natural habitat can help aquarists recreate similar conditions in the home aquarium, ensuring the Blue Corys thrive.

Appearance

The Blue Cory has a distinctive metallic blue sheen that covers most of its body, giving it an attractive and vibrant appearance. They have a white underbelly and sport the typical elongated body shape characteristic of Corydoras species. Blue Corys have a pair of barbels around their mouths, which they use to search for food along the substrate. They usually reach an adult size of about 5-6 cm (2-2.4 inches) in length, making them suitable for medium-sized community tanks.

Feeding and Diet

Blue Corys are not picky eaters and will readily accept a variety of foods, making them easy to feed in a community aquarium. For their staple diet, offer high-quality sinking pellets or flakes that are suitable for bottom feeders. These can be supplemented with occasional treats such as bloodworms, brine shrimp, and daphnia, which can be provided either live or frozen. These protein-rich foods not only support their growth but also enhance their vibrant coloration.

Since Blue Corys are bottom dwellers, it's essential to ensure that the food reaches the substrate. You can feed them in the evening or when the aquarium lights are dimmed, as this encourages their natural foraging behavior. Overfeeding should be avoided to prevent water quality issues, so offer small portions and remove any uneaten food after feeding.

Tank Setup and Environment

To create an ideal environment for Blue Corys, set up a well-planted aquarium with plenty of hiding spots. A tank of at least 60 liters (15 gallons) is recommended for a small group. Blue Corys prefer cooler water temperatures, around 22°C (72°F), making them an excellent choice for cooler community tanks. Use a soft substrate like sand or fine gravel to allow them to dig and forage without damaging their delicate barbels. Incorporating driftwood, rocks, and aquatic plants such as Java Fern, Anubias, and Amazon Swords can provide shelter and help maintain water quality.

Blue Corys thrive in well-oxygenated water with a moderate flow, so an efficient filtration system is necessary. They prefer slightly acidic to neutral water, with a pH range of 6.5 to 7. Regular water changes and proper maintenance are crucial for keeping the tank clean and the water parameters stable. Avoid keeping them with aggressive or larger fish that may outcompete them for food or stress them out.

Behavior and Compatibility

Blue Corys are peaceful and social fish that do best in small groups of at least 5-6 individuals. When kept alone, they can become shy and may hide more often. In a group, they exhibit interesting social behaviors, often swimming together and foraging along the substrate as a team. They are ideal for community tanks and can coexist peacefully with other non-aggressive species such as small tetras, rasboras, and dwarf cichlids.

Due to their peaceful nature, it's best to avoid housing them with aggressive or highly territorial species that might bully them or disturb their natural behavior. Tank mates that occupy different levels of the aquarium, like small schooling fish and invertebrates, are perfect companions for Blue Corys.

Sexing

Sexing Blue Corys can be challenging, but there are some subtle differences between males and females. Adult females are generally larger and have a rounder, stockier body shape, especially when viewed from above. Males tend to be slimmer and may have slightly more intense coloration. These differences are more noticeable during the breeding season when females are carrying eggs.

Breeding

Breeding Blue Corys can be a rewarding experience for aquarists. To encourage spawning, condition a group of adults with a varied diet rich in live or frozen foods, such as bloodworms and brine shrimp, for about a week. Performing cooler water changes can help trigger spawning behavior. During breeding, the female will carry the eggs in her pelvic fins to a chosen spawning site, usually on the glass, plants, or other flat surfaces. This process will be repeated until around 100 eggs are deposited.

The eggs typically hatch in 3-4 days, and the fry become free-swimming shortly afterward. At this stage, they can be fed newly hatched brine shrimp or specialized fry foods. Maintain high water quality and gentle water flow in the breeding tank to ensure the fry develop healthily. Providing plenty of hiding spots and using a sponge filter can help protect the delicate fry from being sucked into the filtration system.

Lifespan

The expected lifespan for Corydoras nattereri is 3-5 years, though they can live longer with optimal care. Providing a clean environment, a balanced diet, and stable water conditions are key factors in ensuring they reach their full lifespan. Regular tank maintenance, including water changes and monitoring water parameters, will contribute to their overall health and longevity.

Short Description

The Blue Cory (Corydoras nattereri) is a hardy and adaptable species that adds activity and charm to a community aquarium. Preferring cooler water temperatures, they thrive in well-planted tanks with plenty of hiding spots. As bottom dwellers, they help keep the substrate clean by scavenging for leftover food. Blue Corys are best kept in small groups, where they display their natural social behaviors and enhance the dynamic of a peaceful community tank.