Raising and Breeding Corydoras Gossei

Origin

The Corydoras Gossei is a relatively newly classified species, discovered in the early 1970s. They are endemic to the tributaries of the Rio Mamore in Brazil, which may explain their late discovery. These peaceful fish have become a favorite in the aquarium hobby, particularly for those interested in breeding Corydoras species.

The tributaries of the Rio Mamore provide slow-moving, well-oxygenated water with sandy or muddy substrates, which mimic the natural environment that these fish are accustomed to. Aquarists looking to replicate this in the home aquarium should aim to provide gentle water movement, plenty of swimming room, and soft, fine substrate to ensure comfort and mimic their natural habitat.

Size of Adult Fish

Adult Corydoras Gossei can reach a length of up to 2 inches (5 cm), making them slightly larger than many other Corydoras species. Their manageable size means they are suitable for mid-sized aquariums.

Growth rate depends on water quality, diet, and general tank conditions. For healthy growth, ensure that juvenile Corydoras Gossei have access to protein-rich foods and pristine water. Though they grow slowly, giving them enough space in the tank will allow them to reach their full size more comfortably.

Tank Size

For keeping a small group of Corydoras Gossei, a tank of at least 20 gallons (75 liters, 16.6 Imperial gallons) is recommended. If breeding, consider a larger aquarium with a bigger footprint for more room during the breeding process. Depth is less important for breeding Corydoras than the horizontal space they require for their bottom-dwelling behavior.

When planning the tank size, consider the number of Corydoras and potential tank mates. A tank with more floor space allows Corydoras to forage comfortably. Additionally, aquarists should avoid overcrowding, which may lead to stress and reduce breeding chances.

Recommended pH

The Corydoras Gossei can tolerate a range of water parameters. The ideal pH is between 6.0 and 7.0. They adapt well to both soft and slightly hard water, making them relatively flexible regarding water chemistry.

Keep in mind that maintaining stable water parameters is more important than aiming for perfection. Frequent fluctuations in pH or water hardness can stress the fish and affect their immune system.

Ideal Temperature

Corydoras Gossei prefer cooler water temperatures, ranging from 22°C to 26°C (72°F - 79°F). Keep them with tank mates that also thrive in cooler waters, ensuring harmony within the tank.

Monitor the temperature consistently to ensure it stays within the ideal range. Sudden temperature drops or increases can cause stress and even shock the fish, which may lead to health complications.

Tank Setup and Maintenance

Maintaining high water quality is essential for keeping Corydoras Gossei healthy. Regular water changes, thorough substrate cleaning, and using a gravel vacuum are necessary to prevent diseases that could affect their delicate barbels. A soft substrate like sand or smooth gravel is ideal. Avoid sharp decorations that might injure the fish, and consider using a heater guard to prevent burns.

Lighting

Subdued lighting is preferable, as bright lights can make these fish feel sluggish during the day. Providing low to medium lighting will keep them more comfortable, and they tend to become more active in the evening. Feeding them during the late hours when they are most active ensures they get their share of food.

Tank Mates

Suitable tank mates include peaceful species like tetras or rasboras. Avoid territorial bottom-dwellers like rainbow sharks, as they could intimidate the Corydoras.

Feeding the Corydoras Gossei

Corydoras Gossei are omnivores and prefer feeding during the evening hours. Offering sinking pellets ensures the food reaches the substrate, allowing them to feed without competing with upper-water fish. Live or frozen foods like daphnia, brine shrimp, and bloodworms are perfect for keeping them healthy and active.

Vegetable Matter

Supplement their diet with algae wafers. Break them into small pieces and distribute them around the bottom of the tank to ensure all fish get their share. These fish were once mistakenly considered scavengers, but they require a balanced diet of both protein and vegetable matter to thrive.

Breeding the Corydoras Gossei

Sexing and Maturity

To distinguish males from females, observe the fish from above. Females will have rounder bodies, especially around the belly area. Acquiring a group of 6 Corydoras is recommended for breeding, as this ensures a mixture of sexes. Note that males take longer to reach sexual maturity compared to other species, often up to 3-4 years.

Breeding Tank Setup

Set up a small tank with a large footprint for breeding, as depth is less important. A shallow tank around 12 inches (30 cm) deep will suffice. Use an air-driven sponge filter to prevent fry from being sucked into filter inlets, and maintain a water flow that is low to medium. You may opt for a bare-bottom tank for easier cleaning, or use pebbles to protect eggs from being eaten.

Water Parameters for Breeding

Keep the pH below 7.0 and the temperature around 26°C (79°F). Adding cooler water during water changes simulates the rainy season, encouraging spawning. Patience is key, as males can take years to mature and fertilize eggs.

Spawning Behavior

When the pair is ready to spawn, they assume the "T-position," where the male positions himself in front of the female’s mouth and releases sperm to fertilize the eggs. The female will carry the fertilized eggs in her pelvic fins and carefully place them on a smooth surface, such as plants or the tank walls.

Protecting Eggs and Fry

After spawning, separate the parent fish from the eggs, as they may attempt to eat them. Fertilized eggs turn an orange-brown color, while unfertilized ones remain white. The fertilized eggs hatch in 2-3 days. Fry feed on their yolk sacs before they are ready for external food like newly hatched brine shrimp or finely crushed flakes.

Words of Warning

Corydoras species have delicate barbels that can become damaged if the substrate is dirty. Ensure regular cleaning of the tank. They also possess a sharp barb near their eye sockets, which can inflict stings on other fish or humans if provoked. Avoid using nets that may entangle the fish; instead, use a container to move them to prevent stress or injury.