Osteogaster melanotaenia

The Green Gold Catfish is a peaceful and social bottom-dweller originating from Colombia, known for its shoaling behavior and making it a great addition to many community aquariums. As a schooling fish, it must be kept in groups to feel secure and prevent stress, allowing its natural, active personality to emerge. You will mostly find them exploring the lower levels of the tank, using their sensitive barbels to sift through the substrate in search of food. Their diet is uncomplicated; being omnivores, they readily accept a variety of sinking foods such as pellets and wafers. For a well-rounded diet, they also appreciate occasional treats of frozen or live foods. Due to their peaceful disposition, they do best with other calm, similarly-sized tank mates. Very large or overly active fish can intimidate them, causing them to hide and miss out on feeding opportunities. A fascinating characteristic of this fish is its ability to occasionally dart to the surface to gulp air, a natural adaptation that helps it in environments with lower oxygen levels. Overall, this catfish is a moderately easy species to care for, requiring stable water conditions and a suitable social group to thrive.

Native to the river systems of Colombia, the Green Gold Catfish inhabits environments with a discernible current. This natural preference translates to an aquarium setting where moderate water flow and high oxygenation are beneficial for its long-term health. Understanding its physiology reveals key care requirements; its fusiform body is well-adapted for navigating water flow, and like other callichthyids, it is protected by rows of bony plates. A notable adaptation is its ability to perform facultative aerial respiration. It possesses a modified intestine that allows it to gulp atmospheric air from the surface, supplementing its oxygen intake. While this is a survival mechanism, frequent gulping in a well-maintained aquarium could indicate low dissolved oxygen levels. For housing, a soft sand or fine, smooth gravel substrate is essential. This protects their delicate barbels, which are crucial sensory organs used to forage for food in the substrate. Sharp or coarse gravel can damage these barbels, leading to infection and an inability to feed properly. Their environment should be enriched with driftwood, caves, and plants to provide security and mimic their natural, sheltered habitats. As a highly social species, their behavior is linked to their group size. In a proper school, they are active and confident, displaying interesting social dynamics. Kept alone or in small numbers, they become shy, stressed, and reclusive. Their diet in the wild consists of insects, small crustaceans, and detritus. In captivity, a varied diet is paramount. High-quality sinking pellets and wafers should be the staple, supplemented regularly with live or frozen foods like daphnia, brine shrimp, and bloodworms to ensure robust health. They are also efficient biofilm consumers, constantly grazing on surfaces throughout the aquarium.

Breeding the Green Gold Catfish is considered moderately difficult but is a rewarding project for the determined aquarist. Success is greatly improved by using a dedicated breeding aquarium. This tank should have clean, mature water, a gentle air-powered sponge filter, and surfaces for egg deposition, such as broad-leaved plants (like Anubias), spawning mops, or even the smooth glass of the tank itself. A bare-bottom tank is often preferred for easy maintenance and egg location. To prepare the fish for spawning, a period of conditioning is essential. This involves feeding the potential breeding group a diet rich in live and frozen foods for several weeks to ensure the females become heavy with eggs and all individuals are in peak health. Sexual dimorphism is subtle but discernible. Females are typically larger, wider, and have a more rounded underbelly compared to the more slender and smaller males. For optimal results, a breeding group with a higher ratio of males to females, such as two or three males per female, is recommended to encourage competition and ensure fertilization. Spawning is often triggered by mimicking natural seasonal changes. Performing a large water change with water that is slightly cooler than the tank's current temperature can simulate rainfall. An increase in flow and aeration can further encourage spawning activity. The reproductive process involves the classic Corydoradinae 'T-position,' where the female presses her mouth against the male's ventral area to receive his milt before depositing her adhesive eggs individually or in small clutches onto a chosen surface. Since the adults will consume the eggs, they should be removed from the breeding tank post-spawning. Alternatively, the eggs can be carefully transferred to a separate hatching container with the same water, gentle aeration, and an optional antifungal treatment. The eggs typically hatch in a few days, and the fry will subsist on their yolk sacs initially. Once they are free-swimming, they must be fed microscopic foods like infusoria or liquid fry food, graduating to newly hatched brine shrimp and finely crushed flakes as they grow. Maintaining pristine water quality through frequent small water changes is critical for the survival of the delicate fry.