Osteoglossum bicirrhosum, known as the Silver Arowana, is a large, predatory freshwater fish recognized for its metallic sheen and impressive jumping ability.
Overview
Osteoglossum bicirrhosum, commonly known as the Silver Arowana, is a large freshwater fish native to the Amazon Basin in South America. This species is renowned for its elongated body, metallic sheen, and ability to jump out of the water to catch prey. Silver Arowanas can grow up to 60-100 cm (24-39 inches) in captivity and have a lifespan of 10-15 years with proper care. They are powerful swimmers and exhibit predatory behavior, often preying on insects, fish, and even birds that come too close to the water surface.
Tank Requirements
Silver Arowanas require a spacious aquarium due to their size and active nature. A minimum tank size of 500 liters (130 gallons) is recommended to provide adequate swimming space. The ideal water temperature for Silver Arowanas is between 24-28°C (75-82°F), with a pH range of 6.0-7.5 and general hardness (GH) between 3-12 dGH. The tank should have a tight-fitting lid, as Silver Arowanas are known for their ability to jump several feet out of the water. A sand or fine gravel substrate, along with driftwood and large rocks, can help mimic their natural environment. Moderate water flow and strong filtration are essential to maintain water quality.
Feeding and Diet
Silver Arowanas are carnivorous and require a protein-rich diet. In the wild, they feed on fish, insects, amphibians, and even small birds. In captivity, they can be fed a variety of meaty foods, including live or frozen fish, shrimp, crickets, and insects. It is also possible to train them to accept high-quality pellets designed for carnivorous fish. It is important to vary their diet to ensure balanced nutrition and to avoid feeding them large prey that could cause choking or digestive issues.
Care and Maintenance
Osteoglossum bicirrhosum is a hardy species, but they require specific conditions to thrive. Regular water changes of 20-30% every two weeks are necessary to maintain optimal water quality and reduce nitrate levels. The tank should have strong filtration to handle the waste produced by these large fish, but avoid strong currents as they prefer calm waters. Monitoring water parameters, including temperature, pH, and hardness, is crucial to prevent stress and health problems. It is also important to provide a secure tank cover to prevent escapes, as Arowanas are powerful jumpers.
Compatibility
Silver Arowanas are best kept in a species-only tank or with other large, non-aggressive fish. They may eat smaller tank mates or become aggressive if they feel threatened. Suitable tank mates include large catfish, cichlids, and other similarly sized fish that are not overly aggressive. It is important to ensure that all tank inhabitants have enough space and hiding spots to reduce territorial disputes. Avoid keeping them with small or slow-moving fish, as these can easily become prey.
Breeding
Breeding Osteoglossum bicirrhosum in captivity is challenging due to their size and specific breeding requirements. In the wild, they are mouthbrooders, with males carrying the fertilized eggs and fry in their mouths for protection. To breed Silver Arowanas, a very large, well-established tank with precise water conditions is necessary. It is also important to have a compatible pair, which can be difficult to find. Spawning usually occurs during the rainy season, and breeding behavior includes aggressive courtship displays. After spawning, the male will protect the eggs and fry in his mouth until they are free-swimming.