Nothobranchius geminus / Ifakara TAN 19-01

How to care Nothobranchius geminus

Nothobranchius geminus, specifically the ‘Ifakara TAN 19-01’ strain, is a captivating species of killifish found in the seasonal freshwater pools and temporary waters of the Ifakara region in Tanzania. These killifish belong to the Nothobranchiidae family, and like other species in the genus, they are known for their vibrant coloration, particularly during the breeding season. The males of the Ifakara TAN 19-01 strain show vivid red and orange hues, complemented by striking blue patterns along their fins and bodies, making them a beautiful addition to any specialized aquarium.

This species is short-lived, with an average lifespan of about 1-2 years. Nothobranchius geminus thrives in temporary, seasonal bodies of water that fill during the rainy season and dry up during the dry months. The fish’s unique biological trait is their ability to lay eggs that can withstand desiccation, allowing the eggs to hatch once the pools refill with water after the rains. This adaptation is a key characteristic of killifish species that inhabit ephemeral environments.

In the aquarium, Nothobranchius geminus requires a minimum tank size of 20 gallons (75 liters), and the tank should be well-planted with some hiding spots to simulate their natural environment. The water conditions need to be kept stable with a pH range of 6.5 to 7.5 and a temperature range between 75-85°F (24-29°C). Moderate water hardness, from 8 to 15 dGH, is also important for their well-being. Sudden changes in water conditions can stress these fish, leading to poor health or even death.

As carnivores, Nothobranchius geminus should be fed live foods like brine shrimp, daphnia, and other small invertebrates. While they can accept high-quality commercial pellets and flakes, live foods are essential for maintaining their vibrant colors and overall health. These fish are not particularly challenging to breed in captivity, but because of their short lifespan, it's recommended to breed them early in their life cycle. The males will display intricate courtship behaviors to attract females, and the eggs should be removed and incubated in separate containers to avoid predation by the adults.

For breeding, a ratio of 1 male to 2-3 females is ideal. The males tend to become territorial during breeding, so providing enough space in the tank and ensuring adequate hiding places will help reduce stress and conflict. Once the eggs are laid, they can be collected and incubated until they hatch, typically in several weeks.

Despite being an attractive and fascinating species to keep, Nothobranchius geminus ‘Ifakara TAN 19-01’ is rarely available in the hobbyist market. Acquiring them might require reaching out to specialized breeders or ordering from online sources. If you’re able to obtain them, they are a rewarding species for experienced aquarists, particularly those with an interest in killifish. Their brilliant coloration, fascinating life cycle, and relatively simple care needs make them a great addition to any tank dedicated to unique and rare fish species.