Red Tail Notho Killifish (Nothobranchius guentheri)

The Red Tail Notho Killifish (Nothobranchius guentheri) is a small, stunning freshwater fish native to the seasonal pools and marshes of Zanzibar, East Africa. They are famous for their vibrant colors and unique lifecycle. In the wild, they act as an eco-friendly pest control by eating mosquito larvae.

Physical Profile

Size: They grow to about 2 to 2.5 inches (5–6 cm) in length.

Color: Males have a shimmering blue-green body with a bright red tail fin. Females are smaller and mostly muted brown or gray.

Lifespan: They are annual fish. In the wild, they live for less than a year. In a home aquarium, they usually live for 1 to 2 years.

Tank Setup & Water Parameters

Tank Size: Provide a minimum of 10 gallons (~38 liters).

Water Temperature: Keep the water between 68°F and 76°F (20°C–24°C).

pH Level: Aim for slightly acidic to neutral water, between 6.0 and 7.0.

Tank Cover: A tight-fitting lid is required. These fish are notorious jumpers.

Environment: Use dense live plants, floating plants, and driftwood. This provides shade and hiding spots to reduce stress. Keep the filter flow gentle.

Diet & Feeding

Red Tail Nothos are carnivores. They thrive on small, high-quality proteins.

Best Options: Frozen or live brine shrimp, bloodworms, daphnia, and white mosquito larvae.

Dry Foods: They might accept small flakes or pellets, but dry food should not be their main diet. Live and frozen foods keep their colors bright.

Temperament & Tank Mates

Behavior: Dominant males are highly aggressive toward each other. They will fight for dominance, which can lead to death. They are generally peaceful toward other species.

Grouping: Keep them in a single male-female pair or a harem of one male with multiple females.

Ideal Tank Mates: Small, peaceful community fish like tetras, rasboras, or corydoras catfish. Avoid fin-nippers or large, aggressive fish.