The Rachow notobranch or othobranchius rachovii belongs to the family Aplocheilidae. These fish are native to regions of Africa where lakes and ponds evaporate and dry up in the dry season.

Due to its environmental challenges, the nothobranch is commonly known as a killifish or annual. If you’re familiar with gardening, you’ll know that an annual only lives for a single season. They survive in the wild by releasing their pollen to ensure subsequent generations.

Nature has equipped killifish to adapt to their harsh environmental conditions in the same way. This species flowers during the wet season. As the rainy season comes to an end, their habitat begins to disappear. They lay their eggs in the mud before the last of the water evaporates. Then they perish for lack of water. Their eggs, however, survive ensuring the survival of the species. The eggs are baked on dry lake beds until the rains return. Going through this dry period has been shown to be essential for the hatching of the eggs. When the rainy season returns and the ponds and lakes begin to fill up, the eggs hatch and Rachow has triumphed over nature.

Killifish are found in all regions of the world except Northern Europe, Australia, and Antarctica. There are several genera and different species within each of these genera. A small number of species will accumulate, while most are territorial to varying degrees. Each has its own breeding habits and lives determined by its specific environmental conditions. But the Rachow nothobranch killifish is known as an annual because it dies every year. Even in the relative safety of an aquarium, the Rachow notobranch is a victim of its evolution. They only live 1-1.5 years.

These are small fish. A fully grown adult is only about two inches long. They thrive in slightly acidic water; pH 6.5 with a temperature range between 74-79°F. They are considered a peaceful fish, but a heavily planted single species aquarium is recommended.

Rachow’s notobranchs are carnivorous. They will readily eat live foods such as brine shrimp, tubifex, and blood worms. They will also eat freeze-dried, frozen, and meat-based tropical flake foods.

Reproduction of Rachow’s Nothobranch

Breeding these unique fish is done differently than almost any other commercially available fish. Start by laying a 2- to 3-inch layer of peat over your existing substrate. The peat is for spawning. Killifish will bury their eggs in it. Once the eggs are laid on the peat, remove it from the aquarium. Allow the peat to dry, and then place it in a plastic bag. Make sure there is no moisture left in the bag to prevent mold growth. Store the bag for 3-4 months.

After the eggs have gone through an extended period of drying, remove the peat from storage and place it in a breeding tank. Fingerlings can be fed brine from newly hatched shrimp, powdered fry food, or powdered eggs. Allow them to mature enough to keep on their own before introducing them to the adult population in the main tank.