A stunning annual killifish native to temporary floodplains in East Africa. Because their natural habitats dry up seasonally, they have a short lifespan (usually 8-12 months) and grow incredibly fast. They spawn by diving into soft substrate to bury their eggs, which then require a dry incubation period. Best kept in species-only setups with a soft soil or peat substrate.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
Males are spectacular, featuring vibrant red, blue, and orange patterning. They are highly territorial and aggressive towards other males. It is heavily recommended to keep strictly one male per tank alongside multiple females (a harem).
Differs in 3 traits from base species
Also known as: Show Male, Colorful Notho
Female
Females are slightly smaller and exhibit dull grey or brown coloration. Multiple females should be provided for each male to distribute his constant breeding harassment.
Differs in 3 traits from base species
Also known as: Uncolored, Breeder Female
Rachov's Killifish (Annual) Care Guide Summary
The Rachov's Killifish (Annual), scientifically known as Nothobranchius rachovii, belongs to the Killifish family group. Adults reach a maximum size of approximately 6 cm and have a fusiform body shape with a fast growth rate. Classified as mostly peaceful, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a low level of biological waste.
To thrive, the Rachov's Killifish (Annual) requires a freshwater only aquarium with a minimum volume of 19 litres and a tank length of at least 30 cm. Water temperature should be maintained between 20°C and 26°C, with a pH range of 6–7.5 and a general hardness of 4–12 dGH. A low water flow is preferred.
Due to its specialist needs, the Rachov's Killifish (Annual) is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Male and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Rachov's Killifish (Annual) Habitat Setup
When setting up an aquarium for the Rachov's Killifish (Annual), a low water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a nutrient-rich soil substrate to support planted setups, leaf litter or blackwater tannins to replicate their natural soft-water habitat, and dense planting to provide cover, break sightlines, and reduce stress. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Rachov's Killifish (Annual) Compatibility Notes
Classified as mostly peaceful, the Rachov's Killifish (Annual) is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.
Frequently Asked Questions About Rachov's Killifish (Annual)
How big does Rachov's Killifish (Annual) get?+
What tank size does Rachov's Killifish (Annual) need?+
What water parameters does Rachov's Killifish (Annual) need?+
Is Rachov's Killifish (Annual) peaceful or aggressive?+
Can Rachov's Killifish (Annual) live alone?+
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Similar Species
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