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
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Water Parameters
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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
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🟢Ideal Tank MatesRachov'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. An aquarium test kit can help you monitor these values.
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. Browse aquarium plant soil options to find the best fit.
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.
Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Rachov's Killifish (Annual).
5 Gallon
10 Gallon Standard
15 Gallon Standard
20 Gallon High
20 Gallon Long
29 Gallon Standard
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Frequently Asked Questions About Rachov's Killifish (Annual)
How big does Rachov's Killifish (Annual) get?
Rachov's Killifish (Annual) (Nothobranchius rachovii) typically reaches a maximum adult size of approximately 6 cm. They have a fusiform body shape and a fast growth rate.
What tank size does Rachov's Killifish (Annual) need?
A minimum aquarium volume of 19 litres and a tank length of at least 30 cm are recommended for Rachov's Killifish (Annual). This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Rachov's Killifish (Annual) need?
Rachov's Killifish (Annual) thrives in freshwater only conditions with a temperature range of 20–26°C, a pH between 6 and 7.5, and a general hardness of 4–12 dGH. A low water flow is preferred.
Is Rachov's Killifish (Annual) peaceful or aggressive?
Rachov's Killifish (Annual) is classified as mostly peaceful with an aggression score of 3 out of 10. They are generally well-suited to peaceful community tanks.
Can Rachov's Killifish (Annual) live alone?
Yes, Rachov's Killifish (Annual) can be kept singly or in a group. They are flexible and adapt well to both setups.
Does Rachov's Killifish (Annual) have any special tank requirements?
Yes. Rachov's Killifish (Annual) benefits from soil / nutrient rich, leaf litter/blackwater, and plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Rachov's Killifish (Annual) need a lid on the tank?
Yes. Rachov's Killifish (Annual) is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Similar Species
Clown Killifish
Epiplatys annulatus
A striking nano killifish resembling a tiny rocket. Native to West African swamps, they have distinct black and yellow vertical bands. They are strictly surface dwellers (top-level) and are non-annual, meaning they live longer than annual killifish (2-3+ years). They are notorious jumpers and require a tight lid.
Gardner's Killifish
Fundulopanchax gardneri
A stunning, semi-annual killifish native to Nigeria and Cameroon. Known for being relatively hardy and an excellent 'beginner' killifish. They are notorious jumpers and require a tightly fitting lid. While they can be kept in community tanks with similarly sized, fast-moving fish, males can be boisterous and territorial.
Norman's Lampeye Killifish
Poropanchax normani
A small, peaceful, schooling killifish native to Central and Western Africa. Named for the bright, iridescent blue/white crescent on the upper part of their eyes, which glows under aquarium lighting. Unlike many killifish, they are not annual and thrive in community setups. They are highly active swimmers and known jumpers, so a tight-fitting lid is required.
Least Killifish (Heterandria)
Heterandria formosa
Despite its common name, the Least Killifish is actually one of the smallest livebearing fish in the world, belonging to the Poeciliidae family, not the killifish family. Native to the southeastern United States, they are incredibly peaceful and perfect for nano tanks. Unlike most livebearers, they exhibit 'superfoetation', meaning females drop 1-2 fry every few days rather than a large single brood.
Golden Wonder Killifish
Aplocheilus lineatus
A large, incredibly hardy, surface-dwelling killifish. The 'Golden Wonder' is a selectively bred bright yellow morph of the wild Striped Panchax. They are notorious predators with surprisingly large, trapdoor-like mouths; they will easily consume neon tetras, guppies, and dwarf shrimp. They are completely peaceful with fish too large to eat, but require a tight-fitting lid as they are expert jumpers.
Florida Flagfish
Jordanella floridae
A robust, deep-bodied killifish native to Florida. Unlike most killifish, they are primarily herbivores and are renowned for their ability to eat Hair Algae and sometimes Black Beard Algae. They are sub-tropical and thrive in unheated aquariums. They can be fin-nippers, especially if underfed or kept with long-finned tank mates.