Rachovii Killifish
Rachovii Killifish (Nothobranchius rachovii) is one of the most spectacularly colored freshwater fish in the world. Males display an extraordinary combination of vivid blue iridescence and intense red-orange banding — the blue and red are so saturated they appear almost artificial. The Bluefin Notho is the most recognizable Nothobranchius species and a classic of the killifish hobby. All Nothobranchius are annual killifish — they live in seasonal pools that dry up completely each year. The entire adult population dies when the pool dries; survival depends entirely on eggs buried in the substrate that enter diapause and wait out the dry season. In the aquarium, adults typically live 9–12 months. This compressed lifespan is compensated by extraordinary color and rapid maturity — some species are sexually mature within three weeks of hatching.
Feeding & Care Tip: Killifish are carnivores that thrive on a varied diet of frozen and freeze-dried foods. Hikari Frozen or Freeze-Dried Bloodworms, Hikari Frozen or Freeze-Dried Baby Brine Shrimp, and Hikari Frozen Daphnia form the core diet — offer variety rather than relying on a single food. Hikari Micro Pellets are accepted by most killifish as a dry staple. Feed small amounts 2–3 times daily. Varied feeding is especially important for annual species given their compressed lifespan.
Native to Mozambique and Zimbabwe (coastal and lowland seasonal pools). Seasonal pools in the East African coastal plain — shallow depressions that fill during the rainy season and dry completely within months. The water is typically warm, shallow, and moderately hard to hard. In the aquarium, a sandy or peat substrate for egg-laying, a layer of floating plants, and regular feeding are the key requirements.
Keep only one Nothobranchius species per tank — all species in this genus will readily interbreed, producing hybrids that are both less attractive and less valuable than pure-strain fish. Keep one male with two or three females per tank. Males display intensely to females — the full breeding coloration of a displaying male is breathtaking. One of the most spectacularly colored freshwater fish available. Bluefin Notho — iconic in the killifish hobby.
Breeding annual killifish is one of the most fascinating experiences in the hobby. Males display spectacular fin-spreading courtship behaviors to females before driving the female into the substrate to deposit eggs. Eggs are laid in peat moss substrate — after spawning, remove the peat, allow it to dry slightly, then store in a sealed bag or container at room temperature for 6–12 weeks (the 'dry period' that mimics the dry season). After the dry period, wet the peat with soft, slightly acidic water — fry should hatch within 24–48 hours. Fry are immediately free-swimming and large enough to take baby brine shrimp from day one.
Care & Ideal Parameters
| Difficulty | Moderate |
| Temperament | Males territorial — keep 1 male per tank or well-separated groups |
| Typical Adult Size | 2.5 inches (6.3 cm) |
| Min. Group Size | 1 male with 2–3 females — separate from other Nothobranchius |
| Ideal Temp | 72–79°F (22–26°C) |
| Ideal pH | 6.5–7.5 |
| Ideal GH | 5–15 dGH |
| Ideal KH | 2–8 dKH |
| Staple Food | Hikari Micro Pellets |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Bloodworms; Hikari Frozen or Freeze-Dried Baby Brine Shrimp; Hikari Frozen Daphnia |
| Origin | Mozambique and Zimbabwe (coastal and lowland seasonal pools) |
| Notes | Annual killifish — lifespan 9–12 months. Eggs require peat moss and dry period for hatching. all species in this genus will readily interbreed, producing hybrids that are both less attractive and less valuable than pure-strain fish. |