Gunther’s Killifish – Cuboid Nature Aquarium

Gunther’s Killifish

Gunther’s Killifish(Nothobranchius guentheri) Males develop vivid red body coloration with blue iridescent scale markings and striking red and blue fin patterning. Named for the 19th century ichthyologist Albert Günther of the British Museum. AllNothobranchiusare 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, andHikari Frozen Daphniaform the core diet — offer variety rather than relying on a single food.Hikari Micro Pelletsare 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 Zanzibar Island and coastal Tanzania. 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 oneNothobranchiusspecies 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. Named for ichthyologist Albert Günther. Originally described from Zanzibar.

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