Bluefin Notho
Nothobranchius rachovii
Nothobranchiidae
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About
Our other killifish entries all carry the same reassurance: FishBase says "Not a seasonal killifish", so a fish that dies at ten months died of something you can find. This one is the opposite, and it is the reason the word "annual" exists. FishBase's life-cycle record for Nothobranchius rachovii reads, in full, "Annual fish. Matures after 12 weeks." Seriously Fish describes what that means in the floodplain pools of the lower Pungwe and Zambezi: "When its natural habitats become dessicated during the dry season the adult fish die, leaving fertilised eggs encased within the substrate. These are resistant to dessication and remain there until the rains return some 5-6 months later at which point the fry hatch and grow very quickly with sexual maturity reached at around 3 weeks of age." Wikipedia puts the same clock in years: bluefin nothos "mature in about twelve weeks, live for up to a year or year and a half, then die at the end of the breeding season". The sources disagree on how fast maturity arrives — three weeks in Seriously Fish, twelve in Wikipedia and FishBase — and this entry follows the twelve-week figure, which two of the three carry. So read the lifespan field literally. Seriously Fish gives "typical lifespan in the aquarium is 6-12 months"; Aquadiction stretches it to two years. A male that colours up at three months, breeds all summer and fades at ten is not a fish you killed. He is a fish that finished. Keepers who do not know this diagnose a disease that was never there, tear down a working tank, and blame themselves — which is exactly why this page says it out loud. The eggs are the species. They survive dry, and Seriously Fish gives the working numbers: store them at 21.1-25 °C for five to seven months before wetting. The continuity of a line is peat and patience, not a breeding pair, and the hobby tracks that continuity with collection codes — Seriously Fish lists 'Beira 1998' and MOZ 99/1, 99/2 and so on, where MOZ is Mozambique, 99 the year and the last figure the locality. Mix two codes and a line somebody kept separate for twenty years is gone. That matters more than usual here because N. rachovii itself was split: populations to the south and north are now N. pienaari and N. krysanovi, leaving true N. rachovii restricted to the country between the lower Pungwe and Zambezi in eastern Mozambique. The fish is small — 50-55 mm standard length, 6 cm total on FishBase — and the male is one of the most extravagantly coloured freshwater fish there is: alternating light blue and orange-red bars over body and fins, an orange-red head, a caudal fin banded orange then black. Females are plain brown-grey with a light blue reflective spot on each flank scale. It is named for the German aquarist Arthur Rachow (1884-1960).
Care
A single male with two or three females in a quiet, heavily planted tank of their own — Aquadiction is direct that "this species is not suitable for a general community tank", and Wikipedia notes males are aggressive toward other males, so a second male needs a big, heavily decorated tank with real refuges. Seriously Fish says even a pair should get base dimensions of 45 x 30 cm, which is about 40 litres; Wikipedia gives 40-60 litres. Soft, gently acidic water at 20-24 °C — this is a fish kept deliberately cool, and both Seriously Fish and FishBase cap the range at 24 °C. Floating plants, bogwood and catappa leaves; efficient filtration but gentle flow; small, frequent partial water changes. Aquadiction: "tight-fitting lids are a must to prevent this species from jumping out of the tank." Peat moss is not required for day-to-day keeping, only as a spawning medium. FishBase rates the species "very difficult to maintain in aquarium" while Aquadiction calls it beginner-to-intermediate; the honest reading is that keeping one alive is easy and keeping the line alive is not.
Diet
A micropredator. Small live and frozen foods — daphnia, Artemia, moina, cyclops, chopped bloodworm, grindal — two or three times a day. Growth from hatching to breeding size takes about twelve weeks, so there is no room for a thin month.
Tankmate compatibility
Gets along with (162)
Possible with care (168)
Avoid (88)
Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.
Telling males from females
What works for this species, most reliable first.
- Colour and patternStrong · from about 6 months, and only on a settled fish
In rainbowfish, killifish and several barbs the male carries the colour — deeper and more saturated, intensifying further when he displays.
- Extended finsStrong · from about 8 months, and later in a suppressed male
On many cichlids and killifish the male's dorsal and anal fins draw out into trailing points as he matures, while the female's stay rounded.
Also in these lists
Similar species
Same category and the closest water parameters — if this species isn't quite it, start here.
Sold in Lithuania
These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.
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Frequently asked questions
- What tank size does a Bluefin Notho need?
- A Bluefin Notho needs an aquarium of at least 40 litres (10.6 US gallons) with a footprint at least 45 cm (17.7 in) long — for this species, swimming length matters as much as raw volume.
- What water parameters does a Bluefin Notho need?
- Bluefin Notho does best at 20–24 °C (68–75.2 °F), pH 6–7.5 and a general hardness of 3–10 °dGH.
- What group size does a Bluefin Notho need?
- Bluefin Notho is a social species — keep a group of at least 3 so natural behaviour emerges and stress stays low.
- Is the Bluefin Notho suitable for beginners?
- Bluefin Notho is a demanding species best attempted with some experience — it needs stable, closely watched conditions to thrive.