From Aqua Guide, the free encyclopedia
Least Killifish
Heterandria formosa
- Temperature
- 18–26 °C
- pH
- 7 – 8
- Min. tank size
- 40 L
- Lifespan
- 2-3 years
- Diet
- omnivore
- Care level
- easy
| Scientific classification | |
|---|---|
| Scientific Name: | Heterandria formosa |
| Family: | Poeciliidae |
| Origin: | North America (southeastern United States, slow vegetated waters) |
| Care Characteristics | |
| Care Level: | easy |
| Diet: | omnivore |
| Max Size: | 3.00 cm |
| Water Type: | freshwater |
| Temp Group: | subtropical |
| Temperament: | peaceful |
| Min Group: | 6+ together |
| Varieties: | No cultivated strains — this is a wild-type fish and it has escaped the selective breeding that has transformed the guppy, molly and swordtail. Populations vary slightly across the range, and locality-collected stock is sometimes offered by North American native fish enthusiasts, who maintain the species far more than the mainstream trade does. The genus is small and this is the only member in general circulation. Within the wider family, the fish it is most usefully compared with are the other small livebearers: Endler's livebearer, similar in size and considerably more colourful; the dwarf mosquitofish; and the various Heterandria and Poeciliopsis species kept by specialists. Superfetation, its distinguishing reproductive trait, is shared with several other poeciliids including Poeciliopsis and Heterandria species, but it remains uncommon among aquarium fish. For a native North American nano fish in hard water, this species and the pygmy sunfishes are the main options, and this one is much the easier. |
| Lifespan: | 2-3 years |
Quick Tips
- Bioload:Very low
- Min Tank:40 L
- Substrate:Sand or gravel; densely planted with fine-leaved plants
- Plant Safe:Plant-safe
- Filtration:Low (very gentle flow)
Least Killifish (Heterandria formosa) is a species of fish in the family Poeciliidae. It is native to North America (southeastern United States, slow vegetated waters). The least killifish is not a killifish. It is a livebearer, in the family Poeciliidae alongside guppies, mollies and swordtails, and the name is a historical mistake that has stuck. It is one of the smallest fish in the world: males reach about 2 cm, females about 3 cm. It is also native to the southeastern United States, from South Carolina to Florida and along the Gulf coast, which makes it one of very few North American fish in the aquarium trade — and it tolerates cool water accordingly. Its reproductive biology is the interesting part. It practises superfetation: rather than producing a single brood, a female carries embryos at different stages of development simultaneously and releases up to about 40 fry over a period of ten days to two weeks.
Compatibility
- Temperament
- peaceful
- Keep in
- Groups of 6+
- Swims
- middle
- Fin nipper
- No
- Delicate fins
- No
Species similar to Least Killifish
Matched on family, then category, then water type