Turquoise Killifish

The Turquoise Killifish, Nothobranchius furzeri, is a small annual killifish in the family Nothobranchiidae, native to temporary floodplain pools in Mozambique and Zimbabwe in southeastern Africa. It belongs to a group of African killifish adapted to life in ephemeral water bodies that dry up completely each year. The species has become widely known outside the aquarium hobby as a model organism in biological research because it is the shortest-lived vertebrate known to science, with wild populations often completing their entire life cycle, from hatching to natural death, in just a few months. It remains locally common within suitable temporary-pool habitat in its native range.

Identifying features of Nothobranchius furzeri:

• Compact, deep-bodied fish, typically 4-6 cm as an adult
• Males are vividly colored in turquoise-blue with red-orange speckling and irregular vertical bars across the flanks
• Large, rounded dorsal, anal, and caudal fins, often edged in red or orange in males
• Females are much plainer, pale grey-brown with minimal patterning, typical of the strong sexual dimorphism in Nothobranchius
• Upturned mouth and forward-set eyes typical of surface-dwelling killifish; distinguished from related Nothobranchius species mainly by precise color pattern and native locality

Turquoise Killifish inhabit small, shallow, temporary pools that form in floodplain depressions during the rainy season across parts of Mozambique and Zimbabwe, then dry out completely during the dry season. These pools are typically warm, turbid, and short-lived, sometimes lasting only weeks to a few months before evaporating entirely. The species has no permanent aquatic habitat as an adult; instead, its entire population cycle depends on the pool's temporary existence, with eggs surviving the dry period buried in the mud substrate until the next rains refill the depression.

As an obligate annual species, the Turquoise Killifish undergoes extremely rapid growth, maturing within a few weeks of hatching in order to reproduce before its temporary pool dries out. Adults are solitary, active predators that feed on small aquatic invertebrates such as insect larvae and zooplankton near the pool bottom and surface. Males display vivid coloration and compete for access to females, with spawning occurring repeatedly over the short adult lifespan; eggs are buried in the substrate and enter a resistant diapause state that allows them to survive desiccation until the pool refills. This boom-and-bust life history makes it an important, if short-lived, predator within its temporary wetland ecosystem, and its rapid life cycle has made it a widely studied model species for aging research.