Cyprinodon pupfish are short-lived, typically reaching an age of no more than a year in the wild, although some may reach as much as three years.
Especially those from habitats that experience major environmental fluctuations (for example, large variations in temperature) rapidly reach maturity and are already able to breed when 1–1.5 month old.
Despite some species' ability to survive in a wide temperature range, their requirements for breeding often are much more specific.
For example, although some populations of C. nevadensis can live in water that ranges between 2 and 44 °C (36–111 °F), they only breed from 24 to 30 °C (75–86 °F).
However, there are exceptions like C. rubrofluviatilis that will breed at a relative wide range from 13 to 34 °C (55–93 °F).
Consequently, pupfish living in stable habitats breed year-round, but those in more seasonal habitats generally only at certain times of the year where the conditions are optimal.
When breeding, males assume a relatively bright nuptial coloration.

There are two primary breeding strategies: In species of small isolated habitats like springs, each large male (or medium-sized male, if large males are absent) defends a territory and displays to visiting females that will lay their eggs inside the territory.
In at least some species, small males will attempt to fertilize eggs by sneaking into a territory of a larger male.
Once deposited, neither sex cares for the eggs, although they do get a level of protection by being inside the territory of a male.
A male will attempt to attract several females to lay their eggs in his territory and a female may lay eggs in the territories of several males.
Another breeding strategy is used by species that inhabit rivers.
Here the males do not maintain a territory and groups of pupfish gather to breed.
A male typically will lead a female to the edge of the group to spawn, although on occasion it may occur in the middle of the group.
The eggs of Cyprinodon pupfish are adhesive and stick to the substrate, or they are covered in sand.
Cyprinodon pupfish are short-lived, typically reaching an age of no more than a year in the wild, although some may reach as much as three years. Especially those from habitats that experience major environmental fluctuations (for example, large variations in temperature) rapidly reach maturity and are already able to breed when 1–1.5 month old. Despite some species' ability to survive in a wide temperature range, their requirements for breeding often are much more specific. For example, although some populations of C. nevadensis can live in water that ranges between 2 and 44 °C (36–111 °F), they only breed from 24 to 30 °C (75–86 °F). However, there are exceptions like C. rubrofluviatilis that will breed at a relative wide range from 13 to 34 °C (55–93 °F). Consequently, pupfish living in stable habitats breed year-round, but those in more seasonal habitats generally only at certain times of the year where the conditions are optimal. When breeding, males assume a relatively bright nuptial coloration.
There are two primary breeding strategies: In species of small isolated habitats like springs, each large male (or medium-sized male, if large males are absent) defends a territory and displays to visiting females that will lay their eggs inside the territory. In at least some species, small males will attempt to fertilize eggs by sneaking into a territory of a larger male. Once deposited, neither sex cares for the eggs, although they do get a level of protection by being inside the territory of a male. A male will attempt to attract several females to lay their eggs in his territory and a female may lay eggs in the territories of several males. Another breeding strategy is used by species that inhabit rivers. Here the males do not maintain a territory and groups of pupfish gather to breed. A male typically will lead a female to the edge of the group to spawn, although on occasion it may occur in the middle of the group. The eggs of Cyprinodon pupfish are adhesive and stick to the substrate, or they are covered in sand.
Cyprinodon