The population of Devils Hole pupfish at AMFCF was created by taking eggs from Devils Hole. However, eggs are only removed at times of the year when it is unlikely that they would develop into mature adults, such as in the winter. It is thought that egg removal during this time would therefore have the least impact on the population size at Devils Hole. When transferred to AMFCF, the eggs are exposed to anti-fungal, anti-bacterial, and anti-parasite treatments. They are reared in the aquarium until adulthood, at which point they are transferred to the large refuge tank.