A Review of the Life History and Status of the Desert Pupfish, Cyprinodon macularius
The desert pupfish, Cyprinodon macularius, and its allies were formerly common in sloughs and backwaters of the Gila River in Arizona, and the lower Colorado River in the United States and Mexico. They also were common in shoreline pools and irrigation drains of the Salton Sea in California. In spite of their remarkable tolerance for environmental extremes and high reproductive rate, details of which are summarized herein, the species has undergone a serious decline in numbers. Since the late 1 800s fish have disappeared in association with activities of humans such as dam building, diversions of water, ground-water pumping, and pesticides. They have been further threatened by encroachment of non-native vegetation such as tamarisk, Tamarix spp. The most rapid decline has occurred in recent years in association with introduced fishes. Through pre- dation, aggression, and various behavioral activities that interfere with repro- duction, introduced species have driven pupfish to the brink of extinction. A natural population of reasonable size occurs today only at Quitobaquito Spring in Organ Pipe Cactus National Monument in Arizona. Populations of insecure status, subject to wide fluctuations in density, occur south of Quitobaquito in Rio Sonoyta, Sonora, Mexico, and in San Sebastian Marsh and Salt Creek near the Salton Sea in California. On 31 March 1986 a final rule was published in the Federal Register listing Cyprinodon macularis as an endangered species. Desig- nated critical habitat at San Sebastian Marsh, Imperial County, California at best contains an unstable population of desert pupfish.
Schoenherr, Allan A.
"A Review of the Life History and Status of the Desert Pupfish, Cyprinodon macularius,"
Bulletin of the Southern California Academy of Sciences:
Available at: http://scholar.oxy.edu/scas/vol87/iss3/1