Desert Pupfish Gila Topminnow
Restoring Two of Arizona’s Most Imperiled Fish
The Gila topminnow and desert pupfish are two of 36 species that historically inhabited Arizona’s waters prior to European-American settlement. The Gila topminnow is a small, short-lived fish that bears live young. Although a topminnow’s lifespan is generally less than a year, they reproduce frequently and are capable of producing multiple broods per month. Females are able to carry multiple broods of young at different stages of development simultaneously. Mature adults are sexually dimorphic (males and females look different) and are capable of reproducing year-round, though generally, the breeding season starts in January and continues through August. Topminnow, as their name indicates, spend the majority of their time close to the water’s surface. They feed on detritus (decayed matter), plants, small crustaceans, and small invertebrates including mosquito larvae.
The pupfish, named so because of the aggressive behavior exhibited by the male during the mating season, is a short, stout-bodied fish that exudes personality. Desert pupfish, like Gila topminnow, have relatively short life spans of approximately 1-2 years. Pupfish spawn during the warmest months, typically April through October. The female, attracted by the male’s bright colors and behavior, enters the male’s territory and pairs with him. Although only one egg is released during a single session, a pair can spawn multiple times and female pupfish can release up to 800 eggs during a single breeding season. Pupfish feed on detritus, algae, aquatic invertebrates, and crustaceans.
Topminnow and desert pupfish historically occupied springs, marshes, cienegas, small, slow-flowing streams, and margins and backwaters of slow-moving rivers, below 5,200 feet elevation. The two species prefer shallow, warm water with complex habitat providing suitable cover and forage opportunities. Historically, topminnow were the most abundant fish species in the entire Gila River basin, occupying river systems from western New Mexico to southern and western Arizona. Desert pupfish, were not as common and widespread, occurring in portions of the lower Gila River basin, including the Salt, San Pedro, and Santa Cruz rivers. They also occurred along much of the lower Colorado River, from the Colorado River delta in the Gulf of California to current day Needles, California.
Despite their once broad distribution, these fish currently inhabit a fraction of their historic range. With the arrival of settlers, wells were drilled and cienegas drained to minimize malaria and create farming habitat, while aggressive, invading nonnative fish and aquatic species were introduced into the remaining habitat. As a result of this habitat loss and degradation, topminnow and pupfish populations rapidly decreased. By the early 1900s, pupfish no longer existed in the wild in Arizona (with the exception of Quitoboquito), and Gila topminnow were reduced to only 14 locations.
As a result of the rapidly declining topminnow populations, and the likelihood of complete extinction, the Gila topminnow was federally listed as endangered in 1967. Two decades later, the desert pupfish was federally listed as endangered in 1986. Designating these species as endangered provided funding and defined actions or tools to be used for both topminnow and pupfish recovery. A recovery plan was drafted and accepted for each species.
Using recommendations from the species' recovery plans, the Arizona Game and Fish Department and its partners are taking steps to increase populations of these species in hopes of delisting them in the future. Partner organizations include the U.S. Fish and Wildlife Service; U.S. Forest Service; Bureau of Land Management; U.S. Bureau of Reclamation; The Nature Conservancy; Native American tribes; state, county, and city agencies; private landowners, leasees and permittees; universities; non-governmental organizations; and, volunteers.
Goal: Recover the species to allow removal from the Endangered Species list.
The Department will accomplish this by focusing on the three main parts of recovery: 1) protecting the genetic integrity of the remaining topminnow and pupfish populations, 2) create self-sustaining topminnow and pupfish populations within their historic range and habitat, and 3) utilize natural and semi-natural habitat to establish populations that may require additional human intervention to persist.
Tools: The Gila Topminnow and Desert Pupfish Recovery Plans and Safe Harbor Agreement. For more information, visit www.fws.gov [PDF, 306kb].
Progress: The Arizona Game and Fish Department and its partners have stocked Gila topminnow and desert pupfish into nearly fifty locations. Despite the seemingly high stocking numbers, site success, species persistence and survival remains low. However, biologists are confident that with continued conservation efforts and the use of tools like Safe Harbor Agreements, Gila topminnow and desert pupfish will be down-listed to a threatened status in the future.
For additional information or to get involved in native fish conservation efforts, contact:
Arizona Game and Fish Department, Nongame Branch
5000 W Carefree Highway
Phoenix, Arizona 85086