Spikedace

Meda fulgida

Description

The only species in the genus Meda, the spike-dace, Meda fulgida, is a small, slender fish, less than 3 in (7.5 cm) in length. It is characterized by silvery sides and sharp spines in the dorsal and pelvic fins. Breeding males develop a brassy golden color, especially around the head and ventral fins.

Behavior

The highly mobile spikedace has a high reproductive potential but periodically experiences large fluctuations in population size. It spawns in spring and feeds on a range of insects, larvae, and plant matter.

Habitat

The spikedace is found in stream pools and shallow riffles with gravel or rubble substrates and moderate to swift currents. It is tolerant of periodic flooding, which gives it a competitive edge over other native fishes in the watershed. An omnivorous fish, it feeds on tiny animal and plant organisms including detritus, bacteria, filamentous algae, crustaceans, worms, fish, zooplankton, and aquatic insects. Vegetative communities found adjacent to occupied streams include cottonwood dominated riparian communities, ponderosa pine forests, desert shrublands, desert grasslands, and pinyon/ juniper rangelands

Distribution

The spikedace is endemic to the Gila River basin upstream (east) of the city of Phoenix, Arizona. It was once common in the Verde, Aqua Fria, Salt, San Pedro, San Francisco, and Gila Rivers. The historic range may have included the upper San Pedro River in Sonora, Mexico, where habitat no longer exists. The spikedace has been extirpated from most of its historic range in the Gila River basin. It is presently found only in the upper Gila River in New Mexico, and in Aravaipa and Eagle Creeks and the upper Verde River in Arizona. All existing populations are under threat. Land ownership in the remaining sections of occupied river reaches is mixed and includes: private individuals; conservation organizations including The Nature Conservancy (TNC); Arizona and New Mexico State lands; National Park Service (Gila Cliff Dwellings National Monument); U.S. Forest Service (Gila National Forest, Prescott National Forest); and the Bureau of Land Management (BLM) (Aravaipa Canyon Wilderness).

Threats

The distribution and numbers of the spikedace have been greatly reduced by dam construction, artificial channeling of stream beds, water diversion, and groundwater pumping. The San Pedro River in Mexico has been almost totally de-watered by diversion of water to support irrigation agriculture. The species is also threatened by the spread of non-native predators and competitors, such as rainbow trout, smallmouth bass, channel catfish, and red shiner. An additional possible threat to fish is the construction of a major new dam on the mainstream Gila River by the federal Bureau of Reclamation, to control flooding and supply water for irrigation and municipal development. Federal listing of the spikedace aroused opposition from the Southwest New Mexico Industrial Development Corporation, the Hooker Dam Association, the Arizona Cattle Growers Association, the Arizona Mining Association, the Town of Silver City, New Mexico, and the Soil Conservation Service of New Mexico, among others. Many opponents expressed the opinion that the listing of the spikedace was premature or was being used as a pretext to stop dam construction, flood control efforts, and municipal development.The Fish and Wildlife Service (FWS), however, replied that the listing was based on sound biological evidence.

Conservation and Recovery

The BLM owns portions of spikedace habitat on Aravaipa Creek and the Gila River and will assess the effects of its land use strategies—in particular, livestock grazing—on the species. Most spikedace habitat on the Verde River falls within the Prescott National Forest, administered by the Forest Service. The spikedace is offered some protection in New Mexico by its occurrence within the Gila National Forest, Gila Wilderness, and Gila River Research Natural Area. Although the population status has been listed as stable, the FWS has given this species a recovery priority rating of "4C" which means the degree of threat to this species is high and the recovery potential is low. In 1990, a barrier to upstream movement of non-native fishes was announced for Aravaipa Creek in Graham and Pinal Counties, Arizona. The barriers are a multi-agency effort with primary funding and expertise being furnished by the Bureau of Reclamation under their new Enhancement Initiative. The BLM in cooperation with the FWS and Arizona Game and Fish Department, initiated a program to remove exotic fish species (e.g., green sunfish—Lepomis cyanellus, bull-heads—Ictalurus spp.) from stock tanks on BLM lands within the Aravaipa Creek watershed in Arizona. These species need to be removed to prevent their spread into Aravaipa Creek. The 1991 Spikedace Recovery Plan called for the protection of existing populations, the restoration of populations in portions of historic habitat, and the eventual delisting of the species, perhaps by 2011. The plan sets forth mechanisms to obtain information necessary to determine quantitative criteria for describing a spikedace population capable of sustaining itself in perpetuity. Delisting is dependent on the establishment of such populations. Undoubtedly, demise of spikedace has been a result of combined effects of habitat change and introduced fishes. Because relative importance of the two factors has yet to be established, both must be considered in management toward recovery of this threatened species.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P.O. Box 1306
Albuquerque, New Mexico 87103-1306
Telephone: (505) 248-6911
Fax: (505) 248-6915
http://southwest.fws.gov/

References

Barrett, P. J., et al. 1985. "Draft Upper Verde River Aquatic Study." U.S. Fish and Wildlife Service, Arizona Game and Fish Department, and U.S. Bureau of Reclamation.

LaBounty, J. F., and W. L. Minckley. 1972. "NativeFishes of the Upper Gila River System, Mew Mexico." In Symposium on Rare and Endangered Wildlife of the Southwestern United States. New Mexico Department of Game and Fish, Santa Fe.

Propst, D. 1986. "Distribution Status and Biology of the Spikedace in the Gila River Basin, New Mexico." New Mexico Department of Game and Fish, Santa Fe.

U.S. Fish and Wildlife Service. 1986. "Determination of Threatened Status for Spikedace." Federal Register 51(126): 23769-23780.

U.S. Fish and Wildlife Service. 1991. "Spikedace Recovery Plan." U.S. Fish and Wildlife Service, Albuquerque.