Yellowfin Madtom

Noturus flavipinnis

Description

The yellowfin madtom, Noturus flavipinnis, is a small, elongated catfish that grows to a maximum length of about 3.6 in (9 cm). It has large eyes, a rounded caudal fin, and a dark spot on the upper sides just in front of the tail fin. The body, especially the fins, are tinged with yellow.

Behavior

Very little is known of the yellowfin madtom's reproductive behavior since few specimens have been collected during spawning. However, it is thought they spawn in the late spring, and like other madtoms, deposit their eggs on the underside of stones upstream from the usual habitat. The yellowfin madtom feeds on a variety of aquatic insects, and is most active at night.

Habitat

This small catfish inhabits moderately flowing streams with clean, warm water, adequate plant cover, and little siltation. At night, the nocturnal yellowfin madtom is likely to be found on the streambed away from the banks and riffle areas.

Distribution

The yellowfin madtom was probably widely distributed throughout many of the lower streams of the Tennessee River basin above Chattanooga, Tennessee at one time. It has been collected from six streams—Chickamauga Creek, Hines Creek, the North Fork of the Holston River, Cooper Creek, Powell River, and Citico Creek.

Only three known populations remain in Citico Creek (Monroe County) and Powell River (Hancock County) in Tennessee, and Copper Creek (Scott and Russell counties) in Virginia. An experimental population has been established on the Holston River in Tennessee and Virginia.

In 1990, the population trend for the yellowfin madtom appeared to be a steep downward slope. Cooperating conservation groups therefore decided to take only one yellowfin nest from Citico Creek in 1991; to stock all of the juveniles that were reared back into Citico Creek (68 total); and not take any nests from Citico Creek in 1992. In 1993, the yellowfin madtom population index suggested a strong upward trend. Two nests were collected, and all 113 of the juveniles produced were released back into Citico Creek. At the time of the 1994 survey, the number of yellowfins looked promising, indicating a continuing trend toward successful recovery.

Threats

Three of the six historical populations have been lost because of water impoundment and pollution. At present, the Powell River site is threatened by coal siltation. Even if all coal mining stopped now, previously deposited siltation would continue to threaten yellowfin madtom habitat. The Citico Creek locality in the Cherokee National Forest is probably the most secure, but faces some danger of acid contamination because of the nature of shale strata in the region.

Conservation and Recovery

The U. S. Fish and Wildlife Service (FWS) has finalized plans to establish a "non-essential experimental" population on the North Fork of the Holston River in Washington County, Tennessee. A non-essential experimental population is one whose survival is not considered essential to the survival of the species. This designation allows scientists more management flexibility. Authority over the experiment is assigned to the state of Virginia.

Since the early 1980s, biologists with the Cherokee National Forest have studied and monitored the populations of the fish in cooperation with the University of Tennessee, Tennessee Wildlife Resources Agency, U.S. Fish and Wildlife Service, Great Smoky Mountains National Park, and a private organization, Conservation Fisheries, Inc. Research on the life histories of the species was funded by these cooperators. Annual population monitoring began in 1986. Collection of nests with eggs, followed by captive propagation in aquariums, came next.

Although successful spawning in aquariums had not been achieved as of 1994, wild-collected eggs have hatched in captivity, and fry have been reared to a size large enough for release. The fry are being stocked into Abrams Creek in the Great Smoky Mountains, another stream in which both species are believed to have occurred. If populations can be established in Abrams Creek, these species will be brought a step back from the brink of extinction.

Since the late 1980s, the FWS has been working with the National Park Service to reintroduce the yellowfin madtom in Abrams Creek within the Great Smoky Mountains National Park (Blount County, Tennessee). When this population is established, FWS will turn its efforts to the Holston River reintroduction.

During 1989-1991, when the yellowfin madtom population index was so low, it was comforting to know that some individuals were being held in an experimental captive breeding program. Full recovery of this species and several others in the southern Appalachian Mountains will be assured only by habitat restoration, successful captive breeding programs, and the establishment of reintroduced populations.

Contact

U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

References

Bauer, B. H., G. L. Denkins, and D. A. Etnier. 1983."Discovery of Noturus baileyi and N. flavipinnis in Citico Creek, Little Tennessee River System." Copeia 1983:558-560.

Taylor, W. R., R. E. Jenkins, and E. A. Lachner. 1971."Rediscovery and Description of the Ictalurid Catfish, Noturus flavipinnis. " Proceedings of the Biological Society of Washington 83:469-476.

U.S. Fish and Wildlife Service. 1983. "Yellowfin Madtom Recovery Plan." U.S. Fish and Wildlife Service, Atlanta.