Spotfin Chub

Cyprinella monacha

Description

The spotfin chub, Cyprinella (=Hybopsis) monacha, is a small species growing to a maximum size of 3.6 in (9.2 cm) in length. The body is elongate; the mouth inferior; usually there is one pair of minute, terminal labial barbels; scales moderate to somewhat small in size; a distinctive large black spot is present in the caudal region. Juveniles and adult females are olive above with the sides largely silvery and the lower parts white. Large nuptial males have brilliant turquoise-royal blue coloring on the back, side of the head, and along the mid-lateral part of the body; lesser blue is found in at least some fins; all fins are tipped with satiny white during peak development of color. Based on observations and morphological comparisons, it appears that the spotfin chub is a sight feeder, selecting minute insect larvae from clean substrates. An examination of nine specimens revealed that diptera were the dominant food items, comprising 93.4% of the total, with the remaining food items consisting of immature mayflies, stoneflies, and caddisflies.

Behavior

This fish's age at sexual maturity and number of years sexually active are unclear. Its maximum life span is suspected to be less than four years. No observations of reproductive behavior are known. Capture dates of specimens in nuptial condition suggest that spawning occurs in June, possibly beginning in May and extending into July. It is highly unlikely that nests are constructed and eggs are guarded because none of the close relatives of the spotfin chub are known to do so.

Habitat

The spotfin chub inhabits moderate to large streams, 49-230 ft (15-70 m) average width, with a good current, clear water, and cool to warm temperatures. These streams have pools frequently alternating with riffles. The fish has been taken from a wide variety of substrates, although rarely, if ever, from significantly silted substrates.

Distribution

The spotfin chub is restricted to the Tennessee River drainage where it once occurred widely in 12 tributary systems distributed over five states. Presently, this species is known only from the lower North Fork of the Holston River, Virginia and Tennessee; the Emory River System in Cumberland, Fentress, and Morgan Counties, Tennessee; and the upper Little Tennessee River, North Carolina. Efforts are underway to transplant the species to Abrams Creek in Blount County, Tennessee. No quanitiative estimates of its current population density are available. Indices of relative abundance indicate that the spotfin chub was captured with greater frequency prior to about 1950, although it has been generally uncommon or rare since its discovery. This fish was reportedly abundant only in Chickamauga Creek, Georgia, when it was last taken there in 1877.

Threats

The reasons for the decline in some populations are uncertain. Other populations have been adversely affected by such factors as damming, runoff from coal mining operations, municipal and industrial wastes, and siltation.

Conservation and Recovery

Since the exact cause for the decline in some populations is unknown, it is impossible to make meaningful recommendations for these situations. Otherwise, it appears that the best strategy for the conservation of the spotfin chub would be maintain and possibly upgrade habitat in the three river systems containing extant populations.

Contacts

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

Regional Office of Endangered Species
U. S. Fish and Wildlife Service
Federal Building
Ft. Snelling
Twin Cities, Minnesota 55111
http://midwest.fws.gov/

Asheville Ecological Services Field Office
U.S. Fish and Wildlife Service
160 Zillicoa St.
Asheville, North Carolina 28801-1082
Telephone: (828) 258-3939
Fax: (828) 258-5330

References

Freeman, J. C. 1980. "A Quantitative Survey of Fish and Macroinvertebrates of the Holston River Basin: August-September 1973." Report WR (70)-40-80.1. Tennessee Valley Authority, Division of Water Resources.

Jenkins, R. E., and N. M. Burkhead. 1982. "Description, Biology and Distribution of the Spotfin Chub, a Threatened Cyprinid Fish of the Tennessee River Drainage." Report. U. S. Fish and Wildlife Service, Atlanta.

U. S. Fish and Wildlife Service. 1983. "Recovery Plan for the Spotfin Chub." U. S. Fish and Wildlife Service, Atlanta.