Basis for Listing

The Black Redhorse is at the northern edge of its range in Minnesota. In 1984, it was listed a special concern species, but it was delisted in 1996, when interim surveys revealed additional localities (Schmidt 1993). Since then, the Minnesota DNR (Schmidt 2000) and Pollution Control Agency stream surveys continued to report it but within the species' known and limited distribution in the Zumbro, Root, and Upper Iowa river systems in southeastern Minnesota (Hatch et al). The species was collected once in the Minnesota reach of the Cedar River in the early 1890s and is presumed extirpated; however, it still may occur within the system in northern Iowa (Harlan and Speaker 1987). In the Zumbro system, it has not been reported from Masten Creek since 1974 or from the North Fork Zumbro River or Bear, Cascade, Harkom, and Silver creeks since the early to mid 1980s. In the Root system, the species has not been collected from Spring Valley Creek since 1974. The Black Redhorse has been listed as an endangered species in Wisconsin since 1997 (WI E/T Species List 2013) and a threatened species in Iowa since 2009 (IA E/T Species List 2013). NatureServe (2013) ranks the species as critically imperiled in Kansas, Mississippi, and Wisconsin; imperiled in Illinois, Iowa, New York, and Ontario; and vulnerable in Michigan and Virginia. These factors prompted listing the Black Redhorse a special concern species in Minnesota in 2013.

  Description

The Black Redhorse is a small redhorse that is typically 250-400 mm (9.8-15.7 in.) total length, with a maximum of 450 mm (17.7 in.). Distinguishing characteristics include a slate colored tail fin in life; plicate lower lip that is broad and fleshy, with an obtuse angle; usually 44-47 lateral line scales; usually 10 pelvic fin rays, 12-14 dorsal fin rays, and a narrow caudal peduncle depth that is less than 59% of caudal peduncle's length. Breeding males exhibit fine tubercles on head, body, and fins, with larger tubercles on the lower lobe of the caudal fin; some display a light pinkish lateral stripe. Females have minute tubercles on the head and body but not on the fins (Lyons et al 2006).

  Habitat

The Black Redhorse prefers small- to medium-sized high-gradient streams with permanent flow and a bottom of clean rock or gravel. It occurs in streams where the substrate is comprised of limestone bedrock and spring floods flush silt from pools (Hatch et al).

  Biology / Life History

The Black Redhorse reaches sexual maturity at the smallest size of all Minnesota redhorse. On 16 May 1967 in the Zumbro River, specimens 200 mm (7.9 in.) total length and longer that were collected from riffles and shallow pools were in nuptial condition. In Missouri, spawning trios of two males and one female scattered eggs and provided no parental care. In Illinois, Black Redhorse and Golden Redhorse (M. erythrurum) spawned at the same time in the same stream but in different habitats (Hatch et al).

  Conservation / Management

Populations of Black Redhorse appear stable in the Upper Iowa and Root river systems. However, habitat assessments are recommended in the Zumbro system to identify negative impacts at potentially extirpated localities. Additional research needs include a life history study and genetic analyses of the three river systems where the species occur to determine management as a single or as multiple genetic units. This will also aid in identifying donor populations for future reintroductions of the species to the Zumbro and possibly Cedar river systems.

  Conservation Efforts in Minnesota

In 1992, 1997, and 1998, the Minnesota Nongame Wildlife Program funded stream surveys that reported the species at new localities within its known distribution (Schmidt 2000 and 1993). The recent inception of the Clean Water Legacy Program in Minnesota will eventually yield benefits to the water quality of streams where the species occurs.

  References and Additional Information

Becker, G. C. 1983. The fishes of Wisconsin. University of Wisconsin Press, Madison, Wisconsin. 1052 pp.

Harlan, J. R., E. B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323 pp.

Iowa Department of Natural Resources. 2013. Iowa's Endangered and Threatened Species List [web page]. Iowa Department of Natural Resources, Des Moines. <http://www.iowadnr.gov/Environment/ThreatenedEndangered.aspx>. Accessed 14 May 2013.

Lyons, J., P. C. Hanson, E. A. White. 2006. A photo-based computer system for identifying Wisconsin fishes. Fisheries 31(6):269-275.

NatureServe. 2013. NatureServe Explorer: an online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington Virginia. <http://www.natureserve.org/explorer>. Accessed 14 May 2013.

Phillips, G, L. American Eel Anguilla rostrata (Lesueur, 1817). In J. T. Hatch, G. L. Phillips, K. P. Schmidt, and M. McInerny, editors. The Fishes of Minnesota (in preparation).

Phillips, G. L. Black Redhorse Moxostoma duquesnei (Lesueur). In J. T. Hatch, G. P. Phillips, K. P. Schmidt, M. C. McInerny, and J. C. Underhill, editors. The Fishes of Minnesota (in preparation).

Schmidt, K. P. 1993. Stream survey results for the gravel chub (Erimystax x-punctatus) and black redhorse (Moxostoma duquesnei), in southeastern Minnesota. Final report submitted to the Minnesota Department of Natural Resources. 9+ pp.

Schmidt, K. P. 2000. Stream survey results for the Gravel Chub (Erimystax x-punctatus), Slender Madtom (Noturus exilis), and Bluntnose Darter (Etheostoma chlorosomum) in southeastern Minnesota. Final report submitted to the Minnesota Department of Natural Resources. 14 pp + figures.

Wisconsin Department of Natural Resources. 2013.. Wisconsin's endangered and threatened species list [web page]. Wisconsin Department of Natural Resources, Madison. <http://dnr.wi.gov/topic/endangeredresources/etlist.html>. Accessed 09 May 2013.