Plants and Animals

Notropis dorsalis Bigmouth shiner

Key Characteristics

Attaining a maximum length of about 3 inches, this small minnow has a grayish to olive-yellow back, pale silver belly and silver sides with a dark stripe down the center, running the length of the body. The head is large with a flattened ventral surface, creating a blunt triangular shape when viewed from the side. The scales nearest the head have a crowded appearance. Extending below the large, black eyes, the wide mouth of this species is overhung by its snout. As is characteristic of all native minnows, the bigmouth shiner has a single, translucent dorsal fin with less than 10 soft rays.

Status and Rank

US Status: No Status/Not Listed
State Status: T - Threatened (legally protected)
Global Rank: G5 - Secure
State Rank: S2 - Imperiled


CountyNumber of OccurrencesYear Last Observed
Allegan 14 1960
Baraga 7 1999
Barry 1 1951
Clare 2 2001
Houghton 6 1956
Ionia 1 1927
Kent 5 1997
Lake 1 1953
Manistee 1 1951
Mecosta 3 1927
Missaukee 6 2001
Montcalm 3 1927
Muskegon 2 1940
Newaygo 11 1997
Oceana 1 1997
Ontonagon 1 2007
Osceola 2 1996
Ottawa 3 1997
Roscommon 3 1922
Schoolcraft 1 1957
Wexford 1 1990

Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


The bigmouth shiner seems to prefer moderately fast moving creeks and streams less than 3 feet deep, but is occasionally found in larger rivers as well (McCulloch 2003).

Natural Community Types

  • Headwater stream (1st-2nd order), riffle
  • Headwater stream (1st-2nd order), pool
  • Headwater stream (1st-2nd order), run
  • Mainstem stream (3rd-4th order), run
  • Mainstem stream (3rd-4th order), riffle
  • River (5th-6th order), run
  • River (5th-6th order), riffle

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Management Recommendations

Efforts to prevent streambank erosion and other means of sedimentation will benefit this species, as it is intolerant of highly turbid waters (McCulloch 2003). Competition with the invasive silverjaw minnow, which has similar habitat requirements, has resulted in the shrinking of bigmouth shiner distribution in Ohio (Trautman 1981). Unlike many fish species, the bigmouth shiner has shown the ability to thrive and increase its numbers in channelized waterways (Scarnecchia 1988). General management of native stream fish calls for water quality improvement through reductions in point and non-point source pollution, maintaining healthy habitat structure by limiting impoundments, dredging and other types of detrimental construction, expanding research and promoting awareness.

Active Period

Spawning from third week of May to second week of August

Survey Methods

Surveys for minnow species are generally conducted throughout the the late spring and summer using electroshockers or seine nets. Adult minnows can also be surveyed with small mesh fyke nets. In early autumn, night time electrofishing surveys for both adult and juvenile fish are used (Schneider et al. 2000).


Survey Period: From first week of May to first week of September

Time of Day: Daytime
Survey Method Comment: Adult fish

Survey Period: From second week of September to second week of October

Time of Day: Night
Survey Method Comment: Adult and juvenile fish


Survey Period: From first week of May to first week of September

Time of Day: Daytime
Survey Method Comment: Adult and juvenile fish

Trap or fyke nets

Survey Period: From first week of May to first week of September

Time of Day: Daytime
Survey Method Comment: Small mesh, adult fish only


Survey References

  • Schneider, J.C., G.R. Alexander, and J.W. Merna. 2000. Modules for Lake and Stream Surveys. Chapter 2. In: Schneider, J.C. (ed.). 2000. Manual of fisheries survey methods II: with periodic updates. Michigan Department of Natural Resources, Fisheries Special Report 25, Ann Arbor.

Technical References

  • McCulloch, B.R. 2003. Update COSEWIC status report on the bigmouth shiner Notropis dorsalis in Canada, in COSEWIC assessment and update status report on the bigmouth shiner Notropis dorsalis in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 20 pp.
  • Phillips, G.L., W.D. Schmid, J.C. Underhill. 1982. Fishes of the Minnesota Region. University of Minnesota Press, Minneapolis. 248 pp.
  • Scarnecchia, D.L. 1988. The importance of streamlining in influencing fish community structure in channelized and unchannelized reaches of a prairie stream. Regulated Rivers: Research and Management 2: 155-66.
  • Scott, W.B. and E.J. Crossman. 1973. Freshwater fishes of Canada. Bulletin 184, Fisheries Research Board of Canada, Ottawa. 966pp.
  • Trautman, M.B. 1981. The Fishes of Ohio. Ohio State University Press, Columbus. 782pp.