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Montana Field Guides

Longnose Dace - Rhinichthys cataractae

Native Species

Global Rank: G5
State Rank: S5
(see State Rank Reason below)

Agency Status


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State Rank Reason (see State Rank above)
Currently ranked a S5 because it is common, widespread, and abundant (although it may be rare in parts of its range). Not vulnerable in most of its range.
General Description
The longnose dace has the most widespread distribution of all fish in Montana. It is found throughout all three of our major drainages. It is very adaptable, inhabiting almost every conceivable habitat: muddy and warm, clear and cold, streams and lakes. The largest longnose dace are about 6 inches long. They are well-adapted for living on the bottom of fast-flowing streams among the stones. Longnose dace eat mostly immature aquatic insects. They are probably one of the most important forage minnows for Montana's larger predatory game fish.

Diagnostic Characteristics
Back olive to black, shading to white or yellow underneath. Sides may have dark blotches. Breeding males have reddish orange on head and fins. Juveniles have a black midside stripe starting at the tip of the snout and ending at the base of the tail fin. Adults often have a dark stripe ahead of eye. Small barbel at each corner of mouth.

Species Range
Montana Range


Western Hemisphere Range


Observations in Montana Natural Heritage Program Database
Number of Observations: 2112

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Habitat variable. Found in lakes, streams, springs (Brown 1971). Preferred habitat is riffles with a rocky substrate (Morris et al. 1981, Elser et al. 1980).

Food Habits
Eats mostly immature aquatic insects picked off the rocks. Small amounts of algae and a few fish eggs are also eaten (Brown 1971).

Showed a preference for main channel border habitat type in middle Missouri River study (Gardner and Berg 1980). Have declined after formation of Lake Koocanusa on the Kootenai River (Huston et al. 1984).

Reproductive Characteristics
Sexually mature probably in 3 yrs. Spawns late spring or early summer at 53 degrees F. in shallow riffle areas over gravel beds (Brown 1971). Middle Missouri River populations spawn early June to latter part of July. Peak in late June (Berg 1981).

  • Literature Cited AboveLegend:   View Online Publication
    • Berg, R.K. 1981. Fish populations of the wild and scenic Missouri River, Montana. Montana Department of Fish, Wildlife and Parks. 242 p.
    • Brown, C.J.D. 1971. Fishes of Montana. Montana State University, Bozeman, MT. 207 pp.
    • Elser A., C. Clancy, L. Morris, M. Georges 1980 (revised). Aquatic habitat inventory of the Beaver Creek drainage and selected tributaries of the Yellowstone River. BLM report: YS-512-CT7-74. 86 pp.
    • Gardner, W.M. and R.K. Berg. 1980. An analysis of the instream flow requirements for selected fishes in the Wild and Scenic portion of the Missouri River. Mt Dept. of Fish, Wildlife and Parks. 50 pp.
    • Huston J.E., P. Hamlin; B. May 1937-; Montana. Dept. of Fish, Wildlife, and Parks.; United States. Army. Corps of Engineers. Seattle District. 1984
    • Morris, L., T. Hightower, and A. Elser. 1981. An aquatic resources assessment of selected streams in the Lower Yellowstone River Basin. Bureau of Land Management report: YA-512-CT9-52. 151 pp.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Bahn, L. 2007. An assessment of losses of native fish to irrigation diversions on selected tributaries of the Bitterroot River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 118 p.
    • Barfoot, C.A. 1993. Longitudinal distribution of fishes and habitat in Little Beaver Creek, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 66 p.
    • Clancey, C.G. 1978. The fish and aquatic invertebrates in Sarpy Creek, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 54 p.
    • Clothier, W.D. 1952. Fish loss and movement in irrigation diversions from the West Gallatin River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 32 p.
    • Urban, Larry, 2002, Biological Resources Report: Wagner Pit Wetland Restoration Site. Proj. No. STPX 56(50) CN 4645. February 23, 2002. In Wgner Pit WS#13 Upper Yellowstone, Yellowstone County. Fin. Dist. 5 AdminDist 5.
    • Werdon, S.J. 1992. Population status and characteristics of Macrhybopsis gelida, Platygobio gracilis and Rhinichthys cataractae in the Missouri River Basin. Masters thesis. South Dakota State University, Brookings, SD. 55 pp.
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Citation for data on this website:
Longnose Dace — Rhinichthys cataractae.  Montana Field Guide.  .  Retrieved on , from