Montana Field Guide

The sicklefin chub is apparently one of the rarest fishes in Montana. It is a native form first collected in 1979 and to date has only been found at three sites. Because it is rare, it is a Montana Fish of Special Concern. Its general habitat and distribution is much like that of the sturgeon chub. The sicklefin chub is found in large, turbid streams in the plains region of Montana. This species is very similar in appearance to the sturgeon chub except that its pectoral fins are strikingly long. The life history features and maximum size of the sicklefin chub are similar to those of the sturgeon chub.

Sicklefin chub are light brown on the back and upper sides and silvery-white below. There is a conspicuous barbel at each corner of the mouth.

Sicklefin chub are strictly confined to the main channels of large, turbid rivers where they live in a strong current over a bottom of sand or fine gravel (Pflieger 1975).

Unlike the sturgeon chub, all of the Montana captures have been from only the Missouri and Yellowstone rivers, indicating a strong preference for large turbid rivers (AFS website 2003).

The species is probably a bottom feeder which locates its food primarily by taste (Pflieger 1975).

Montana apparently marks the upstream limit of the sicklefin chub's range (Holton 1980, 1990).

The species reaches a maximum age of 4 years and generally becomes sexually mature at the age of 2. Spawning occurs in main channel areas of large, turbid rivers which they inhabit. The spawning period is in the summer months and probably occurs over a wide time span, similar to other big river species. Although sympatric, there is no information that suggests this species hybridizes with the other member of its genus, the sturgeon chub (Macrhybopsis gelida) (AFS website 2003).

The management of this species should involve routine monitoring (once every 2 to 3 years) of existing populations. The program should be designed to monitor population trends, range expansion or losses and collect additional information on life history and ecology. This could be conducted while sampling for other species. The lack of proper monitoring of these populations could lead to their demise by virtue of not recognizing if and when they are in jeopardy of becoming extirpated by any artificial or natural entity. Recommendations for operating reservoir and irrigation projects should be developed for improving and maintaining sicklefin chub populations and habitats in Montana (AFS website 2003).