Sicklefin Chub and Sturgeon Chub
The sicklefin and sturgeon chub are members of the Cyprinidae or minnow family.
The sicklefin chub is a small (1.4 to 4.0 inches) slender minnow with extremely small eyes and sickle shaped pectoral fins. Itís back and upper sides are yellowish or tan with silvery reflections. The lower sides and belly are silvery white in color. Itís snout protrudes slightly beyond the mouth with a single pair of maxillary barbels located at the corners of the mouth.
The sturgeon chub is a small (1.5 to 3.8 inches) minnow with a tan to pale green back with fine black specks and silvery sides and belly. It has a long, fleshy snout with a single pair of maxillary barbels located at the corners of the mouth.
Habits and Habitats:
The sicklefin chub and sturgeon chub prefer large, turbid rivers with a diversity of depths and velocities forming braided channels, sand bars, sand flats, and gravel bars. Both are relatively short-lived species with short reproductive cycles.
While the chubs have suffered population declines due to the operations of the six main stem dams built on the Missouri River, they have managed to adapt and remain in substantial numbers where turbidity levels and flows in the river still provide needed habitat conditions.
Sicklefin Chub: The sicklefin chub was historically found in the Lower Yellowstone River, Missouri River, and Mississippi River downstream from the confluence with the Missouri River.
Sturgeon Chub: Sturgeon chub have been collected at or near the same locations where sicklefin chub populations have been documented in the Yellowstone, Missouri, and Mississippi Rivers. They also ascend further upstream in the Yellowstone and Missouri Rivers than the sicklefin chub and have been historically collected in 30 of the larger tributaries to the Yellowstone and Missouri Rivers.
Historic Records: Historic records for the sicklefin chub and sturgeon chub provide an incomplete picture of the range of these fish and their populations prior to construction of dams and other water development activities. Historically, studies designed to document fish populations primarily focused on sport fish, with limited attention given to native minnows. Since the Service was petitioned to list the chubs as endangered, a number of field studies have been conducted to sample chub populations. Data available from recent field investigations provide a more complete record of the locations where sicklefin and sturgeon chub occur.
Sicklefin Chub: Self-sustaining populations of sicklefin chub occur in three locations within the Missouri River basin: above the headwaters of Fort Peck Reservoir in Montana; in the Yellowstone-Missouri River confluence area of Montana and North Dakota; and in the Missouri River from St. Joseph, Missouri to the confluence with the Mississippi River. Data collected by the Missouri Department of Conservation since 1997 indicate that a viable population of sicklefin chub are present in the Middle Mississippi River and in the Wolf Island area of the Lower Mississippi River. The Service estimates sicklefin chub populations currently occupy approximately 54 percent of its historic range in the Missouri River basin.
Sturgeon Chub: Viable populations of sturgeon chub are found at or near the same locations where sicklefin chub populations have been documented. In addition, sturgeon chub populations are currently present in 11 of the 30 tributaries to the Yellowstone and Missouri Rivers where they were historically collected. Sturgeon chub populations currently occupy about 1,155 miles or about 55 percent of its former range in the Missouri River.
FWS Sicklefin Chub Information
Other FWS Sturgeon Chub Information
Fish of the FWS Mountain-Prairie Region
Mountain-Prairie Region Web Site
National FWS Web Site