Creek Chub
central mudminnow

What's In a Name?
Creek chub: referring to its abundance in small streams
Semotilus (she-mott´-ill-us) made up from Greek words meaning, "banner" and "spotted" refers to the dorsal fin with its black spot
atromaculatus (atro-mack-you-lah´-tus) means "black spot" in Latin, refers to the black spot at the base of the dorsal fin

Where Do They Live?
Creek chubs occur in all the major drainages of Minnesota. They prefer small to moderate size streams and rivers, as opposed to large rivers and lakes. They are tolerant of turbid (cloudy) water but favor clear to faintly cloudy waters over hard bottoms (gravel, sand, or rubble) rather than soft (silt and mud). They do especially well behind beaver dams. Creek chub commonly live with white suckers, central stonerollers, bluntnose minnows, and bigmouth shiners to name a few species.

How Big Do They Get?
How Long Do They Live?

The creek chub is one of the "Big Three" native Minnesota minnows (the other two are common shiner and hornyhead chub). Males sometimes attain lengths of 250-300 mm (10-12 in) and weigh up to 340 g (12 oz). Females reach 175-200 mm (about 7-8 in) and 225-285 g (about 8-10 oz). Creek chubs can live for 7-8 years although few make it past 5.

What Do They Eat?
Almost all Minnesota fish begin eating small copepods and waterfleas from the water column as larvae. So do creek chubs, but they soon begin foraging in vegetation for larval insects. As they grow, they add a greater variety of aquatic insect larvae, terrestrial (land) insect, and eventually small fish. Because they eat so many different items from different places in their habitat, they are said to be opportunistic feeders.

What Eats Them?
Creek chubs are a main larval item for many predators, such as walleyes, brown trout, northern pike, largemouth bass, and smallmouth bass. Because they often school in lakes, loons, kingfishers, and mergansers also commonly eat them. Little creek chubs even have to watch out for bigger creek chubs. Not too many humans eat creek chubs, although they reportedly are tasty. Some anglers and bait dealers harvest them for bait.

How Do They Reproduce?
Creek chubs spawn from early May in southern Minnesota into July in the north when water temperatures are 13-18° C (55-65° F). In streams, creek chubs excavate (dig out) a pit in gravel beds where there is a moderate current. Using his mouth, the male piles the pebbles upstream of the pit, which forms a ridge as he works downstream. The final product is a ridge up to 30 cm (12 in) long with a shallow pit at its downstream end. Once the "ridge-pit" is built, the male defends it from other male creek chubs and sometimes other species. When a female enters the nest, the male encircles her front with his body and they spawn. The female leaves immediately. She may return or swim to another nest. During each spawning episode a female lays about 25-50 eggs. Her total output in a season may be 1,000-3,000 eggs. The male covers the fertilized eggs after each spawning with some of the gravel from the ridge. There is no further parental care.

Conservation and Management
Creek chubs are among our most common minnows and have no special conservation status. They appear to be fairly tolerant of pollution and showed no tendency to decline during the late 1900s. They are often used as bait for large sportfish, and sometimes end up on the disappointed trout angler's fly or spinner.

Natural History of Minnesota Fishes

Photographs by Konrad P. Schmidt and Donald Biemborn
Text by Nicole Paulson & Jay T. Hatch in cooperation with
the Minnesota Department of Natural Resources' MinnAqua Aquatic Program