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.