Tadpole madtom
Noturus gyrinus (Mitchill, 1817)

member of the Catfish Family (Ictaluridae)

photo by Konrad Schmidt

Stream name, County, State day month year












What's In a Name?
Tadpole madtom: "madtom" refers to this little catfish's habit of sticking people's fingers with their poisonous spines; "tadpole" refers to their bodies looking like a tadpole

Noturus (no-tour´-us) means "back tail" in Greek, referring to the long strip of skin on the back that connects the adipose fin (the fin on the back without fin rays) to the tail fin
gyrinus (jie-wren´-us) means tadpole

    Where Do They Live?
Tadpole madtoms are found throughout Minnesota in streams, river, lakes, and other areas of quiet water over soft bottoms. They often occur in relatively shallow water (1-2 m deep) that may be clear to somewhat turbid (cloudy). They are attracted to underwater vegetation and other types of plant debris, such as tree branches and leaves. This fish often is found with white suckers, central stonerollers, creek chubs, common shiners, and black bullheads.


How Big Do They Get?
How Long Do They Live?
This small fish grows to a maximum length of about 115 mm (4.5 in) and a weight of about 17 g (0.5 oz). The usual life span is 2 years, but very rarely one lives for 3 years.

    What Do They Eat?
This private, bottom-dwelling fish feeds mostly at night when it comes out of its daytime hiding places. It eats mostly aquatic insect larvae, waterfleas and other small crustaceans, and worms. Occasionally it consumes snails, fish eggs, and smaller fish.

What Eats Them?
Many sport fishes, including walleyes, largemouth bass, and large bluegills eat them, especially in lakes. Because of their small size, humans do not eat them.


How Do They Reproduce?
Because tadpole madtoms are so secretive, there is little known about their spawning habits. We believe they spawn in June and July in Minnesota. They do not build a nest. Instead they lay their eggs under submerged objects, like logs, rocks, plant roots, pop cans, etc. Sometimes they use old crayfish burrows. The female lays small numbers of eggs at one time and spawns repeatedly over several weeks. One parent, most likely the male, guards the developing eggs until the young hatch. Females produce clutches (batches of eggs ready at one time) of 80-180 eggs, but we do not know how many clutches they produce in a season. Like all catfish species in Minnesota, tadpole madtoms look like miniature adults by the time they absorb all their yolk.


Conservation and Management
Tadpole madtoms are the most widespread and abundant madtom in Minnesota. They have no special conservation status. Some anglers use them as bait for largemouth bass or walleye early in the fishing season, but they are not used much commercially.




Permission is granted for the non-commercial educational or scientific use of the text and images on this Web document. Please credit the author or authors listed below.

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

This page developed with funds from the
MinnAqua Program (Minnesota Department of Natural Resources, Division of Fisheries)
and the
Sport Fish Restoration Program (Fish and Wildlife Service, US Department of the Interior)

Maintained by Jay T. Hatch
General College and James Ford Bell Museum of Natural History
University of Minnesota, Minneapolis/St. Paul

Last updated 23 October 2002