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Brindled madtom

Noturus miurus

What do they look like?

Brindled madtoms are scaleless fishes with eight whisker-like barbels around their mouths, which are used as sensors. Their heads are flattened and round, with a wide mouth and large eyes. Their dorsal and pectoral fins have spiny, venomous rays. Their pectoral fins have small, saw-like notches. Their upper jaw sticks out over their lower jaw slightly. Brindled madtoms are usually a yellow-brown to gray tone. Their sides become lighter and their belly is mostly white. Their whiskers are dusky brown. There is a black spot along the front of the dorsal fin. The anal and adipose fins have a series of small blotches. The caudal fin is wide, dark, and rounded with an un-pigmented band through the center. The adipose fin is either fused with the caudal fin or separated by small notches. Mature fish are approximately 50 to 100 mm long. (Hubbs and Lagler, 2004; Osbourn, 1901; Ross, 2001; Smith, 1979)

  • Sexual Dimorphism
  • male larger
  • Range length
    50 to 130 mm
    1.97 to 5.12 in
  • Average length
    100 mm
    3.94 in

Where do they live?

Brindled madtoms (Noturus miurus) live in North America, including the United States and the lower regions of Ontario. Brindled madtoms are found in major drainages in the eastern and Midwestern United States. Drainages include the basins of the Great Lakes, Illinois River, Mississippi River, and the Gulf of Mexico. These fish can be found from Lake Erie to Mississippi, and as far west as Kansas and Oklahoma. (Froese and Ortanez, 2013; Fuller, 2004; Hubbs and Lagler, 2004; Osbourn, 1901; Ross, 2001; Smith, 1979)

What kind of habitat do they need?

Brindled madtoms live in freshwater streams and lakes and are warm water fish. Streams, pools, and rivers with brindled madtoms are small to medium-sized with sand, mud, gravel, or large rocks at the beds. They are also found in river systems of major drainages. These fish live in the bottom of streams and rivers and in shallower areas of lakes. On average, they are found at a depth of 1.35 meters (4.4 feet). They prefer areas with rocky or sandy beds over clay or mud. These fish usually choose quiet, slow-flowing, clear waters with moderate to dense vegetation and clay-like sand at the banks and beds. They use vegetation and dense habitats for nesting and daytime cover. (Froese and Ortanez, 2013; Hubbs and Lagler, 2004; Osbourn, 1901; Ross, 2001; Smith, 1979)

  • These animals are found in the following types of habitat
  • freshwater
  • Aquatic Biomes
  • benthic
  • lakes and ponds
  • rivers and streams
  • Average depth
    1.35 m
    4.43 ft

How do they grow?

Brindled madtom eggs are about 3.0 mm in diameter and hatch about seven to nine days after being fertilized. About two weeks after being fertilized, their tail begins developing color, dark blotches begin to form, and they are about 14 mm long. In the first two months of development, fish grow to about half their mature size. By 13 to 18 months, males begin to grow larger than females. In most cases, males and females are mature by two years of age. Females can reach maturity as early as one year of age and are born with of their mature eggs. On average, males tend to be larger than females. (Ross, 2001; Smith, 1979)

How do they reproduce?

Males that are ready to breed look somewhat different than normal. They develop thick muscles on the top of their head, protruding lips, and are drabber in color than non-breeding males. Mating occurs in pairs, but females are known to breed with more than one male during the spawning season. Not much is known about how mates are chosen. (Hubbs and Lagler, 2004; Menzel and Raney, 1973; Osbourn, 1901; Ross, 2001; Smith, 1979)

Brindled madtoms spawn once in their lifetime and have a moderate clutch size. Spawning occurs in the spring and summer months in warmer water temperatures. Spawning between males and females occurs in the evening and early morning, when light is low. Following fertilization, nests are formed in a depression that males guard. Brindled madtoms secrete a sticky substance, which allows eggs to be stuck under rocks or other vegetation. Mating couples are together in the nesting area and fertilize the eggs there. Not much is known about their actual spawning process. (Hubbs and Lagler, 2004; Ross, 2001; Smith, 1979)

  • How often does reproduction occur?
    Brindled madtoms breed once per lifetime.
  • Breeding season
    Spawning and fertilization occur in the spring or summer months.
  • Range number of offspring
    50 to 100
  • Average number of offspring
  • Range time to hatching
    7 to 9 days
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    2 years

After fertilizing the eggs, mated pairs of brindled madtoms guard their nests, which are found under rocks or in depressions with some coverage. Most of the guarding is done by the male, although this ends shortly after the eggs hatch. During the short period after hatching, males provide care to their young. (Hubbs and Lagler, 2004; Ross, 2001; Smith, 1979)

  • Parental Investment
  • male parental care
  • pre-hatching/birth
    • protecting
      • male
  • pre-independence
    • provisioning
      • male

How long do they live?

In the wild, brindled madtoms live about three years. They are alive long enough to reach maturity, reproduce, and take care of their young. On average, males live longer than females. (Hubbs and Lagler, 2004; Ross, 2001)

  • Range lifespan
    Status: wild
    5 (high) years
  • Average lifespan
    Status: wild
    3 years
  • Average lifespan
    Status: wild
    3 years

How do they behave?

Brindled madtoms are active during the night. During the day, these fish can be found under shelter or rocks. Brindled madtoms can sometime be found hiding inside cans, bottles, or other debris found in the water. In the early stages of their development, these fish sometimes form schools for protection. (Hubbs and Lagler, 2004; Ross, 2001)

Home Range

There is currently no information available regarding the home range size of brindled madtoms.

How do they communicate with each other?

Not much is known about the communication or perception of brindled madtoms. However, other catfish species are known to have taste buds outside their body, particularly on their whiskers. As bottom feeders, these fish use their whiskers to help them find food. (Atema, 1971; Caprio, 1975)

What do they eat?

Brindled madtoms forage at night, mostly near the substrate. They can sometimes be found eating the small organisms and larvae found near cans or bottles. Brindled madtoms eat plants and smaller animals, although plants make up a smaller part of their diet. Their diet can vary based on what food and resources are available. Like others members of the catfish family, brindled madtoms are bottom feeders, feeding on aquatic insects, small crustaceans, isopods, and vegetation, as well as other small invertebrates. Sensory whiskers around their mouths help them find food. (Hubbs and Lagler, 2004; Ross, 2001)

  • Primary Diet
  • carnivore
    • eats non-insect arthropods
    • eats other marine invertebrates
  • omnivore
  • Animal Foods
  • aquatic crustaceans

What eats them and how do they avoid being eaten?

Brindled madtoms are prey for larger fish in their area including longnose gars. Although, they have venomous spikes on their pectoral spines that help them ward off predators. Brindled madtom eggs are also targeted as a food source for predators. (Burr and Mayden, 1982; Osbourn, 1901; Ross, 2001)

What roles do they have in the ecosystem?

As a predator and prey species, brindled madtoms have a large impact on their ecosystem. In addition, these fish are often parasitized by nematodes, as well as flukes and copepods. (Burr and Mayden, 1982)

Commensal or parasitic species (or larger taxonomic groups) that use this species as a host

Do they cause problems?

There are no known negative effects of brindled madtoms on humans. However, these fish have venomous glands at the base of their pectoral fins, although this only causes a problem if they are handled incorrectly. (Froese and Ortanez, 2013; Fuller, 2004)

  • Ways that these animals might be a problem for humans
  • injures humans

How do they interact with us?

Brindled madtoms are intolerant of polluted water and poor water quality, which makes them a good indicator species. (Smith, 1979)

Are they endangered?

Brindled madtoms are not endangered on a national level and there are currently no national conservation efforts in place for the species. The IUCN lists the species as "Least Concern". However, the state of Michigan lists the species as "special concern". ("Noturus miurus", 2013)

Some more information...


Lauren Drayton (author), University of Michigan-Ann Arbor, Lauren Sallan (editor), University of Michigan-Ann Arbor, Jeff Schaeffer (editor), University of Michigan-Ann Arbor, Leila Siciliano Martina (editor), Animal Diversity Web Staff.


2013. "Noturus miurus" (On-line). International Union for Conservation of Nature and Natural Resources Red List of Threatened Species. Accessed October 17, 2013 at

Atema, J. 1971. Structures and Functions of the Sense of Taste in the Catfish (Ameiurus natalis). Brain, Behavior and Evolution, 4: 273-294.

Burr, B., R. Mayden. 1982. Life History of the Brindled Madtom Noturus miurus in Mill Creek, Illinois. American Midland Naturalist, 107: 25-41.

Caprio, J. 1975. High Sensitivity of Catfish Taste Receptor to Amino Acids. Comparative Biochemistry and Physiology Part A: Physiology, 52:1: 247-251.

Coker, G., C. Portt, C. Mins. 1987. Morphological and Ecological Characteristics of Canadian Freshwater Fishes. Canadian Manuscript Report of Fisheries and Aquatic Sciences, 2554: iv-89.

Froese, R., A. Ortanez. 2013. "Noturus miurus" (On-line). Fish Base. Accessed October 10, 2013 at

Fuller, P. 2004. "Noturus miurus Jordan, 1877" (On-line). USGS. Accessed October 17, 2013 at

Hubbs, C., K. Lagler. 2004. Fishes of the Great Lakes Region. Ann Arbor, MI: University of Michigan Press.

Menzel, B., E. Raney. 1973. Hybrid Madtom Catfish, Noturus gyrinus x Noturus miurus, from Cayuga Lake, New York. American Midland Naturalist, 90: 165-176.

Osbourn, R. 1901. The fishes of Ohio. Columbus: Spahr & Glen.

Ross, S. 2001. Inland Fishes of Mississippi. Jackson, MS: University Press of Mississippi.

Smith, G., J. Taylor, T. Grimshaw. 1981. Ecological Survey of Fishes in the Raisin River Drainage, Michigan. Michigan Acadamician, 13: 275-305.

Smith, P. 1979. The Fishes of Illinois. Illinois: University of Illinois Press.

University of Michigan Museum of ZoologyNational Science Foundation

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Drayton, L. 2014. "Noturus miurus" (On-line), Animal Diversity Web. Accessed December 02, 2023 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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