Noturus gyrinus
Tadpole Madtom

Tadpole Madtom

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The natural history of the northwoods



  • Noturus, from the Greek, "back tail", a reference to the connection between the adipose fin and the tail
  • gyrinus, from the Greek, "tadpole"
  • Common Name, from its diminutive size and resemblance to a tadpole
  • Other common names include: Madtom


  • Kingdom Animalia
    • Phylum Chordata, animals with a spinal chord
    • Subphylum Vertebrata, animals with a backbone
      • Superclass Osteichthyes, bony fishes
      • Class Actinopterygii, ray-finned and spiny rayed fishes
      • Subclass Neopterygii
      • Infraclass Teleostei
        • Superorder Ostariophysi
        • Order Siluriformes, the catfishes
          • Family Ictaluridae, North American freshwater catfishes; bullhead catfishes
            • Genus Noturus, the madtoms
  • Noturus is the largest group in the catfish family.


  • A small, elusive catfish
  • Length rarely exceeds 3"-4"
  • Weight
  • Coloration
    • dark olive to brown to sometimes dark gray
    • light beneath
    • conspicuous, very narrow, dark line along side of body
  • Body
    • short and stout
    • smooth, scaleless skin
    • anal fin of 13-15, usually 14, rays
    • pectoral fin equipped with a poison gland at the base. When one is stung or pricked by one of the spines, there is a burning sensation similar to a bee or wasp sting.
    • premaxillary band is bar shaped
  • Head
    • large and fleshy, not flattened
    • upper and lower jaws of equal length
    • four pairs of prominent barbels, usually held pointed forward
    • mouth wide, thick-lipped
    • eyes very small
  • Lifespan
    • most probably mature during their second summer
    • few live beyond their third summer


  • Easily identified as a madtom from its miniature bullhead appearance. Distinguished from the bullheads and other catfish by having its adipose fin continuous with its tail rather than distinctly separate as in its much larger cousins.
  • It is the only madtom native to northern Minnesota and the BWCA


  • Canada, through the midwest to the southern and eastern US.


  • Usually in small, rocky, clear-water streams and riffles, but occasionally at the margins of lakes. Often found among stones, under branches, leaf detritus, or even in old cans.


  • Insects, occasionally algae and other aquatic plants
  • Most active at night



  • Sometimes kept in aquaria by native fish enthusiasts.


  • Female madtoms usually mate several times during the June through July breeding period. Young specimens have been taken in collections in late fall measuring about one inch long. Most individuals probably mature during their second summer and few live beyond their third summer.



Boreal border

Last updated on 15 October 1999