Umbra limi
Central Mudminnow

Central Mudminnow

Flora, fauna, earth, and sky...
The natural history of the northwoods



  • Umbra, from the Latin, "shade"
  • limi, from the Latin, "mud"
  • Common Name from its preference for muddy bottom habitats and its habit of burrowing into the mud for shelter and escape. Despite name, it is not a minnow, but a small relative of the pike.
  • Other common names include: Dogfish, Mudfish, Mississippi Mud Minnow, Mud Minnow, Western Mudminnow


  • 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 Protacanthopterygii
        • Order Esociformes, the pikes and mudminnows
          • Family Esocidae, the pikes and pickerels
            • Genus Umbra, the mudminnows
  • Some place the mudminnows in their own family, Umbridae


  • A hardy, robust-bodied fish
  • Length 2"-7",
    • maximum of 5"-6"
    • average length of about 2" or slightly larger.
  • Coloration
    • upper part of the body olive-brown, mottled throughout
    • belly yellow to white
    • fins brownish
    • up to 14 indistinct dark brown vertical bars on its sides
    • a prominent dark vertical bar at the base of the tail
  • Body
    • large scales over the head and body
    • all of the fins are rounded on the edges
    • short dorsal fin of 13-15 soft rays
    • pelvic fin of 6-7 rays
    • pectoral fin of 14-16 rays
    • anal fin of 7-9 rays
    • tail rounded
  • Head
    • snout short and blunt
    • mouth terminal, with a slightly protruding lower jaw
    • gill rakers short and stout, numbering 13-15
  • Lifespan up to 9 years


  • Identifiable as a Mudminnow by:
    • short, blunt snout
    • single, rounded dorsal fin
    • rounded tail fin
  • The only Mudminnow of the North Country


  • St. Lawrence/Great Lakes, Hudson Bay (Red River), and Mississippi River basins from Quebec to Manitoba and south to central Ohio, western Tennessee, and northeastern Arkansas; also the Hudson River drainage (Atlantic Slope), New York.
  • Isolated populations in Missouri River drainage of east central South Dakota and western Iowa


  • Moderate to heavily vegetated portions of small streams, ponds, lakes, and marshes, over a bottom of mud or thick muck. Avoids fast-moving waters.
  • Well adapted to the cold north, surviving in cold bogs and in ponds that are mostly frozen in winter. Survives short dry periods by burrowing in the mud.
  • Has both gas-absorbing and secreting organs in the swim bladder. When oxygen levels are insufficient in the water, it simply gulps air from the surface.
  • Very tolerant of harsh conditions, including low oxygen levels and high water temperatures.


  • Carnivorous bottom feeder, mainly consuming small snails, crustaceans, insect larvae, fish, plants and algae.
  • Eaten in turn by Northern Pike (Esox lucius) and sunfishes, as well as birds, muskrats, and foxes.



  • Used extensively as a bait minnow where plentiful. Preferred bait for many walleye anglers because of its hardiness.
  • Good aquarium fish because of their hardiness and tolerance of low dissolved oxygen levels in water.


  • Spawning begins in April at water temperatures of 55º-60º F. Shallow backwater areas subject to overflow provide excellent breeding grounds, with a rise in water temperature providing the stimuli for spawning.
  • Pairs move to shallow water, where the female deposits 200 to 2,000 adhesive eggs, deposited singly and directly in aquatic vegetation. No parental care is given the eggs, which hatch in about a week, or the young.


  • Will bury itself in mud to avoid capture.
  • Able to utilize atmospheric oxygen.


Boreal border

Last updated on 14 November 1999