Etheostoma nigrum
    Johnny Darter

Johnny Darter

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The natural history of the northwoods

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Name:

  • Etheostoma, from the Greek, etheo, "filter", and stoma, "mouth"
  • nigrum, from the Latin, "black"
  • Common Name,

Taxonomy:

  • 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 Acanthopterygii,
        • Order Perciformes, the perch-like fishes
        • Suborder Percoidei
          • Family Percidae, the true perches
            • Genus Etheostoma

Description:

  • A common midwestern darter
  • Length up to 2½"
  • Weight
  • Color
    • sides tan/brown with numerous, conspicuous w-shaped markings
  • Body
    • dorsal fin of 12 rays
    • anal fin of 8 rays
    • about 50 scales along the lateral line
    • breast and cheeks scaleless
  • Head
    • somewhat "bug-eyed"

Identification:

  • Small size and prominent, double dorsal fin distinguishes as a darter.
  • Best distinguished from other darters by the dark "W" markings on side

Distribution:

  • Southern Canada through the upper midwest, south to Arkansas and Florida.
  • Common to some of the larger streams of the BWCA, such as the Kawishiwi.

Habitat:

  • Preference quite diverse. Found in streams of various size, gradient, substrate, and clarity. Of all the darter species, the most tolerant of diverse conditions.
  • Not a riffle species; frequently encountered in small to medium-sized streams of moderate clarity, in pools over sand or solid bedrock.

Food:

  • Primarily chironomids, tiny crustaceans, and small insect larvae

History:

Uses:

Reproduction:

  • Spawning males establish territories around partially embedded rocks in the spring when the water temperature approaches 60º F. A nest site is prepared by turning upside down and rubbing the area with the caudal, anal and pelvic fins, while balancing with the aid of the pectorals. Gravid females are approached with fins lowered and are led beneath the rock where nest polishing is resumed. The female may then join the male, head to head, and deposit 30 to 200 eggs in the nest. Females may lay 5 or 6 egg clutches, and males sometimes accumlate a thousand or more eggs from several females. Males then guard the eggs until hatched.

Comments:

  • Brown color and dark markings make for effective camouflage. Often goes unseen until it darts away.

Links:

Boreal border

Last updated on 15 October 1999