Freshwater Drum

Key Characteristics:

  • Higher pre-anal count than post-anal.
  • Huge mouth.
  • Big head.
  • Distinct – only one fish in this family in Lake Michigan. 
  • Preanal myomeres: 10-14
  • Postanal myomeres: 9-11
  • Shorter gut
  • Posterior oil globule in yolk-sac larvae
Larval Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer.

Larval Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer. 2017.

Larval Freshwater Drums. 8 mm. United States Fish Wildlife Service. Green bay Harbor, WI. Marian Shaffer.

Larval Freshwater Drums. 8 mm. United States Fish Wildlife Service. Green Bay Harbor, WI. Marian Shaffer. 2017.

Larval Freshwater Drums. 10 mm. United States Fish Wildlife Service. Green Bay Harbor, WI. Ashley Smith.

Larval Freshwater Drums. 10 mm. United States Fish Wildlife Service. Green Bay Harbor, WI. Ashley Smith. 2018.

Larval Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer.

Larval Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer. 2017.

Larval Freshwater Drum. 17 mm. United States Fish Wildlife Service. Green Bay Harbor, WI. Adam Dziewa.

Larval Freshwater Drum. 17 mm. United States Fish Wildlife Service. Green Bay Harbor, WI. Adam Dziewa. 2018.

Different Larval Stages of Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer.

Different Larval Stages of Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer. 2017.

Different Larval Stages of Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer.

Different Larval Stages of Freshwater Drum. United States Fish Wildlife Service. Marian Shaffer. 2017.

Dr. Auer’s Dichotomous Key

  • Body not elongated, eel-shaped, round in transverse section, uniformly pigmented (1B)
  • Chin barbels absent (3B)
  • Snout short, its length usually less than 10% TL; median fins otherwise (5B)
  • Median fins or finfolds showing distinct separation (7B)
  • No adipose fin, or demarcation of one, in finfold (10B)
  • Preanal myomeres greater than or equal to postanal myomeres (14A)
  • Preanal myomeres approximately equal to postanal myomeres (difference five myomeres or less) (15A)
  • Total myomeres less than 35 (20B)
  • Total myomeres less than 26 (21A)
  • Preanal myomeres greater than postanal myomeres; head large and blunt; mouth very large; maxilla extending to or beyond posterior of the eye; caudal fin lancealate at 12 mm TL (22A)
    • Sciaenidae

Adult History 

  • Physical Description
    • Rounded or triangular tail, steep head, downturned mouth, humped back, dorsal fin extends from hump near the tail, lateral line running from head to through the tail, small teeth on the jaws, body coloration: silver, white, and green mixture, 48-53 ctenoid lateral scales, dorsal fin with two distinct lobes, and its pelvic fin with the first ray elongated into a filament
  • Spawning Habitat
    • Open water or near the surface
    • Within the water column
  • Spawning Substrate
    • Eggs are deposited in either gravel or sand
    • Eggs are fertilized and left floating near the surface
      • Carried by the currents
  • Spawning Behavior
    • Polygynandry Behavior
    • Breed once a year
    • No parental involvement after the eggs hatch
      • When they obtain more muscle strength – swim into deeper water
  • Time of Year
    • April – June in Lake Michigan
    • Spawning typically takes place at water temperatures of 65 – 80°F
  • Diet
    • Piscivore/insectivore/omnivore – snails, zebra mussels, eggs, aquatic insects, aquatic crustaceans, zooplankton, and small fish
Sea Grant

Adult Freshwater Drum. UW – Sea Grant, UW – Madison, and NOAA. John Lyons.

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