Mottled Sculpin

Key Characteristics:

  • 36-43 total myomeres
  • Body elongated
  • Melanophores may appear along dorsum of (inside lining of fish) peritoneum
Caption

Larval Mottled Sculpin. 5 mm. United States Fish & Wildlife Service. Green Bay, WI. 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 significantly less than postanal myomeres (difference greater than five myomeres) (14B)
  • Postanal myomeres less than 35, total myomeres less than 50, chin barbel absent (16B)
  • Postanal myomeres less than 25, preanal length usually greater than 40% TL (17B)
  • Mouth Terminal or inferior; usually two dorsal fins (18B)
  • Pectoral fins well developed; head depressed; swim bladder not visible (19A)
    • Cottidae

Or*

  • 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 continuous, or nearly so (7A)
  • Pectoral fins large and usually well developed; lower jaw without barbel; urostyle upturned or notochord straight, if straight caudal fin rays developed on ventral half only (8B)
  • Larva sparsely pigmented; often exhibiting “saddle markings” on dorsum; opercle often with spine(s); notochord flexed; mouth subterminal (9B)
    • Cottidae

Adult History 

  • Physical Description
    • Lacks scales, terminal and wide mouth, separate thoracic pelvic fins (1 spine and 4 rays each) (wing-like), eyes on top of broad head, spotted brown/black coloration, two dorsal fins (first: 6-9 spines/second: 17-19 rays), small black spot on the first dorsal fin while also having a larger black spot on the back of the first dorsal fin, and rounded snouts
  • Spawning Habitat
    • Streams and shoreline areas of lakes
    • Between a depth of 15 – 35 centimeters
  • Spawning Substrate
    • Eggs are deposited on aquatic vegetation, soil cavities, an underside of objects, or gravel bottoms
  • Spawning Behavior
    • Polygynandry Behavior
    • Males migrate to the shoreline
    • Spawning Physical Characteristics
      • Males have a darker band on the first dorsal fin
      • Orange band on the edge of the fin
    • Courtship Behavior
      • Raise their gills, shake their heads, and undulate their bodies
      • Males bite females on the tail, fins, cheeks, or sides and drag her into the nest
      • Female releases her eggs by turning upside down
      • Males’ head and fins will turn black and his body pale while protecting his nest
        • Allow other females to spawn in his cavity
      • Males defend their nests or cavities until their young become independent
    • Time of Year
      • March/April – May in Lake Michigan
      • Spawning typically takes place at water temperatures of 40 – 65°F
    • Diet
      • Leaves, algae, small fish, eggs, aquatic insect larvae, and aquatic crustaceans
Sea Grant

Adult Mottled Sculpin. UW – Sea Grant, UW – Madison, and NOAA. John Lyons. 2013.

Adult Mottled Sculpin. UW – Sea Grant, UW – Madison, and NOAA. John Lyons.

Adult Mottled Sculpin. UW – Sea Grant, UW – Madison, and NOAA. John Lyons. 2013.

Reference Page