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Mottled sculpin

Mottled sculpin


The head and anterior body is flattened dorso-ventrally with the posterior body and caudal peduncle compressed laterally. The mouth is terminal and has numerous teeth in narrow bands on both jaws. It has two dorsal fins that are narrowly connected; the first has 6 to 9 soft spines and the second has 17 to 19 rays. The anal fin has 13 to 15 rays, the pelvic fin is thoracic with one spine and 4 rays, and the pectoral fin has 14 to 15 rays. Scales are absent along the incomplete lateral line ending under the second dorsal fin. The back and sides are brown to tan with dark mottling, and the lower region of the head and belly are whitish. This fish averages 3- to 4-inches long.


Mottled sculpin Distribution

Northeast Iowa trout streams


Larval aquatic insects, invertebrates

State Record

Expert Tip

Trout fishermen sometimes use Mottled Sculpins for bait when they are fishing for large Brown Trout.


The Mottled Sculpin lives in northeast Iowa trout streams. It is somewhat less common than the Slimy Sculpin and is found in warmer waters. Mottled Sculpin are found in streams with an average water temperature of 68 degrees (range 61 to 72 degrees).

The Mottled Sculpins` behavior and feeding habits are similar to the Slimy Sculpin. It can modify its body colors to match the background which helps it escape predation and may be useful in ambushing food items.

The Mottled Sculpin has often been called a "trout indicator" and usually where there are sculpin populations, the water usually holds trout as well. 

Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.


Present in these Iowa water bodies: