Mottled Sculpin - Cottus bairdi
Mottled Sculpin, Color Plate - Cottus bairdi
Global Rank:
G5
State Rank:
S5
Agency Status
USFWS:
none
USFS:
none
BLM:
none
CFWCS Tier:
3


General Description
The mottled sculpin is well-named from the way it blends in with the rocks. The mottled sculpin is a native fish, widespread in Montana in mountain streams east of the Continental Divide. Like all sculpins, the mottled species eats primarily aquatic insects. They occasionally eat small fish or trout eggs but this is not a large part of their diet.
Diagnostic Characteristics
The back and sides are slate to brown with mottling and dark blotches. They may have two or three dark saddles under the second dorsal fin. The underside is whitish. The first dorsal fin is fringed with orange or red on breeding males. Palatine teeth are present.
Distribution
Montana Range
Habitat
They prefer riffle areas of fast-flowing streams that are clear and have rocky bottoms.
Food Habits
Food includes a variety of immature aquatic organisms, but midge and acddis larvae are by far the most important. A study in southwest Montana showed bottom-dwelling aquatic insects comprising 99.7% of the diet.
Ecology
The species serves as a forage fish for predators, often trout.
Reproductive Characteristics
They are sexually mature in 2 years. Spawning occurs in May-June. The eggs hatch in 20-30 days at 50-60 degrees F. A southwest Montana study showed spawning throughout the month of June.
Citations & Sources
- Holton, G. D. 2003. A field guide to Montana fishes. Mont. Dept. Fish, Wildl. Parks, 95 pp.