[3] The prickly sculpin camouflages with muted tones it is brown, gray, or olive green on its upper parts and white or yellowish ventrally.

[5] The diet of the fish includes water invertebrates, insects and their larvae,[5] salmon eggs,[2] fish larvae, especially those of the Sacramento sucker (Catostomus occidentalis occidentalis), and zooplankton, especially Daphnia spp.

[9] The prickly sculpin lives and hunts at the bottom of tide pools and streams.

In its habitat it lives alongside its relative, the coastrange sculpin (Cottus aleuticus), which is quite similar to it in terms of morphology and behavior.

[10][11] It can also be found with the three-spined stickleback (Gasterosteus aculeatus), steelhead trout (Oncorhynchus mykiss),[9] Klamath small-scale sucker (Catostomus rimiculus), coastal cutthroat trout (Oncorhynchus clarki clarki), Chinook salmon (O. tshawytscha), and coho salmon (O.

[11] Sculpins avoid predators by hiding along the bottom of the streams under rocks and wood.

The male creates a nest under debris such as logs or garbage, and the female lays many eggs, from a few hundred up to 11,000.

[5] This fish is common in most of its range, becoming quite abundant in the summer when recruitment occurs and the previous season's juveniles join the population.