University of California
California Fish Website

Fish Species


 Common Name Rough Sculpin
 Scientific Name Cottus asperrimus
 Native Yes
 Identification
  • Small and slim, maximum 81 mm SL
  • Body covered with prickles, giving “rough” feel
  • Light to purplish brown, dusky sides with 4-5 blotches, speckled underside
  • Dorsal fin brown to red with streaks
  • Fin spines/rays: pelvic 1 spine/3 rays, 1st dorsal 5-7 spines, 2nd dorsal 17-19 rays, anal 13-17 rays, pectoral 14-16 rays
  • Pelvic fin "elements": 3 (1 spine, 3 rays, but the spine is fused with the 1st ray)
  • Lateral line (incomplete): doesn’t extend past posterior margin of 2nd dorsal, 19-29 pores
 Life History Rough Sculpins are primarily found in clear, cool, fast water. They live in spring-fed streams where water temperatures rarely exceed 15°C and occupy areas with aquatic vegetation and a sand or gravel substrate. While Rough Sculpins have shown a preference for cool water, they are capable of surviving in lakes or reservoirs where surface water temperatures reach 30°C. They are commonly found in association with Marbled Sculpins, Rainbow Trout, Sacramento Suckers, Tui Chubs, and Pit-Klamath Brook Lampreys. Feeding occurs during both day and night, with peaks at dawn and dusk. Prey such as amphipods and isopods are captured at night, and are generally larger and more active than daytime prey. Throughout the year Rough Sculpins feed on chironomid and baetid mayfly larvae, though they tend to avoid snails and stonefly larvae. The diversity in a sculpins diet increases with body size. Rough Sculpins grow slower than other sculpin species. Both sexes grow at a similar rate, though male sculpins reach larger maximum sizes. They reach sexual maturity in around 2 years and when they are bigger than 35 mm SL. The time of spawning varies between streams, with some populations spawning in fall to winter, and others spawning in winter through spring. Males find a secure nest site in various kind of habitat, where they try to entice females to spawn. Egg production is size dependent, with most females producing 140-580 large eggs. One male might have 800 to 3,000 eggs in a nest which he guards for several weeks till the larvae hatch. The newly emerged larvae remain close to the nest while developing.

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