Skip to main content
U.S. flag

An official website of the United States government

Comparative ecology of prickly sculpin, Cottus asper, and coastrange sculpin, C. aleuticus, in the Eel River, California

January 1, 1995

We documented species' distributions, size structure of populations, abundance in mainstem and tributary streams, habitat use, and diets of prickly sculpin, Cottus asper, and coastrange sculpin, C. aleuticus, in the Eel River drainage of California, to determine the processes allowing coexistence of these very similar fishes. We observed prickly sculpins at 43 sites and coastrange sculpins at 34. The species co-occurred at 26 sites. Young-of-year coastrange sculpins were only observed within 42 km of the ocean, but young-of-year prickly sculpins were present throughout the species range. Mean, maximum, and minimum lengths of coastrange sculpins were positively correlated with distance from the ocean but no significant relationships were found for prickly sculpins. Absolute abundance of both species was highest in mainstem habitat (prickly sculpins = 0.6 sculpins m−2 and coastrange sculpins = 0.4 sculpins m−2) . Tributary densities of both species tended to be less than 0.1 sculpins m−2. The species inhabited very similar habitats and had very similar diets. Coastrange sculpin populations in upstream areas were maintained by immigration from downstream areas in contrast with prickly sculpin populations that produced young-of-year fish throughout their range. Densities were probably not high enough for interspecific interactions to be important. The factors limiting the upstream distribution of the species may include high water temperatures, stability of the stream bed, and behavior of the fish. In the past, the range of sculpins within the Eel River drainage probably fluctuated with changing physical conditions. Recent introductions of exotic species that compete with and prey upon sculpins, and ongoing human activities in the drainage could result in major reductions in the distribution and abundance of one or both species.

Publication Year 1995
Title Comparative ecology of prickly sculpin, Cottus asper, and coastrange sculpin, C. aleuticus, in the Eel River, California
DOI 10.1007/BF00001462
Authors Larry R. Brown, Scott A. Matern, Peter B. Moyle
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Biology of Fishes
Index ID 70199487
Record Source USGS Publications Warehouse
USGS Organization California Water Science Center