Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Scorpaeniformes
(Scorpionfishes and flatheads) > Cottidae
Etymology: Cottus: Greek, kottos = a fish (Ref. 45335); rhotheus: rhotheus -- rushing of the torrent, referring to habitat (Ref. 1998).
Environment / Climate / Range
Freshwater; demersal. Temperate; 52°N - 42°N
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 15.5 cm TL male/unsexed; (Ref. 1998); common length : 6.8 cm TL male/unsexed; (Ref. 12193)
Morphology | Morphometrics
North America: upper Fraser River drainage in British Columbia in Canada to Nehalem River in Oregon, USA (including Columbia River drainage of British Columbia in Canada, and Washington, Idaho, Montana and Oregon in the USA).
Inhabits rubble and gravel riffles of rivers and rocky lake shores. Individuals up to 5 cm feed on planktonic crustaceans and aquatic insect larvae especially that of midges and mayflies (Ref. 1998). Larger sculpins feed on minnows and other fishes (Ref. 1998). Possibly spawns in June (Ref. 1998).
Page, L.M. and B.M. Burr, 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p. (Ref. 5723)
IUCN Red List Status (Ref. 90363)
CITES (Ref. 94142)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
CollaboratorsPicturesStamps, CoinsSoundsCiguateraSpeedSwim. typeGill areaOtolithsBrainsVision
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01122 (0.00363 - 0.03467), b=3.11 (2.86 - 3.36), based on LWR estimates for this Subfamily-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.4 ±0.45 se; Based on food items.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Fec=448).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (33 of 100) .