Common name: Bear Lake Sculpin
available through www.itis.gov
Identification: Page and Burr (1991); Sigler and Sigler (1996).
Size: 17 cm TL
Native Range: Bear Lake, Utah and Idaho (Page and Burr 1991).
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Cottus extensus are found here.
Table last updated 2/25/2021
† Populations may not be currently present.
Ecology: Bear Lake Sculpin are small (generally less than 90 mm TL) cottids endemic to Bear Lake, and are one of the most abundant fishes in the lake. They occur throughout the lake, with adults spawing in littoral areas on rocky substrate, and juveniles found throughout the lake in benthic habitats (to 50 m depth) (Sigler and Sigler 1996; Ruzycki et al. 1998). The are benthic carnivores, primarily consuming zooplankton and benthic invertebrates. Juveniles occuring in the deeper profundal portion of the lake perform diel vertical migrations to warmer, shallower waters at night, an adaptation to speed digestion (Wurtsbaugh and Neverman 1988).
Means of Introduction: Intentionally stocked into Flaming Gorge Reservoir (Sigler and Sigler 1987, 1996), apparently to serve as forage for large predatory fish species.
Status: Established in Flaming Gorge Reservoir (Utah Division of Wildlife Resources 2012).
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Page, L.M., and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA.
Ruzycki, J.R., W.A. Wurtsbaugh, and C. Lay. 1998. Reproductive ecology and early life history of a lacustrine sculpin, Cottus extensus (Teleostei, Cottidae). Environmental Biology of Fishes 53:117-127.
Sigler, W.F., and J.W. Sigler. 1987. Fishes of the Great Basin: A Natural History. University of Nevada Press, Reno, NV.
Sigler, W.F., and J.W. Sigler. 1996. Fishes of Utah. University of Utah Press, Salt Lake City, UT.
Utah Division of Wildlife Resources. 2012. Bear Lake sculpin. http://dwrcdc.nr.utah.gov/rsgis2/search/Display.asp?FlNm=cottexte. Accessed on 24 Jan 2012
Wurtsbaugh, W.A. and D. Neverman. 1988. Post-feeding thermotaxis and daily vertical migration in a larval fish. Nature 333:846-848.
Pam Fuller, and Matt Neilson
Revision Date: 1/24/2012
Peer Review Date: 1/24/2012
Pam Fuller, and Matt Neilson, 2021, Cottus extensus Bailey and Bond, 1963: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=503, Revision Date: 1/24/2012, Peer Review Date: 1/24/2012, Access Date: 2/25/2021
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.