Home/Species/ Signal Crayfish

Pacifastacus leniusculus

(Dana, 1852)

Signal Crayfish

G5Secure Found in 148 roadless areas NatureServe Explorer →

G5SecureGlobal Rank

Least concernIUCN

LowThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.113778

Element CodeICMAL31040

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryInvertebrate Animal

IUCNLeast concern

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomAnimalia

PhylumArthropoda

ClassMalacostraca

OrderDecapoda

FamilyAstacidae

GenusPacifastacus

Other Common Names

écrevisse du Pacifique (FR) Noble Crayfish (EN)

Concept Reference

Hobbs, H. H., Jr. 1989. An Illustrated Checklist of the American Crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Contributions to Zoology 480:1-236.

Taxonomic Comments

Three subspecies have been recognized, P. l. leniusculus, P. l. klamathensis, and P. l. trowbridgii, but more work is needed to clarify their status (see Sonntag 2006, Larson et al. 2012, Larson et al. 2016). No subspecies were recognized in Crandall and De Grave (2017). Kawai (2018) provides a detailed description of the taxa with illustrations of taxonomic characteristics for further taxonomic works.

Conservation Status

Rank MethodExpertise without calculation

Review Date2016-02-22

Change Date1996-02-19

Edition Date2009-07-01

Edition AuthorsCordeiro, J.

Threat ImpactLow

Range Extent>2,500,000 square km (greater than 1,000,000 square miles)

Number of Occurrences> 300

Rank Reasons

This is an invasive, r-selected and widespread species which is able to out-compete native species often growing to a larger size. This species is also resistant to the crayfish plague but is a carrier the disease and is able to thrive in a wide reange of habitats. It has been introduced into Europe and outside of its native range in the USA. No conservation measures are required.

Range Extent Comments

Ranges from British Columbia to California; introduced into Europe and Japan (Hobbs, 1989). Pacifastacus leniculus has been introduced into many countries throughout Europe and California, Nevada and Utah in the USA. This species was introduced during the 1970s and 1980s, is widely cultivated and is established in the wild, from where it is harvested (Harlioglu and Holdich, 2001). Pacifastacus leniusculus leniusculus is distributed throughout British Columbia, California, Idaho, Oregon, and Washington. Pacifastacus leniusculus klamathensis is distributed throughout British Columbia in Canada, Idaho and south to central California in the USA. Pacifastacus leniusculus trowbridgii is distributed throughout British Columbia in Canada and California, Idaho, Oregon and Washington in the USA, and has been introduced into California and Nevada in the USA, and also introduced into Japan.

Occurrences Comments

Extremely common species. Harvested population in Lake Billy Chinook, Oregon, found to have mean density of 0.24 to 1.13 per square meter with total abundance 36 million (+- 8 million) individuals (Lewis and Horton, 1996). Introductions have been made throughout California, Nevada and Utah, as well as various parts of Europe (Rogers, 2005).

Threat Impact Comments

There are no known threats.

Ecology & Habitat

Habitat

Generally prefers cool water with current over rocky bottom; does not burrow; is highly adaptable and can be found in a wide variety of habitats including coastal and mountain streams and lakes, reservoirs, and the saline waters in river deltas (Hogger, 1988).

Reproduction

Lewis and Horton (1996) found for populations in Oregon that hatching began during the second week in April and eight age classes identified.

Other Nations (2)

CanadaN5

Province	Rank	Native
British Columbia	S5	Yes

United StatesN5

Province	Rank	Native
Wyoming	SNR	Yes
Oregon	SNR	Yes
Nevada	SNA	No
California	SNR	Yes
Montana	S5	Yes
Utah	SNA	Yes
Washington	SNR	Yes
Idaho	S4	Yes

Roadless Areas (148)

California (59)

Area	Forest	Acres
Bear Mountain	Los Padres National Forest	913
Bell Quinby	Shasta-Trinity National Forest	11,556
Black	Klamath National Forest	6,530
Black Butte	Los Padres National Forest	5,116
Bonanza King	Shasta-Trinity National Forest	16,402
Bucks Lake	Plumas National Forest	680
Caples Creek	Eldorado National Forest	17,854
Carson - Iceberg	Stanislaus National Forest	56,430
Castle Crags A	Shasta-Trinity National Forest	113
Castle Crags B	Shasta-Trinity National Forest	1,619
Castle Peak	Tahoe National Forest	14,974
Channell	Sequoia National Forest	45,429
Chico	Sequoia National Forest	39,836
Chinquapin	Shasta-Trinity National Forest	22,040
Chips Creek	Plumas National Forest	12,940
Chips Creek	Lassen National Forest	29,089
Cow Creek	Shasta-Trinity National Forest	22,627
Duncan Canyon	Tahoe National Forest	8,621
East Yuba	Tahoe National Forest	17,968
Ebbetts	Humboldt-Toiyabe National Forest	255
Glass Mountain	Inyo National Forest	52,867
Granite Chief	Tahoe National Forest	6,546
Grizzly Peak	Plumas National Forest	6,222
Grouse Lakes	Tahoe National Forest	19,085
Hoover - North	Humboldt-Toiyabe National Forest	1,574
Kangaroo	Klamath National Forest	40,617
Kings River	Sierra National Forest	52,999
Lake Eleanor	Shasta-Trinity National Forest	397
Little French C	Shasta-Trinity National Forest	11,529
Middle Fork	Plumas National Forest	29,278
Middle Yuba	Tahoe National Forest	7,379
Mill Creek	Sequoia National Forest	27,643
Mt. Jackson	Humboldt-Toiyabe National Forest	20,721
Mystic (CA)	Humboldt-Toiyabe National Forest	836
North Fork American River	Tahoe National Forest	38,495
North Fork Smith	Six Rivers National Forest	37,898
Oat Mtn.	Sequoia National Forest	12,223
Orleans Mtn.	Klamath National Forest	49,090
Orleans Mtn. C	Six Rivers National Forest	15,589
Packsaddle	Six Rivers National Forest	3,862
Pattison	Shasta-Trinity National Forest	29,299
Poison Hole	Eldorado National Forest	2,627
Portuguese	Klamath National Forest	18,915
Pyramid	Eldorado National Forest	24,347
Raymond Peak	Stanislaus National Forest	3,646
Rincon	Sequoia National Forest	54,610
Robinson Peak	Humboldt-Toiyabe National Forest	5,835
Russian	Klamath National Forest	21,771
San Joaquin	Sierra National Forest	22,474
Siskiyou	Klamath National Forest	54,039
Siskiyou B	Six Rivers National Forest	18,871
Snoozer	Klamath National Forest	23,414
South Fork	Shasta-Trinity National Forest	16,786
Timbered Crater	Lassen National Forest	4,096
Tragedy - Elephants Back	Eldorado National Forest	20,866
Trail Lake	Lassen National Forest	1,124
Waterhouse	Stanislaus National Forest	4,394
Watterson	Inyo National Forest	6,922
West Girard	Shasta-Trinity National Forest	37,516

Idaho (4)

Area	Forest	Acres
Bighorn - Weitas	Nez Perce-Clearwater National Forest	254,845
Lemhi Range	Salmon-Challis National Forest	308,533
Peace Rock	Boise National Forest	191,734
West Meadow Creek	Nez Perce-Clearwater National Forest	115,949

Montana (13)

Area	Forest	Acres
Allan Mountain (01946)	Bitterroot National Forest	104,184
Bear - Marshall - Scapegoat - Swan	Lolo National Forest	118,485
Bridger	Gallatin National Forest	45,059
Buckhorn Ridge (MT)	Kootenai National Forest	34,716
Cube Iron - Silcox	Lolo National Forest	36,998
Hoodoo	Lolo National Forest	105,162
Patricks Knob - North Cutoff	Lolo National Forest	16,970
Quigg	Lolo National Forest	67,267
Reservation Divide	Lolo National Forest	16,908
Selway - Bitterroot (01067)	Bitterroot National Forest	114,953
Silver King	Beaverhead-Deerlodge National Forest	64,289
South Siegel - South Cutoff	Lolo National Forest	13,474
Stony Mountain	Lolo National Forest	32,796

Nevada (7)

Area	Forest	Acres
Boundary Peak (NV)	Inyo National Forest	21,851
Bunker Hill	Humboldt-Toiyabe National Forest	27,569
Mystic (NV)	Humboldt-Toiyabe National Forest	5,644
Pine Grove North	Humboldt-Toiyabe National Forest	8,749
Pine Grove South	Humboldt-Toiyabe National Forest	88,945
Steward Basin	Humboldt-Toiyabe National Forest	4,475
Toiyabe Range	Humboldt-Toiyabe National Forest	99,225

Oregon (46)

Area	Forest	Acres
Badger Creek	Mt. Hood National Forest	847
Bull Of The Woods	Mt. Hood National Forest	8,843
Castle Rock Appendage	Umpqua National Forest	4,649
Cougar Bluff	Umpqua National Forest	5,574
Drift Creek	Siuslaw National Forest	6,333
Eagle	Mt. Hood National Forest	16,841
Elkhorn	Willamette National Forest	9,380
Fairview	Umpqua National Forest	7,417
French Pete (a)	Willamette National Forest	1,668
Gordon Meadows	Willamette National Forest	9,463
Greenhorn Mountain	Malheur National Forest	15,936
Greenhorn Mtn.	Umatilla National Forest	11,191
Hebo 1a	Siuslaw National Forest	13,930
Jaussaud Corral	Umatilla National Forest	5,535
Lake	Mt. Hood National Forest	1,327
Larch	Mt. Hood National Forest	12,961
Last	Umpqua National Forest	7,666
Lord Flat Somers Point	Wallowa-Whitman National Forest	67,738
Maiden Peak	Willamette National Forest	9,627
Maiden Peak	Deschutes National Forest	26,432
Mclennon Mountain	Willamette National Forest	8,085
Menagerie (rooster Rock)	Willamette National Forest	374
Middle Santiam	Willamette National Forest	7,316
Moose Lake	Willamette National Forest	5,013
Mt. Jefferson	Deschutes National Forest	2,282
Mt. Bailey	Umpqua National Forest	18,401
Mt. Hood Additions	Mt. Hood National Forest	13,061
North Kalmiopsis	Siskiyou National Forests	91,560
North Paulina	Deschutes National Forest	19,670
Opal Creek	Willamette National Forest	5,417
Roaring River	Mt. Hood National Forest	27,316
Salmon - Huckleberry	Mt. Hood National Forest	17,570
Skimmerhorn Appendage	Umpqua National Forest	1,820
Sky Lakes A	Winema National Forest	3,940
Snake River	Wallowa-Whitman National Forest	31,229
South Kalmiopsis	Siskiyou National Forests	104,477
South Paulina	Deschutes National Forest	9,074
Tahkenitch	Siuslaw National Forest	5,799
Tenmile	Siuslaw National Forest	10,818
Twin Lakes	Mt. Hood National Forest	6,055
Upper Grande Ronde	Wallowa-Whitman National Forest	11,723
Waldo	Deschutes National Forest	4,973
Walla Walla River	Umatilla National Forest	34,416
West - South Bachelor	Deschutes National Forest	25,994
Williams Creek	Umpqua National Forest	5,844
Wind Creek	Mt. Hood National Forest	5,438

Washington (19)

Area	Forest	Acres
Backbone	Gifford Pinchot National Forest	1,201
Bear Creek	Gifford Pinchot National Forest	7,980
Big Lava Bed	Gifford Pinchot National Forest	19,043
Dark Divide	Gifford Pinchot National Forest	52,483
Entiat	Wenatchee National Forest	72,617
Granite Mountain	Okanogan National Forest	27,428
Horseshoe	Gifford Pinchot National Forest	7,579
Jefferson Ridge	Olympic National Forest	6,512
Jupiter Ridge	Olympic National Forest	10,148
Lightning	Olympic National Forest	7,179
Long Swamp	Okanogan National Forest	66,344
Mt. Baldy	Olympic National Forest	3,557
Packwood Lake	Gifford Pinchot National Forest	1,084
Quartz	Wenatchee National Forest	8,550
Silver Star	Gifford Pinchot National Forest	7,779
South Quinault	Olympic National Forest	11,081
Taneum	Wenatchee National Forest	26,140
Teanaway	Wenatchee National Forest	72,849
Thorp Mtn.	Wenatchee National Forest	22,717

References (16)

Bubb, D.H., T.J. Thom, and M.C. Lucas. 2004. Movement and dispersal of the invasive signal crayfish Pacifastacus leniusculus in upland rivers. Freshwater Biology, 49: 357-368.
Crandall, K. A., and S. De Grave. 2017. An updated classification of the freshwater crayfishes (Decapoda: Astacidea) of the world, with a complete species list. Journal of Crustacean Biology 37(5):615-653.
Goldman, C.R. and J.C. Rundquist. 1977. A comparative ecological study of the Californian crayfish P. leniusculus (Dana) from two subalpine lakes. Freshwater Crayfish, 3: 51-80.
Guan, R.Z. and P.R. Wiles. 1998. Feeding ecology of the signal crayfish Pacifastacus leniusculus in a British lowland river. Aquaculture 169(3-4): 177-193.
Harlioglu, M. M. and D. M. Holdich. 2001. Meat yields in the introduced crayfish, Pacífastacus leniusculus and Astacus leptodactylus, from British waters. Aquacultural Research 32:411-417.
Hobbs, H. H., Jr. 1989. An Illustrated Checklist of the American Crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Contributions to Zoology 480:1-236.
Hogger, J.B. 1988. Ecology, population biology and behaviour. Chapter 5, pages 114-144 In D.M. Holdich and R.S. Lowery (eds.) Freshwater Crayfish. Biology, Management and Exploitation. Croom Helm: London, and Timber Press: Portland, Oregon. 498 pp.
Kawai, T. 2018. Observation of museum specimens of the genus Pacifastacus Bo , 1950 (Decapoda: Astacidae). Nauplius 26: e2018001
Larson, E. R., C. L. Abbott, N. Usio, N. Azuma, K. A. Wood, L-M. Herborg, and J. D. Olden. 2012. The signal crayfish is not a single species: cryptic diversity and invasions in the Pacific Northwest range of Pacifastacus leniusculus. Freshwater Biology 57(9):1823-1838.
Larson, E. R., M. Castelin, B. W. Williams, J. D. Olden, and C. L. Abbott. 2016. Phylogenetic species delimitation for crayfishes of the genus Pacifastacus.PeerJ 4 (2016): e1915.
Lewis, S.D. and H.F. Horton. 1996. Life history and population dynamics of the signal crayfish, Pacifastacus leniusculus, in Lake Billy Chinook, Oregon. Freshwater Crayfish 11: 34-53.
Light, T. 2005. Behavioral effects of invaders: alien crayfish and native sculpin in a California stream. Biological Invasions 7: 353-367.
McLaughlin, P. A., D. K. Camp, M. V. Angel, E. L. Bousfield, P. Brunel, R. C. Brusca, D. Cadien, A. C. Cohen, K. Conlan, L. G. Eldredge, D. L. Felder, J. W. Goy, T. Haney, B. Hann, R. W. Heard, E. A. Hendrycks, H. H. Hobbs III, J. R. Holsinger, B. Kensley, D. R. Laubitz, S. E. LeCroy, R. Lemaitre, R. F. Maddocks, J. W. Martin, P. Mikkelsen, E. Nelson, W. A. Newman, R. M. Overstreet, W. J. Poly, W. W. Price, J. W. Reid, A. Robertson, D. C. Rogers, A. Ross, M. Schotte, F. Schram, C. Shih, L. Watling, G. D. F. Wilson, and D. D. Turgeon. 2005. Common and Scientific Names of Aquatic Invertebrates from the United States and Canada: Crustaceans. American Fisheries Society Special Publication 31. 545 pp.
Rogers, D.C. 2005. Identification manual to the freshwater Crustacea of the western United States and adjacent areas encountered during bioassessment. EcoAnalysts, Inc., Technical Publication #1, Moscow, Idaho. 81 pp.
Sonntag, M.M. 2006. Taxonomic standing of the three subspecies of Pacifastacus leniusculus, and their phylogeographic patterns in the Klamath basin area. Bringham Young University, Provo, UT, Master Thesis.
Taylor, C. A., G. A. Schuster, J. E. Cooper, R. J. DiStefano, A. G. Eversole, P. Hamr, H. H. Hobbs III, H. W. Robison, C. E. Skelton, and R. F. Thoma. 2007. A reassessment of the conservation status of crayfishes of the United States and Canada after 10+ years of increased awareness. Fisheries 32(8):371-389.