Photo 184507, (c) garyg, some rights reserved (CC BY-NC-SA), uploaded by Gary Griffith

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Attribution © Gary Griffith
Cc-by-nc-sa_small some rights reserved
Associated observations

Photos / Sounds

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What

signal crayfish Pacifastacus leniusculus

Observer

garyg

Date

October 6, 2012

Description

single crayfish moving slowly across the silty bottom of a pool in South Fork Wolf Creek; it eventually excavated a space under an underwater root by the creek bank and disappeared; note the white 'signal flag' patch on the claw; native to the Pacific Northwest, this is an invasive species in California & the Sierra Nevada; it has outcompeted native crayfish and reduced benthic populations, particularly snails; once in a stream it is very difficult to eradicate.

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