Signal crayfish

Pacifastacus leniusculus
#nm_0619📍 International
Language
English
Transliteration
Signal crayfish

Compound: signal + crayfish signal: the pale patch at the hinge of the claw, likened to the white flags signalmen used to direct trains, crayfish: freshwater crustacean ↳ crayfish from Old French crevice (crayfish) ↳ From Frankish *krebit (crayfish), related to German Krebs (crab)

Freshwater crayfish typically 6-9 cm long, reaching 16-20 cm. Smooth carapace, brown to reddish above, with a distinctive white to pale blue-green patch at the hinge of each claw. Native to the Columbia River basin of western North America. Introduced to Europe from 1960 and established in 27 countries by 2009. A largely resistant carrier of crayfish plague (Aphanomyces astaci), which is fatal to European crayfish.