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Most common European crayfish (also called noble crayfish). Native to fresh waters from France through Central Europe to the Balkans, with northern populations in Scandinavia, Finland, and Eastern Europe. Restricted to unpolluted streams, rivers, and lakes; prefers sandy substrates. Keystone species in its ecosystems. Listed as vulnerable (IUCN) — populations reduced to ~5% by crayfish plague carried by invasive North American signal crayfish.