A. Astacidae Pacifastacus leniusculus

Signal Crawdad

Lenient Pacific-crawfish Lobster Lobster-like

Astacoidea is superfamily of freshwater crayfish that live in the Northern Hemisphere. The other superfamily of crayfish, Parastacoidea, lives in the Southern Hemisphere. Astacoidea consists of three families: Astacidae (from Europe and western North America), Cambaridae (from eastern North America), and Cambaroididae (from eastern Asia). Crayfish are closely related to lobsters, as shown in the simplified cladogram below:

Astacoidea. Retrieved May, 22 2023, from

Astacidae is a family of freshwater crayfish native to Europe and western North America. The family is made up of four extant (living) genera: The genera Astacus (which includes the European crayfish), Pontastacus (which includes the Turkish crayfish), and Austropotamobius are all found throughout Europe and parts of western Asia, while Pacifastacus is found on the Pacific coast of the United States and British Columbia and includes the signal crayfish and the Shasta crayfish.

Astacidae. Retrieved May, 22 2023, from

The signal crayfish (Pacifastacus leniusculus) is a North American species of crayfish. It was introduced to Europe in the 1960s to supplement the North European Astacus astacus fisheries, which were being damaged by crayfish plague, but the imports turned out to be a carrier of that disease. The signal crayfish is now considered an invasive species across Europe, Japan, and California, ousting native species there.

Pacifastacus leniusculus. Retrieved May, 22 2023, from