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Invasive Species: Crustaceans

Invasive Crustaceans

Species that are not native and also have the potential to harm human health or to harm natural, agricultural or silvicultural resources can be listed as prohibited or restricted by the State of Michigan. If a species is prohibited or restricted, it is unlawful to possess, introduce, import, sell or offer that species for sale as a live organism, except under certain circumstances.

Killer Shrimp

(Dikerogammarus villosus)

Prohibited in Michigan

Killer shrimp have body coloration ranges from transparent and striped to a uniform dark color. They have a curled body that that is laterally compressed. The first four pairs of legs extend down and backwards and they have two pairs of antennae. Their habitat consists of fresh/brackish water in lakes, rivers, and canals.

More information: Killer shrimp

Marbled Crayfish

(Procambarus virginalis)

Watch List - Prohibited in Michigan

A medium-sized (4 to 5 inch) crayfish with slender or narrow claws.  Streaked or marbled coloration pattern is most visible on the back, or carapace.  In the wild, most range in color from olive to brown, but in captivity, colors can include tan, red or blue.  

More information: Marbled crayfish

Red Swamp Crayfish

(Procambarus clarkii)

Watch List - Prohibited in Michigan

Red Swamp Crayfish have dark red color with bright red raised spots - they look like small lobsters. They can live in a variety of permanent freshwater habitats. They feed heavily on snails, fish, amphibians, and plants.

More information: Red swamp crayfish

Rusty Crayfish

(Faxonius rusticus)

Restricted in Michigan

Rusty Crayfish are lobster-like with a brown body up to 6 inches in length and oversized claws that have an oval opening when closed and black bands at the tips. Mature crayfish have a dark, rusty spot on each side of the carapace.

More information: Rusty crayfish

Spiny Waterflea

(Bythotrephes longimanus)

Spiny waterfleas are zooplankton (tiny animals) that feed on other zooplankton, decreasing the food supply for native fish.  Spiny waterfleas are very small, approximately 1/4 to 1/2 inch in length. Each has a long, straight tail spine that’s twice the length of its body.

More information: Spiny waterflea


(Cherax destructor)

Prohibited in Michigan

Yabby Crayfish have two enlarged front claws, four pairs of walking legs followed by four pairs of swimmerets (swimming legs). They have a smooth carapace and their color ranges from olive-green to brown, but are sometimes red, yellow, or black.

More information: Yabby