• 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.

    Field Guide to Michigan Crayfish

  • Chinese mitten crab Chinese mitten crab

    (Eriocheir sinensis)

    The shell of the Chinese mitten crab can be as large as an adult's palm and has four spines on each side. Crabs are brownish-orange to greenish-brown, and their claws are covered with brown hair, resembling mittens.

  • Fishhook waterflea Fishhook Waterflea

    (Cercopagis pengoi)

    Fishhook waterfleas are zooplankton (tiny animals) that feed on other zooplankton, decreasing the food supply for native fish.  Fishhook waterfleas are very small, approximately 1/4 to 1/2 inch in length, with a translucent body and black eyes. Clusters look like wet cotton

  • Killer Shrimp 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.

  • A marbled crayfish near a piece of pottery in a fish tank 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.  

  • Red Swamp Crayfish Red Swamp Crayfish

    (Procambarus clarkii)

    Detected in Michigan

    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.

  • Rusty Crawfish Rusty Crayfish

    (Orconectes 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.

  • Spiny waterflea 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.

  • Yabby Yabby

    (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.