P. clarkii is 7-25cm and dark red. The claws are long and narrow, and there is typically a blue-grey coloured line along the underside of the tail. Juveniles do not have this red colouring. Additionally, the crayfish has bright red, white (light), or black bumps which are called turbercles.
7-25cm long. Long, narrow claws. Blue-grey coloured long along underside of tail. Bright red, white, or black bumps. Juveniles lack red colouring.
P. clarkii lives in slow moving rivers, lakes, ponds, streams, canals, swamps, and marshes. It is very tolerant and adaptable to a variety of conditions, but prefers small, permanent ponds in colder climates. It is capable of thriving in warm, shallow wetlands. As an invasive, it has the ability to dramatically change plant and animal communities. It can accumulate heavy metals, change water quality and sediment characteristics, damage irrigation, and impact fishing. This species constructs extensive burrows that can destabilize river banks, irrigation canals, and shorelines.
The US has a large aquaculture industry for this crayfish. The aquarium and pond pet trades also likely contributed to the spread of P. clarkii through aquarium release.
Females can carry up to 500 eggs on the underside of their tail.
Inspect any watercraft and recreational equipment used in an affected area to ensure that no crayfish are being transported. Never release captive animals/aquarium pets, or contents into waterbodies. If you see any Red Swamp Crayfish in the wild, report it to NSISC, on iNaturalist, or to Fisheries and Oceans Canada.