Orconectes virilis
Description
- Reddish-brown to olive-brown in colour
- Bumps on the medial, side of its crarpace (hard shell) and along its chelae (large pincher like claw)
- Chelae (large pincher like claw) often have dark specs and orange or reddish tips
- May have paired black marks along its abdomen
- Can inhabit rivers, streams, lakes, marshes & ponds
- Prefers waters with rocky substrate, logs, vegetation, rocks, and other debris to use as cover
- Can survive a temperature range of 0 – 32 celcius
- Native to Missouri, Mississippi, Ohio, Great Lakes drainages
Consequences of invasion
- Compete with and displace native crayfish and fish
- Consume small fish, fish eggs, and tadpoles
- Reduce the abundance and biodiversity of native snail, macroinvertebrate and macrophyte populations
- Increase water turbidity
- Impact irrigation systems and levees as a result of their burrowing near head gates and weir boxes
- Alter the structure and composition of littoral zones
Introduction and spread
- Sold in the pet trade as pets and as prey for predaceous aquarium fishes
- Sold through the bait trade
Integrated pest management options
- Prevention! Don’t Let it Loose!
- Protecting sport fish and regulations that reduce their harvest in order to increase predation on northern crayfish in one potential means of reducing their populations