rusty crayfish

(Faxonius rusticus)

Conservation Status
rusty crayfish
Photo by LMG
  IUCN Red List

LC - Least Concern

 
  NatureServe

N5 - Secure

SNA - No Status Rank

 
  Minnesota

Regulated Invasive Species

 
           
           
 
Description
 
 

Rusty crayfish is an exotic, medium-sized to large, freshwater crustacean. It is native to Michigan, Ohio, and Kentucky. It is used extensively by fishermen as bait, and is sold as an aquarium pet. It has been introduced across the United States as unused bait and released aquarium pets. It is now found from Manitoba to Quebec in the north to Tennessee and North Carolina in the south, with disjunct populations in New Mexico and Oregon. There are large populations in many states, including Minnesota. It is considered invasive outside of its native range.

Adults are about 1¾ long when the reach maturity at one year of age. They live three or four years and continue to grow, molting at least twice a year, eventually reaching up to 4 in length not including the claws.

The legs, abdomen, and shield (carapace) covering the front part of the body (cephalothorax) are variable in color. They may be greenish-gray, reddish-brown, or tan. There is usually a rust-colored, thumbprint-like mark on each side of the carapace, and a rust-colored stripe on the upper (dorsal) side of the abdomen. The rust-colored markings may not be present on any individuals in some locations. The long spike-like extension of the carapace that projects forward between the eyes (rostrum) has slightly concave sides.

The claws (chelae) are up to 4 long. They are larger and more robust than those of any other Orconectes species. They often have black bands at the tip. The movable finger (dactylus) on the claw has an S-shaped margin. The gap on the claws when closed is oval.

 
     
 

Size

 
 

Total length: 1¾ to 4

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Shallow water in permanent streams, ponds, and lakes with rocks or logs for cover

 
     
 
Ecology
 
 

Season

 
 

Most active early spring to late fall

 
     
 

Behavior

 
 

They are active in daylight. They are extremely aggressive, out-competing and eliminating other crayfish species when introduced into a new site.

 
     
 

Lifespan

 
 

3 to 4 years

 
     
 

Life Cycle

 
 

Breeding takes place in September and October. Eggs are laid in April and May. Juveniles have a higher metabolic rate, eat twice as much, and develop much faster than native crayfish species of similar size.

 
     
 

Juvenile Food

 
 

Aquatic invertebrates and fish eggs at the bottom on the water body

 
     
 

Adult Food

 
 

Omnivorous and opportunistic. Mostly decomposing organic matter (detritus), but also aquatic plants, animals (especially snails), and insects; other aquatic crustaceans; algae; and fish eggs.

 
     
 
Distribution
 
 

Distribution Map

 

Sources

22, 24, 29, 30, 82.

 
         
         
 

Nativity

 
 

Native to Michigan, Ohio, and Kentucky. Introduced as fishing bait and aquarium pets across the United States.

 
         
 

Occurrence

 
 

Common in eastern Minnesota

 
         
 
Taxonomy
 
  Superclass Multicrustacea (typical Crustaceans)  
  Class Malacostraca (malacostracans)  
  Superorder Eucarida (crabs, crayfish, shrimp, etc.)  
 

Order

Decapoda (crabs, crayfishes, lobsters, prawns, and shrimp)  
 

Suborder

Pleocyemata (crabs, lobsters, shrimp, and allies)  
 

Infraorder

Astacidea (crayfishes and lobsters)  
 

Superfamily

Astacoidea (Northern Hemisphere crayfishes)  
 

Family

Cambaridae  
 

Genus

Faxonius  
       
 

Until recently, this species was included in the genus Orconectes. In 2017 a comprehensive review and updated classification of all the species of crayfish of the world was published (Crandall, K. A., and S. De Grave. 2017). The genus Orconectes was split into two groups. Cave dwelling members remain in the genus Orconectes. Surface dwelling members were placed in the resurrected genus Faxonius.

 
       
 

Synonyms

 
 

Orconectes rusticus

 
       
 

Common Names

 
 

rusty crayfish

 

Crayfish or Crawfish?

The taxonomically correct term for members of the superfamilies Astacoidea and Parastacoidea is crayfish. "Crawfish" is a southern dialectical variant of that word. It is commonly used in the United States and is accepted American English, but it is not used outside the United States.

 

 

 

 

 

 

Glossary

Carapace

The hard, upper (dorsal), shell-like covering (exoskeleton) of the body or at least the thorax of many arthropods and of turtles and tortoises. On crustaceans, it covers the cephalothorax. On spiders, the top of the cephalothorax made from a series of fused sclerites.

 

Cephalothorax

The front part of the body of various arthropods, composed of the head region and the thoracic area fused together. Eyes, legs, and antennae are attached to this part.

 

Rostrum

The stiff, beak-like projection of the carapace or prolongation of the head of an insect, crustacean, or cetacean.

 

 

 
 
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Christa Rittberg

 
    rusty crayfish   rusty crayfish  
           
    rusty crayfish      
 

LMG

 
 

Believed to be a Rusty Crawfish

Young rusty crawfish found near chimney that they produce. ID based upon MN pollution control sight and larger exoskeletons found regularly nearby. Larger live specimens have been found a few years back. This one was about 2.5-3 inches long.

  rusty crayfish  
           
    rusty crayfish   rusty crayfish  
           
 
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Other Videos
 
  WDS - Rusty CrayFish of the Mississippi River
Lampofilm
 
   
 
About

Published on Aug 13, 2011

#1 Wildlife Documentary Series of Amazing Wildlife in Minnesota. This video is great for 3D Animators to do a walk cycle animation. Use this footage as a background in 3DS Max, ect.

 
  Straying Far From Home, Invasive Crayfish Threatens U.S. Waterways
PBS NewsHour
 
   
 
About

Published on Mar 10, 2011

Read the transcript: http://to.pbs.org/gIrXCA

Vince Patton of "Oregon Field Guide" reports on the threat posed to waterways by the eastern crayfish, a species native to the Ohio River that can now be found in 18 states and two Canadian provinces. "Oregon Field Guide" is a production of Oregon Public Broadcasting.

 
  Rusty Crayfish - Orconectes rusticus - Hamilton County, Ohio, USA - December 1, 2012
William Hull
 
   
 
About

Published on Dec 28, 2012

Filmed with underwater camera in the Little Miami River.

 
  Crayfish migration, Ontario, Canada
Aleta Karstad
 
   
 
About

Published on Oct 15, 2017

Possibly the first time a mass migration of crayfish has ever been filmed - under and above water!

The invasive Rusty Crayfish Orconectes rusticus, has hybridized with a native Ontario species, Orconectes propinquus, and in several generations has evolved an overwhelming drive - an obsession - to migrate upstream. In the face of all odds, this crayfish is a compulsive pioneer!

 
  Know Your Invasives: Rusty Crayfish
WiscLimnology
 
   
 
About

Published on Jun 4, 2013

University of Notre Dame graduate student, Lindsey Sargent, explains the tell-tale sign that you're holding an invasive rusty crayfish.

 

 

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  LMG
8/4/2018

Location: New Prague

Young rusty crawfish found near chimney that they produce. ID based upon MN pollution control sight and larger exoskeletons found regularly nearby. Larger live specimens have been found a few years back. This one was about 2.5-3 inches long.

rusty crayfish  
  Christa Rittberg
9/22/2017

Location: Lake Vermillion

rusty crayfish  
  Christa Rittberg
6/24/2016

Location: Lake Vermillion

rusty crayfish  
           
 
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Created: 8/15/2019

Last Updated:

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