Crayfish Guide

**Virile Crayfish (Faxonius virilis)**

Description: Most widespread native stream & lake species; reddish or brownish, blue claws
Max carapace length: 55 mm
Rostrum: Sides straight
Chelae: Whitish wart-like tubercules, no black bands at tips
Carapace: Narrow areola between branchio-cardiac grooves
Abdomen: Paired brown spots on each segment
Copulatory stylets: Elongate

**Calico Crayfish (Faxonius immunis)**

Description: Native pond, slow stream & burrowing species; mottled with irregular light median band
Max carapace length: 49 mm
Rostrum: Sides convex
Chelae: Slender, with a notch and tooth midway
Carapace: Narrow areola
Copulatory stylets: Curved

Calico crayfish, https://onnaturemagazine.com/crayfish-guide.html

**Northern Clearwater Crayfish (Faxonius propinquus)**

Northern clearwater crayfish, https://onnaturemagazine.com/crayfish-guide.html

Description: Small, native, stream & lake species; active in daylight
Max carapace length: 35 mm
Rostrum: Blade-like ridge or carina
Chelae: Smooth, S-shaped
Abdomen: Broad dark dorsal band
Copulatory stylets: Stubby

**Allegheny Crayfish (Faxonius obscurus)**

Description: Small non-native stream & lake species; rusty to lilac
Max carapace length: 40 mm
Rostrum: Similar to O. propinquus, rostral carina absent
Carapace: Dark crescent at back
Abdomen: Without prominent dark band
Copulatory stylets: With distinctive right-angled shoulder

Allegheny crayfish, https://onnaturemagazine.com/crayfish-guide.html

**Rusty Crayfish (Faxonius rusticus)**

Rusty crayfish, https://onnaturemagazine.com/crayfish-guide.html

Description: Large non-native stream & lake species; boldly active in daylight
Max carapace length: 51 mm
Rostrum: Margins slightly concave
Chelae: S-shaped, large gap
Carapace: Often with rusty “thumbprints” on sides
Copulatory stylets: Elongate

**Spinycheek Crayfish (Faxonius limosus)**

Description: Large potential stream species, spreading westward from Quebec; strongly mottled & speckled
Max carapace length: 59 mm
Carapace: Prominent spines on sides of head
Abdomen: Narrow bars across abdominal segments
Copulatory stylets: Stubby

Spiny crayfish, https://onnaturemagazine.com/crayfish-guide.html

**Devil Crayfish (Lacunicambarus diogenes)**

Devil crayfish, https://onnaturemagazine.com/crayfish-guide.html

Description: Large native burrower; brown
Max carapace length: 55 mm
Rostrum: Rounded
Carapace: Areola closed at midline
Copulatory stylets: Broad with small hooked tip – all Cambarus species are hooked

**Digger Crayfish (Creaserinus fodiens)**

Description: Small native burrower; mottled
Max carapace length: 39 mm
Carapace: Rounded rostrum, areola closed, grooves faded posteriorly (detail)
Chelae: With tuft of seta at hinge, deep notch at base of movable dactyl
Copulatory stylets: Hooked, closed at tip

Digger crayfish, https://onnaturemagazine.com/crayfish-guide.html

**“Common” Crayfish (Cambarus bartonii)**

Common crayfish, https://onnaturemagazine.com/crayfish-guide.html

Description: Small native stream & lake species; uniformly brown/olive or reddish
Max carapace length: 39 mm
Rostrum: Short, squarish
Chelae: Only one row of tubercles on inner edge of palm
Copulatory stylets: Short, hooked, open at tip

**Big Water Crayfish (Cambarus robustus)**

Description: Big native stream species with large claws; brown/olive or reddish
Max carapace length: 57 mm
Chelae: Palms concave, two well-developed rows of tubercles of equal size on inner edge of palm
Copulatory stylets: Hooked, open at tip