Orconectes virilis Rostrum: sides straight Orconectes limosus Chelae: whitish wart-like SPECIES OF ONTARIO CRAYFISH Carapace: prominent tubercules, no black spines on sides of head bands at tips. Abdomen: narrow bars Carapace: narrow areola across abdominal between branchio-cardiac Large potential stream species, segments grooves Most widespread native stream & lake spreading westward from Quebec; species; reddish or brownish, blue claws strongly mottled & speckled Copulatory stylets: Abdomen: paired brown stubby spots on each segment Copulatory stylets: elongate Orconectes virilis Virile Crayfish Orconectes limosus Spinycheek max carapace length 59mm Crayfish Orconectes immunis max carapace length 55mm Cambarus diogenes Rostrum: sides convex Rostrum: rounded Chelae: slender, with a Native pond, slow stream & burrowing species; Large native burrower; Carapace: areola closed notch and tooth midway mottled with irregular light median band brown at midline Carapace: narrow areola Copulatory stylets: broad with small Copulatory stylets: hooked tip - all Cambarus curved species are hooked Orconectes immunis Calico Crayfish Cambarus diogenes Devil Crayfish Orconectes max carapace length 49mm max carapace length 55mm propinquus Rostrum: blade-like ridge Fallicambarus or carina Small, native, stream & lake species; fodiens active in daylight Chelae: smooth, Small native burrower; mottled Carapace: rounded S-shaped rostrum, areola closed, grooves faded Abdomen: broad dark posteriorly (detail) dorsal band Chelae: with tuft of setae Copulatory stylet: stubby at hinge, deep notch at base of movable dactyl Orconectes propinquus Northern Fallicambarus fodiens Digger Crayfish max carapace length 35mm Clearwater max carapace length 39mm Copulatory stylets: Crayfish hooked, closed at tip Orconectes obscurus Small non-native stream & lake Small native stream & lake species; Rostrum: similar to O. species; rusty to lilac uniformly brown/olive or propinquus, rostral carina reddish Cambarus absent bartonii Carapace: dark crescent at back Rostrum: short, squarish Abdomen: without prominent dark band Chelae: only one Orconectes obscurus Allegheny row of tubercles on Cambarus bartonii “Common” Crayfish inner edge of palm Copulatory stylets: with max carapace length 40mm Crayfish distinctive right-angled max carapace length 39mm shoulder Copulatory stylets: short, hooked, open Large non-native stream & lake species; at tip boldly active in daylight Big native stream species with large claws; brown/olive or reddish Orconectes rusticus Rostrum: margins Cambarus robustus slightly concave Chelae: palms concave, Chelae: S-shaped, large two well-developed rows gap of tubercles of equal size on inner edge of palm Carapace: often with Rusty Crayfish rusty “thumbprints” on Orconectes rusticus Cambarus robustus Big Water Copulatory stylets: sides max carapace length 51mm max carapace length 57mm Crayfish hooked, open at tip Copulatory stylets: elongate Design and watercolours © ALETA KARSTAD 2008 Dorsal views of crayfish © Premek Hamr, details of parts from “Crayfishes of Ontario”, Crocker & Barr THE ECOLOGICAL LIFESTYLES IMPORTANCE OF CRAYFISH Some crayfish live permanently in streams and lakes, while others burrow in soil, living for most of Crayfish are our largest freely-mobile invertebrate the year in deep burrows topped with chimneys of animal. They consume a wide variety of foods, and mud balls. Cambarus species are active mostly CRAYFISH are eaten by a great diversity of other animals. at night, while Orconectes are ONTARIO more often seen out from Each crayfish species has a different lifestyle, and a under cover during the day. different effect on the aquatic community it lives in. As At night one sometimes we learn more about their populations, crayfish can sees crayfish up on land, teach us about the health of aquatic environments. foraging or travelling between pools of water. ARE SOME CRAYFISH Crayfish “chimney” made of mud balls DISAPPEARING? Ontario crayfish are subject to all the usual causes of population extinction: HOW TO FIND CRAYFISH habitat destruction invasive aliens You can seek crayfish either passively or pollution, and other mysterious causes. actively. Passive searching consists of identifying the shells or dead individuals Nine crayfish species are known from Ontario, plus seen along shores or in the water, and in one spreading up the St. Lawrence R. from Quebec. the stomachs of fish taken by angling. Burrowing species are eliminated where wetlands Active searching can be almost any and ditches are destroyed, and alien species displace native populations in many waters. method used for monitoring aquatic Crayfish are absent from some degraded urban animals: turning stones with a dipnet, streams, and in some lakes on the Shield, crayfish seining, baited or unbaited minnowtraps, have disappeared without explanation. or dipnetting through aquatic vegetation. number of FIND OUT MORE AT www.crayfishontario.ca KEEP IN MIND THAT TRANSPORTATION OF LIVE CRAYFISH BETWEEN WATER BODIES IS ILLEGAL Because crayfish native distributions are changing so species rapidly, you may be the first to identify and report a THE SHAPE OF CRAYFISH particular species in a place where it has not been known antennule to science. Cambarus bartonii shown carapace as stippled area antenna abdomen rostrum chela FIND OUT telson Distribution of What to record Native Crayfish Tips for observation If you go south there are more Safety and ethics native crayfish species. Only C. bartonii has a Anterior What and when to collect southern range limit in Ontario. copulatory female male stylet (used in Who to contact identification) Copulatory gonopore stylets TO KNOWLEDGE Posterior stylet CONTRIBUTE swimmerets swimmeret CRAYFISH ABOUT ONTARIO.CA WWW.CRAYFISH.