Rusty Crayfish

Initially, the rusty crayfish was introduced to the northern part of the Great Lakes region by fishermen who used them as bait. As the population of rusty crayfish increased, they were harvested for use as fish bait and sold to biological supply companies. This provided impetus to breeding rusty crayfish, and subsequently, releasing them, intentionally or otherwise, into non-native waters.

There is also concern about hybridization of this species with the native northern clearwater crayfish, Orconectes propinquus.

Another common name for crayfish is crawfish or crawdad.

During encounters, rusty crayfish respond to each other depending on the presence of urine. The stronger the odor, which serves as a chemical cue, the shorter in duration and the lesser the aggression during a first agonistic interaction. In addition, urine serves as a recognition cue in that a rusty crayfish that won a first fight over an opponent will recognize that opponent and display dominance during a second aggressive encounter, but the second encounter will be shorter in duration.

Communication Channels: chemical

This species is not afforded any special conservation status.

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Depending on the water temperature, rusty crayfish eggs hatch in 3 to 6 weeks. Young crayfish will undergo 3 to 4 molts while attached to the mother's swimmerets and remain with the mother for several weeks. Once the young have left, they undergo 8 to 10 molts before becoming mature. Maturity usually occurs the following year. Maturity is considered to be at a length of 4.4 cm. After mature, adult males will molt twice annually, and adult females will molt once annually.

These crayfish have displaced native species. They may affect the fisheries industry since they feed heavily on aquatic plants that are important habitat for other invertebrates (foodstuffs for fish), shelter for fish, nesting substrate for fish, and aid in erosion control.

Among agencies concerned about ecosystem management in the Great Lakes region, there is a debate about using rusty crayfish to control Eurasian watermilfoil, an invasive aquatic plant.

Because of its aggressive nature, the rusty crayfish is replacing native Great Lakes crayfish such as Orconectes propinquus. Many organisms live on the exoskeleton and other organisms are internally parasitic in crayfish.

Commensal/Parasitic Species:

• ostracods
• branchiobdellids

The rusty crayfish is a voracious feeder because of its high metabolic rate. Juvenilles feed on benthic invertebrates and fish eggs.

Foods eaten include: aquatic plants, snails, clams, leeches, aquatic insects, other aquatic crustaceans and fish eggs.

The rusty crayfish is an invader species in northern lakes and streams of the Great Lakes region. Native to the Ohio River Basin and Ohio, Kentucky, Tennessee, Indiana, and Illinois, they have expanded their range to Michigan, Minnesota, Wisconsin, Missouri, Iowa, Pennsylvania, New York, New Jersey, New England (except Rhode Island), and parts of Ontario, Canada.

Biogeographic Regions: nearctic (Introduced , Native )

This crayfish inhabits permanent streams, lakes and ponds that have rocky substrate and logs or debris as cover. They will inhabit pools of still water or fast-flowing streams.

Habitat Regions: freshwater

The rusty crayfish typically lives to be 3 to 4 years old.

Rusty crayfish have robust claws unlike other members of the genus Orconectes. They are dark reddish, brown and have dark, rusty spots on each side of the carapace at the base of the cephalothorax.

Range length: 10.2 (high) cm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Rusty crayfish will used their hooked claws in a defensive posture to protect themselves from fish predators.

Known Predators:

• fish

Rusty crayfish mate in late summer, early fall or early spring. Males transfer sperm to the females, but external fertilization does not occur until the water temperature increases. The expelled eggs are fertilized by the sperm and are attached to the swimmerets underneath the crayfish's abdomen with white patches. These white patches are called glair, and and the eggs adhere to this mucus-like substance. From 80 to 575 eggs are laid.

Key Reproductive Features: fertilization (External ); delayed fertilization

Orconectes (Procericambarus) rusticus (Girard)

Cambarus rusticus Girard, 1852:88.—Faxon, 1885a:108, pl. 9: figs. 8, 8′, 8a, 8a′.

Cambarus juvenilis Hagen, 1870:66, pl. 1: figs. 29–33, pl 3: fig. 157. [Syntypes, MCZ 3347 (26 male II, female, 8 juv. male), USNM 4967 (male I), USNM 25830 (male I, female), MHNP (2 male, 2 female). Other types cited by Faxon (1914:418) apparently no longer extant. Type Locality, Kentucky River, Little Hickman, Jessamine County, Kentucky.]

Cambarus juvenalis.—Harris, 1900:271 [erroneous spelling].

Cambarus (Faxonius) rusticus.—Ortmann, 1905c:l12.

Faxonius rusticus.—Williamson, 1907:753 [Faxonius intended as a subgeneric name].—Creaser, 1933a:5.

Cambarus (Faxonius) rusticus rusticus.—Ortmann, 1931:82.

Cambarus (Faxonius) juvenilis.—Ortmann, 1931:84 [in part].

Faxonius juvenilis.—Creaser, 1933a:3 [by implication]; 1962:2 [by implication].

Faxonius (Faxonius) rusticus rusticus.—Creaser, 1933b:21 [by implication].

Orconectes rusticus rusticus.—Hobbs, 1942a:352 [by implication].—Fitzpatrick, 1963:61 [by implication].

Orconectes juvenilis.—Hobbs, 1942a:352 [by implication]; 1974b:32, fig. 147.—Fitzpatrick, 1963:61 [by implication].

Orconectes (Orconectes) rusticus rusticus.—Hobbs, 1942b:154 [by implication].

Orconectes (Orconectes) juvenilis.—Hobbs, 1942b:154 [by implication].

Orconectes rusticus.—Pennak, 1953:465.—Hobbs, 1972b:92, figs. 74c, 75b, d; 1974b:40, fig. 136.—Page, 1985b:412, figs. 145–147.

Orconnectes rusticus.—Threinen, 1958:3 [erroneous spelling].

Faxonius rusticus rusticus.—Creaser, 1962:2 [by implication].

Orconectes Juvenils.—Hobbs and Walton, 1966:136 [erroneous spelling in title].

Orconectes juvenalis.—Merkle, 1969:228 [erroneous spelling].

Orcenectes juvenilis.—Hart and Hart, 1974:45 [erroneous spelling].

Cambarus vusticus.—Lake and Newcombe, 1975:212 [erroneous spelling].

Orconectus rusticus.—DuBois and Sharma, 1977:27 [erroneous spelling].

Procambarus rusticus.—Huner, 1978:4 [lapsus calami].

Cambarus rustrineus rustrineus.—Brodsky, 1981:49 [erroneous spelling].

Orconectes (Procericambarus) rusticus.—Fitzpatrick, 1987a:58.

TYPES.—“Types probably destroyed in the Chicago fire in 1871” (Faxon, 1914:418). Questionable types: USNM 4968 (male II), in very poor condition; ANSP 195 (dry female).

TYPE LOCALITY.—Ohio River at Cincinnati, Hamilton County, Ohio.

RANGE.—Southern Ontario and Michigan to Kentucky and Tennessee; presumably introduced in one or more of the following: New England, Illinois, Iowa, Minnesota, New Mexico, West Virginia, and Wisconsin. (See Page, 1985b:412; Lawton, 1979:90.)

HABITAT.—Streams, ponds, and lakes.

Orconectes (Procericambarus) saxatilis Bouchard and Bouchard

Orconectes saxatilis Bouchard and Bouchard, 1976a:439, fig. 1.

Orconectes (Procericambarus) saxatilis.—Fitzpatrick, 1987a:58.

TYPES.—Holotype, allotype, and morphotype, USNM 146577, 146578, 146579 (male I, female, male II); paratypes, USNM, Raymond W. Bouchard.

TYPE LOCALITY.—Pigeon Creek at Oklahoma State Highway 63, LaFlore County, Oklahoma.

RANGE.—Known only from the type locality, Red River Basin.

HABITAT.—Stream.

Orconectes rusticus (Girard)

Cambarus rusticas Girard, 1852:88.—Faxon, 1885a: 108, pl. 9: figs. 8, 8′, 8a, 8a′.

Cambarus (Faxonius) rusticus.—Ortmann, 1905c: 112.

Faxonius rusticus.—Williamson, 1907:753 [Faxonius intended as a subgeneric name].—Creaser, I933a:5.

Cambarus (Faxonius) rusticus rusticus.—Ortmann, 1931:82.

Faxonius (Faxonius) rusticus rusticus.—Creaser, 1933b21 [by implication].

Orconectes rusticus rusticus—Hobbs, 1942a: 352 [by implication].—Fitzpatrick, 1963:61 [by implication].

Orconectes (Orconectes) rusticus rusticus.—Hobbs, 1942b: 154 [by implication].

Orconectes rusticus.—Spoor, 1955:78.—Hobbs, 1972b:92, figs. 74c, 75b,d.

Orconnectes rusticus.—Threinen, 1958:3 [erroneous spelling].

Faxonius rusticus rusticus.—Creaser, 1962:2 [by implication].

TYPES.—“Types probably destroyed in the Chicago fire in 1871” (Faxon, 1914:418). A questionable type (in very poor condition) is USNM 4968 ( II); also questionable is a dry female, ANSP 195.

TYPE-LOCALITY.—Ohio River at Cincinnati, Hamilton County, Ohio.

RANGE.—Michigan, Ohio, Indiana, Kentucky, Tennessee, and southern Ontario; introduced in Massachusetts.

HABITAT.—Streams, ponds, and lakes.

Orconectes sanbornii erismophorous Hobbs and Fitzpatrick

Orconectes propinquus erismophorous Hobbs and Fitzpatrick, 1962:208, figs. 1–15.

Orconectes sanborni erismophorus.—Fitzpatrick, 1967a:131, figs. 2–18, 24 [erroneous spelling].

Orconectes sanborni erismophorous.—Fitzpatrick, 1967a:160.

Orconectes sanbornii erismophorous [original genitive of species].

TYPES.—Holotype, allotype, and morphotype, USNM 107597, 107598, 107599 (I, , II); paratypes, TU, USNM.

TYPE-LOCALITY.—Crane Nest Creek at Pee Wee, Wirt County, West Virginia.

RANGE.—Little Kanawha River system, West Virginia.

HABITAT.—Streams.