Devil Crawfish

Devil crayfish have eyes on movable stalks, allowing them to see in different directions. They use their antennae and chelae, which are covered in tiny hairs, to detect prey and predator animals by sensing water movements. In order to identify and signal readiness for mating to other crayfish, they emit chemical cues, including female pheromones which males sense via their antennules.

Communication Channels: visual ; tactile ; chemical

Other Communication Modes: pheromones

Perception Channels: visual ; tactile ; chemical

According to the IUCN Red List, devil crayfish are of Least Concern (LC) status, as they occupy a wide range of habitats and are highly tolerant to many ecological conditions. However, this species is locally threatened by anthropogenic changes including lake acidification and wetland destruction, though its wide distribution should guarantee its continued survival.

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

After devil crayfish hatch, young cling tightly to their mothers' pleopods using their claws. Young stay with the mother through their first and second molts and most of the third. During the first larval stage, devil crayfish measure about 4.5 mm and are still somewhat embryonic. While in the second larval stage, young detach and swim away from their mothers, returning throughout the second and third stages and remaining near their mothers until they are able to be independent. Juveniles will grow up to 20 mm during the fall, and by their second summer they reach 30 to 35 mm, molting into mature adults.

There are no known adverse effects of devil crayfish on humans.

This species is important to the food industry in a number of ways. It serves as bait, particularly for bass, trout, perch, carp and catfish, and it is also consumed by humans. Devil crayfish keep water quality levels high by eating dead animal and plant material from streams, and they control insect populations as well.

Positive Impacts: food ; controls pest population

Devil crayfish play an important role in the aquatic ecosystem as predators and have been observed to have a net positive effect on prey animal populations. They also function as ecosystem engineers, providing extensive burrowing tunnels and systems throughout aquatic habitats. The larvae of an endangered species (Hines emerald dragonfly, Somatochlora hineana) regularly inhabit devil crayfish burrows in the late summer when their own larval habitats dry up. Devil crayfish are also a threat to populations of this species because they are are known to prey on larvae. Devil crayfish are hosts to a number of parasites, including a leech-like worm (Cambarincola macrodonta), flukeworms and many ostracods.

Ecosystem Impact: creates habitat; biodegradation

Commensal/Parasitic Species:

• Cambarincola macrodonta (Family Branchiobdellidae, Phylum Annelida)
• Cymocythere gonia (Class Ostracoda, Phylum Arthropoda)
• Dactylocythere cryptoteresis (Class Ostracoda, Phylum Arthropoda)
• Dactylocythere coloholca (Class Ostracoda, Phylum Arthropoda)
• Dactylocythere crawfordi (Class Ostracoda, Phylum Arthropoda)
• Dactylocythere crena (Class Ostracoda, Phylum Arthropoda)
• Dactylocythere macroholca (Class Ostracoda, Phylum Arthropoda)
• Dactylocythere prionata (Class Ostracoda, Phylum Arthropoda)
• Uncinocythere zancla (Class Ostracoda, Phylum Arthropoda)
• Trematodes (Phylum Platyhelminthes)

Devil crayfish are scavengers and predators. About 60% of their diet is comprised of living or decaying aquatic vegetation with the other 40% made up of aquatic worms, insects, snails and detritus.

Animal Foods: insects; mollusks; aquatic or marine worms

Plant Foods: leaves

Other Foods: detritus

Primary Diet: carnivore (Insectivore ); omnivore ; detritivore

Devil crayfish live over a wide range, and are perhaps the most widespread of all crayfish in the United States. They have been found in thirty states and the District of Columbia, from Ontario, CA to Texas and from Wyoming to North Carolina, spanning an estimated 2 million km².

Biogeographic Regions: nearctic (Native )

Devil crayfish are burrowing crayfish found primarily in freshwater. Individuals spend most of their life-cycle in underground chambers near marshy and swampy areas of rivers, streams, and ponds. These underground tunnels, each with only one inhabitant, have several openings at the surface, which may have chimneys formed by excavated dirt. These tunnels provide excellent shelter and protection during feeding, mating, egg laying and rearing young, and are deep enough to reach ground water during periods of drought and to avoid freezing winter temperatures. Mean burrow depth ranges from 57.5 cm in autumn to 61.9 cm in spring. Burrows also serve as microhabitats for amphipods and isopods.

Range depth: 0.575 to 0.619 m.

Habitat Regions: temperate ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams

Wetlands: marsh ; swamp

Devil crayfish can live three years or more.

Average lifespan
Status: wild: 3 years.

Devil crayfish are crustaceans related to lobsters (Family Nephropidae) and shrimp (Infraorder Caridea). They have hard exoskeletons that serve as protection from predatory animals. Coloring of these crayfish can vary but they tend to be dark reddish-brown or gray. Bright pastel red and blue individuals have also been found and young crayfish are mostly green, while older individuals are mostly dark brown. Two color variants have been observed in this species, a solid color phase (the most typical) and a striped phase. Devil crayfish resemble miniature lobsters, with spines, ten legs, a rostrum (extending in front of its eyes) with an acumen (pointed apical tip), and a pair of chelae (large claws). Gills are tucked underneath the body. Males differ from females in having a long rostrum with a narrower, more tapered acumen and larger, heavier chelae.

Range length: 40 to 61 mm.

Other Physical Features: ectothermic ; bilateral symmetry

Sexual Dimorphism: sexes shaped differently

This species is prey to more than 200 predatory species, including various fishes, raccoons, Virginia opossum, red foxes, barred owls, Eastern newts, muskrats, crows, spotted salamanders, Eastern painted turtles, Northern water snakes, and red-tailed hawks. Two-thirds of this species' population is consumed by fish. Their burrows, as well as their small size and ability to move quickly, lend individuals some protection from predation. An anti-predator adaptation in this species is a tail-flip response, a rapid flip of the tail segments that allows individuals to quickly flee in the opposite direction. This response also acts as a warning system, signaling others to follow suit.

Known Predators:

• Fishes
• Raccoon (Procyon lotor)
• Virginia opossum (Didelphis virginiana)
• Muskrat (Ondatra zibethicus)
• Red fox (Vulpes vulpes)
• Barred owl (Strix varia)
• Red-tailed hawk (Buteo jamaicensis)
• American crow (Corvus brachyrhynchos)
• Eastern newt (Notophthalmus viridescens)
• Eastern painted turtle (Chrysemys picta picta)
• Spotted salamander (Ambystoma maculatum)
• Northern water snake (Nerodia sipedon)

Devil crayfish are solitary animals, meeting with other individuals only during mating season. Females release pheromones, signaling their readiness to mate. These pheromones are detected by males through their antennules (short antennae). Males court females by touching them with their antennae and claws. Males deposit sperm into females' sperm receptacles during copulation, plugging them afterwards to prevent further mating.

Mating System: polygynandrous (promiscuous)

This species reproduces annually, with breeding occurring predominantly in the fall. Egg-laying occurs in spring after temperatures have risen and photoperiods extend. All devil crayfish eggs are attached to the mother's pleopods for at least four weeks (the composition of the attachment is unknown). Females can lay up to 200 eggs, but only 10% typically survive past the first year.

Breeding interval: Devil crayfish breed once yearly.

Breeding season: Fall

Average number of offspring: 200.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous

While devil crayfish mate in the fall, they wait until the warmer spring temperatures to lay their eggs. After they have been laid, eggs are attached to the mothers until hatching via a hardened mass. After hatching, the larvae are in the first larval stage and firmly attached to their mother's pleopods, living an embryo-like existence. Even after molting into the second and third larval stage, the larvae still rely heavily on their mother because they are incapable of being freely living. However, after the second stage the larvae detach themselves from their mothers, although they return to her often. After molting into the third larval stage, young continue to stay with their mothers for protection until reaching full maturity.

Parental Investment: female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Protecting: Female)

Cambarus (Lacunicambarus) diogenes Girard

Astacus fossor Rafinesque, 1817:42. [Name suppressed by International Commission, Opinion 522. (See Hemming, 1958.)].

Cambarus diogenes Girard, 1852:88.—Huner, 1977:11.—Page, 1985b:434, figs. 167–170.—Pflieger, 1987a:23; 1987b:7.

Cambarus nebrascensis Girard, 1852:91. [Location of types (if extant) unknown. Type locality: Fort Pierre, Nebraska (now in Stanley County, South Dakota).]

Cambarus Nebrascensis.—Hagen, 1870:8.

Cambarus Diogenes.—Hagen, 1870:6.

Cambarus fossor.—Hagen, 1870:8.

Cambarus obesus Hagen, 1870:81, pl. 1: figs. 39–42, pl. 3: fig. 163, pl. 9 [Syntypes: MCZ 195 (2 male I, 1 female), 165 (female), 3361 (male I), 229 (male I), 3363 (male); MHNP (2 dry); St. Petersburg Mus. (= ZIAS), (female) not extant. Type locality: Lawn Ridge, Illinois.]

Cambarus Diogenenes.—Abbott, 1873:83 [erroneous spelling].

Cambarus Diogenes Diogenes.—Faxon, 1884:144 [by implication].

Cambarus diogenes diogenes.—Hay, 1899b:959 [by implication].—Marlow, 1960:229.

S[ambarus] diogenes.—Steele, 1902:11 [erroneous spelling].

Cambarus (Bartonius) diogenes.—Ortmann, 1905c:120; 1906b:402, pl. A: fig. 3, pl. 39: fig. 11, pl. 40: figs. 6, 7.

Bartonius diogenes.—Williamson, 1907:749 [Bartonius intended as a subgeneric name].

Cambarus (Cambarus) diogenes.—Fowler, 1912:341.

Cambarus (Lacunicambarus) diogenes diogenes.—Hobbs, 1969b:110, figs. 2c, 11, 13i, 14i, 20a; 1974b:20, fig. 69.

Cambarus (Lacunacambarus) diogenes diogenes.—Bouchard, 1972b: 103 [erroneous spelling].

Cambarus (Lacunicambarus) diogenes Diogenes.—Hobbs III, Thorp, and Anderson, 1976:5 [lapsus calami].

Cambarus Diogenes diogenes.—Phillips, 1981:17 [lapsus calami].

Cambarus (Depressicambarus) diogenes.—Hobbs, 1986:16 [lapsus calami].

TYPES.—Not known to be extant except for a questionable paratype (female), ANSP.

TYPE LOCALITY.—Vicinity of Washington, D.C.

RANGE.—Very widespread east of the Rockies and south of the Great Lakes, except peninsular Florida and the Alleghenies; not reported northeast of New Jersey in the East and east of western Pennsylvania in the Mississippi drainage system.

HABITAT.—Burrows (primary burrower); often found in ponds or streams in the spring season.

Lacunicambarus diogenes, the devil crawfish, is a species of North American burrowing crayfish found in the Atlantic Coastal Plain and parts of the Piedmont ecoregion from New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia.