Appalachian Crayfish, Cambarus bartonii

OTHER COMMON NAMES

Common crayfish, Appalachian brook crayfish

ETYMOLOGY

Cambarus from kammaros: lobster (Greek) + bartonii: patronym of Barton, possibly the American botanist Benjamin Smith Barton (1766-1815)

Ecology, Habitat, & Behavior

Because Appalachian crayfish live in faster flowing water with more variable water levels, their growth is much slower and more episodic than other crayfish species. This allows them to cope with unpredictable periods of stress and take advantage of periods with better conditions (source). While their range overlaps with the congeneric (in the same genus) big water crayfish, their distributions are almost entirely non-overlapping. In contests between individuals of similar, big water crayfish always were the more aggressive and pushed out. Where the two species have come intact, Appalachian crayfish are being displaced (source).

They live in faster flowing streams and tend to hunker down in shallow burrows under larger boulders. But in siltier environments, they’re also capable of building more extensive burrows with lateral chambers capped with short (1-2 inch tall) chimneys. One facsinating paper reported on a lone juvenile Appalachian crayfish overwintering in a leaf pack in an upland depression with a small cluster of red-backed salamanders (source). Potentially because they are not farmed and have no commercial significance, they are an understudied species.

QUICK FACTS

Avg carapace length: 1.5 inches at maturity, but slow growing so many individuals are smallerLife expectancy: 3-4 yearsAge at maturity: 3rd to 4th summerHabitat: Swift water with rocky substrates# of eggs: <50-75Diet: Omnivorous predator & scavengerNative or non-native: NativeActivity pattern:

Nocturnal

Uses: None, possibly used locally as bait

Life History Event Date/Season
Mating Spring into summer
Fertilization Short delay
Laying Eggs May through June
Young detach from female June, after second molt

Key features for ID + similar species

Can be tough to ID as it lacks distinguishing characteristics. The related big water crayfish is larger,

  1. Small, broad, and blunt rostrum
  2. Single row of tubercles on mesial margin of chelae
ROSTRUM

Small, broad, and blunt, free of accessory projections, acumen small

COLOR/MARKINGS

Orange brown to brownish green, though some blue morphs have been found; generally smooth bodied, mostly free of distinctive markings

CHELAE

Single row of tubercles on mesial margin of chela, dactyl slightly recurved, opening between fingers is large in adults.

AREOLA

Open, moderate areola

Range map for Appalachian Crayfish

Range map based on observations from iNaturalist.org

General Research on Crayfish

  • NOBANIS: Invasive Alien Species Fact Sheet : source
  • Crayfish of the White River Watershed: source
  • Crayfish curriculum for educators: source
  • The Crayfishes of New England: source
  • Species of Ontario Crayfish: source
  • Lecture on Crayfish: video
  • Some aspects of the life histories of three closely related crayfish species, Orconectes obscurus, O. sanborni, and O. propinquus: source
  • Dictionary of crayfish names: source
  • Biological synopsis of the rusty crayfish: source
  • Observations on the life cycle of Procambarus acutus acutus in South Carolina culture ponds: source
  • Natural History of the two Crayfish of Northwestern Iowa, Orconectes virilis and Orconectes immunis: source

Crayfish of Vermont species profiles