We carried out an extensive
statewide inventory for crayfishes occurring on the proposed special concern
and watch lists in North Carolina (see lists below). We focused efforts on those species occurring on the special
concern list. Each of these species
either has an extremely limited range or is rare where it occurs (see
distribution maps at www.nccrayfishes.com). Several of these species are endemic to
North Carolina. Secondary emphasis was
given to species occurring on the watch list.
We also collected information for all other crayfish taxa that we
encountered during this statewide inventory.
Some of these species have been recently surveyed to some extent, and we
have included this historical information in the results.
Proposed Special Concern
Cambarus (Cambarus)
lenati (Broad River stream crayfish)
Cambarus (Depressicambarus) catagius (Greensboro
burrowing crayfish)*†
Cambarus
(Puncticambarus) chaugaensis (Oconee stream crayfish)
Cambarus
(Puncticambarus) georgiae (Little Tennessee River crayfish)
Cambarus
(Puncticambarus) parrishi (Hiwassee headwaters crayfish)
Cambarus
(Puncticambarus) spicatus (Broad River spiny crayfish)
Orconectes
(Crockerinus) virginiensis (Chowanoke crayfish)
Orconectes
(Procericambarus) carolinensis (North Carolina spiny crayfish)†
Procambarus
(Ortmannicus) braswelli (Waccamaw crayfish)†
Proposed Watch List
Cambarus
(Cambarus) davidi (Carolinda ladle crayfish)
Cambarus
(Cambarus) sp.
A (howardi?) (Chattahoochee crayfish)
Cambarus
(Hiaticambarus) chasmodactylus (New River crayfish)
Cambarus
(Jugicambarus) carolinus (red burrowing crayfish)*
Cambarus
(Jugicambarus) nodosus (Knotty burrowing crayfish)*
Cambarus
(Puncticambarus) hiwaseensis (Hiwassee crayfish)
Cambarus
(Puncticambarus) reburrus (French Broad River crayfish)†
Cambarus
(Tubericambarus) acanthura (spinytail crayfish)*
Orconectes
(Procericambarus) cristavarius (no common name)
Orconectes
(Procericambarus) spinosus (Tennessee River spiny crayfish)
Procambarus
(Ortmannicus ancylus (Edisto crayfish)
Procambarus
(Ortmannicus blandingii (Santee crayfish)
Procambarus
(Ortmannicus) medialis (Tar River crayfish)†
Procambarus
(Ortmannicus) pearsei (Sandhills crayfish)
Procambarus
(Ortmannicus) plumimanus (Croatan crayfish)†
*denotes primary burrower
†denotes endemic species
Those listed in red were added to the significantly rare
animal list by the NHP (LeGrand et al. 2001) after this project began.
For each of the target
species, our goals were to (1) fill in gaps in the known distribution, (2)
quantify abundance and size of each life history form collected per unit search
time, (3) note specific habitats from which animals were collected, (4) record
species associates present and relative abundances, and (5) quantify seasonal
differences, where possible. This
information should provide a basis for decisions about protection status of
each species inventoried.
In addition, we recorded as
much information as possible during these surveys for the species considered to
be common in North Carolina (12 species) and the following recently described
species: Cambarus (Puncticambarus) hobbsorum Cooper 2001 (Rocky River
crayfish). Further, we recorded information about
occurrences of the 3 exotic species currently known to occur in North Carolina:
Procambarus (Scapulicambarus) clarkii
(Girard 1852) (red swamp crayfish),
Orconectes (Gremicambarus) virilis Hagen 1870 (virile crayfish), and Orconectes (Procericambarus) rusticus
Girard 1852 (rusty crayfish). This
information should be useful for nonindigenous crayfish management (see Lodge
et al. 2000b).
Inventories were conducted
in areas where target species were suspected to occur, based on previous
information and known habitat preferences.
In addition, we extended the search area to define distribution
perimeters. Due to time constraints, we
did not re-visit areas that had been recently surveyed for crayfishes by NCWRC
personnel (e.g., state parks, game lands, and county inventories). This information is included in maps showing
distributions of target species. To
maximize productivity, inventories were conducted statewide according to
weather, water conditions, and scheduling of other projects. GPS units were used to precisely map all
inventory areas, and the habitat conditions at each site were recorded. Survey methods for stream-dwelling
crayfishes included (from most to least often used): (1) hand or net collection
with overturning of rocks or debris (walking or snorkeling); (2) trapping
(minnow traps or pitfall traps, set overnight); (3) electrofishing. Survey methods for burrowers included: (1)
trapping (pitfall or minnow traps, set overnight); (2) digging from burrows;
(3) searches in streams and floodplains at night (with flashlights) and/or on
rainy days. We noted relative efficiencies of collection methods for each
species (see results).
Identifications
were aided by the use of checklists (North America: Hobbs Jr. 1989, North
Carolina: Cooper 2000a, 2000b), keys (Cooper 1998a, 1999a, 1999b, Hobbs
Jr.1991, Jezerinac et al. 1995), species descriptions (Cooper and Cooper 1995,
Cooper 1998b, 2000c, 2000d, 2001, Taylor 2000) and via personal communication
with J.E. Cooper, NC State Museum of Natural Sciences. Where possible, crayfishes were identified
in the field, measured, and released.
Carapace length (tip of rostrum to posterior edge of carapace) was measured
to the nearest 0.1 mm with calipers. A limited number of
specimens of crayfish collected during this project were preserved in 70%
ethanol and maintained as part of reference collections owned by the Nongame
& Endangered Species Program or donated to the NC Museum of Natural
Sciences. Specimens of crayfish
collected during this inventory will be made available to persons interested in
examining them for commensals. These
data are stored in an aquatic database maintained by the Nongame & Endangered
Wildlife Program, are added to the NC Natural Heritage Program database, and
are made available to other agencies upon request.