Division of Crustaceans Projects
Burrowing Crayfish
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| Cambarus (Tubericambarus) polychromatus |
The burrowing crayfish project is a multi-year project that investigates the distribution,
life history, and burrow ecology of Indiana primary burrowing crayfish species. The project
is divided into three studies.
-
Base Study:
A baseline study of the four burrowing crayfish in Indiana, including the digger crayfish
Fallicambarus (Creaserinus) fodiens, prairie crayfish Procambarus (Girardiella)
gracilis, and two species within the devil crayfish Cambarus (Lacunicambarus)
diogenes complex. The taxonomy of the diogenes complex is currently being resolved by
Thoma and Simon (in prep.), but currently represents as many as seven and possibly more
species. The two species that occur in Indiana includes the Great Plains mudbug
Cambarus (Lacunicambarus) sp. "A" and painted-hand mudbug
Cambarus (Tubericambarus)
polychromatus. These two species are currently being described by Thoma and Simon
(in prep). The base study objectived are to describe the distribution of (burrowing)
crayfish species in Indiana, determine the relative abundance and density of terrestrial
burrowing crayfish, describe the correlations between burrow habitats with soil and
hydrologic parameters, suggest long-term, statewide monitoring plans (with multi-options
for high, medium, and low cost with associated advantages, and provide an annotated
bibliography of scientific literature relative to the distribution, ecology, and life
history of Indiana's terrestrial burrowing crayfish and the ecology of their burrows.
- Demographics:
The demographics study will document the sex ratios, growth rate and factors that influence
growth, and longevity. These life history parameters will be collected using targeted life
history sampling and information collected during the base study. The life history of the
two species contained within the Cambarus diogenes complex will be selected. Each life
history study will involve a seven-month field period where three sites will be sampled
monthly for each species. A single core site and two satellite sites within the same
watershed will be selected for measuring demographic information. Core locations will not
be disturbed. At satellite locations, specimens will be collected for evaluating the life
history parameters.
- Burrow Ecology:
The burrow ecology study will determine burrow occupation history, determine the depth,
architecture and construction history of the burrow, evaluate the size of the burrow
relative to the size of the occupant crayfish, determine other species found in crayfish
burrows by season, and determine the persistence of individual burrows and terrestrial
burrowing crayfish colonies.
The occupation of burrows by individual crayfish is an important aspect of understanding
the ecology of burrowing species and their associates within the burrow. The morphology,
architecture and construction of burrows may show important correlates between crayfish
morphology and burrow morphology. The use of crayfish burrows by other invertebrate and
vertebrate species suggests that monitoring crayfish burrow associations may reveal
important distribution information about changing land use information for Indiana.
Crayfish are important sentinel species since they structure the function of aquatic and
terrestrial assemblages. Crayfish are important food items for terrestrial wildlife and
aquatic sport species and they are dominant species among aquatic invertebrates.
Targeted "burrow ecology" sites are based on selecting sites distributed in thirds of the
State. These sites will be targeted through discussions with Indiana Department of Natural
Resources, Wildlife Diversity Section staff, academic specialists, and other appropriate
individuals. We will include three different sites per third of the state that will be
sampled over three different seasons.
Twenty burrows will be examined at each associate site using burrow scopes and an
extraction burrow pump. The burrow scope will be used to determine whether a vertebrate
species is present in the burrow. After determining that a vertebrate species is absent,
the burrow pump will be used to extract and filter organisms from the burrow. After use of
the pump additional sampling may require the use of a modified toilet plunger method if
necessary. Ten of these burrows will be selected by targeting those with smooth walls,
grass or insect remains, and those that have fresh piles of sediment that were recently
excavated from within the burrow. These will be referred to as "active burrows." The
other 10 burrows, which do not have such indications of activity, will be referred to as
"inactive burrows" and will be extracted using the burrow pump method once it is determined
that no vertebrates are present.
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