The Most Important Thing:
This key is made up of multiple subkeys. To effectively
run the key, you must first select the appropriate subkey for
your interest. How to do this is explained in "Using the
This is a key and field guide to the Phylum Tardigrada in the
Great Smoky Mountains National Park. It has been
developed as part of the All Taxa Biodiversity Inventory (ATBI) (www.dlia.org).
The key is designed to cover ONLY species in the park, though it
includes approximately 70% of the known eastern U.S.
limno-terrestrial species (H. Meyer pers. com.).
Using it for specimens from other sites could give erroneous
results. Characters for taxa above the species level are
based on a key to limno-terrestrial tardigrades (including
Heterotardigrada and Eutardigrada) by Nelson & McInnes (2002)
and a key to Eutardigrada by Pilato &
Binda (2010). For a current checklist of
all known tardigrade species, and the authorities for each, go to
of Modena Tardigrade Webpage. In our key, images have
been copied from many sources and sometimes modified. In all
cases, the citation for the original illustration is indicated and
these citations can be found in the bibliography.
- Start the key by clicking
here . This opens the key in your
- Among the icons along the top there is a help menu . That opens a webpage from Lucidcentral.org
the group that developed the Lucid
program that runs the key. Among other information it has a
section called “Using the Lucid Player.” This has a
complete set of instructions and examples for using the key.
Looking at the Species:
- Once you are comfortable with the general operation of the
program, start using the key by selecting the entities
(=species) window on the upper right. To expand this to
see all the species, click this icon .
toggles between showing thumbnails of the species and showing
them as a list. As you make selections of feature
(character) states in the key, you may need to re-expand the
species list to see all remaining species. Once the
species list is expanded, you can look at genus and
species web pages and species photos by clicking.
Using the Key:
- Now you are ready to play with the nuts and bolts: a
multichotomous, interactive, pictorial key. The main
thing to know here is that this key is set up as a series of
subkeys. You must select the set of features (characters)
and corresponding entites (species or higher taxa) you want to
investigate. To start, click the icon on the
toolbar. The subsets window opens. For now, click
“Class Characters” and “Classes.”
You must always select a feature (character) subset and its
corresponding entity (species or higher taxon) subset.
A normal progression would be to start with “Class Characters” and
“Classes”. If you determine that your specimen is a
eutardigrade, you could then go to the “Eutardigrade Genera
Characters” and “Eutardigrade Genera” subsets. Once
you have figured out the genus, then you can select the
appropriate genus characters and genus subsets. If you
immediately know the genus, then you can go directly to those
subsets: e.g. if you already know you have a Pseudechiniscus
then select “Pseudechiniscus Characters” and
“Pseudechiniscus.” Each time you start a new subset you must
reset the key .
- Expand the features (character) list by selecting the upper
left window (the feature window), then clicking on the expand
. For each character, you can open a webpage
that explains that character. You can then select one or
more of the character states that corresponds to your
species. The icon
toggles between showing thumbnails of the feature states and
showing them as a list. (Note: to read the entire
caption for each character state you must be in list mode;
captions will be cut off in image mode.) As you select
feature states that you can observe on your specimen, a process
of elimination occurs until you have found the correct
identification. As the species list is narrowed down, you
may have to use the expand icon to see
all species collapsed within higher taxa.
Click here to start the key.
- Data on habitat associations and abundance listed in species
accounts are based on data analyzed as of 15-Oct-2011, including
over 15,000 specimens examined and entered in the ATBI database.
- Data on abundance listed in species accounts uses the
Funding for this project was provided by Discover Life in
Warren Wilson College (www.warren-wilson.edu)
and the Environmental Leadership Center of Warren Wilson College
This key and all original images are copyrighted by Paul J.
Bartels and Diane R. Nelson. Please do not use images
- very abundant >10% of total specimens
- abundant =
5-9.99% of total specimens
1-4.99% of total specimens
- uncommon = 0.5-0.99% of total
= 0.1-0.49% of total specimens
- very rare =
0-0.09% of total specimens
Warren Wilson College
Depts. of Biology & Env. Studies
PO Box 9000
Asheville, NC 28815
East Tennessee State University
Dept. Biological Sciences
East Tennessee State Univ
Johnson City, TN 37614
© P.J. Bartels & D.R. Nelson 2011