Identification Guides and Keys
Resources compiled by Lynne M. Witty, Zooplankton Taxonomist and author of the identification guides linked below.
These guides have been used by undergraduate and graduate students internationally for over two decades — if you're using them for thesis work, you're in good company.
Practical Guides
Lynne M. Witty produced two practical identification guides: one for freshwater crustacean zooplankton and another for benthic macroinvertebrate taxonomy. Both guides are available for free download via the links below. They are meant to be used alongside scientific keys (see references listed below).
How to Cite These Guides
For academic work, please use the Laurentian University hosted versions as the citable record. The most current versions, incorporating minor content updates, are available for download above.
Zooplankton guide (note that the first edition was released in 2002) (PDF): Witty, L. M. (2004). Practical guide to identifying freshwater crustacean zooplankton (2nd ed.). Cooperative Freshwater Ecology Unit, Department of Biology, Laurentian University. https://laurentian.ca/assets/files/Living-With-Lakes/Reports/Zooplankton-Guide-to-Taxonomy.pdf
Benthos guide (PDF): Witty, L. M., and Sarrazin-Delay, C. (2014). Illustrated guide to Boreal Shield invertebrate benthos. Cooperative Freshwater Ecology Unit, Vale Living with Lakes Centre, Laurentian University. https://laurentian.ca/assets/files/Living-With-Lakes/Reports/Illustrated-Guide-to-Boreal-Shield-Invertebrate-Benthos-2014.pdf
Scientific Keys
Each of Lynne M. Witty's guides includes a curated list of the key taxonomic literature used for identification. The zooplankton guide draws on authoritative sources for Canadian freshwater Cladocera and Copepoda, from broad identification keys to species-level references. The benthos guide covers freshwater macroinvertebrates across invertebrate groups and insect orders, from general works to specialized family-level keys. Reference lists for both guides are available for download below:
Online Visual Keys
Two excellent visual online keys are highly recommended:
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An Image-Based Key to the Zooplankton of North America (University of New Hampshire) — covers Cladocera, Copepoda, Rotifera, and other groups, with images to aid identification.
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Free-living and Parasitic Copepods of the Laurentian Great Lakes (USGS Great Lakes Science Center, Hudson & Lesko, 2003) — detailed keys and species-level information for Great Lakes Calanoid, Cyclopoid, and Harpacticoid copepods. Useful well beyond the Great Lakes region.
Both are freely accessible with no login required.