Illinois Natural History Survey - University of Illinois

Annelida Collection

The Phylum Annelida consists of the segmented worms, including earthworms and their relatives the aquatic oligochaetes, leeches, crayfish worms, suction-feeding worms, and a large number of mostly marine worms known as polychaetes. The INHS Annelida Collection [] is perhaps the largest state collection of freshwater oligochaetes in the country, holding almost 300,000 specimens (over 6,200 lots, or collections). Approximately 206,000 specimens are permanently mounted on microscope slides; the remaining specimens are stored in alcohol in vials and jars. The collection includes representatives of five of the six classes in the Annelida, the exception being the Acanthobdellae, or bristle worms, which includes only a single boreal species. Many worm species that have limited known distributions in North America are included in the collection. Several aquatic annelid species occurring in Illinois are of particular interest in that they are restricted to specific habitats in the state and to a limited number of sites elsewhere in North America.

The brook leech, Glossiphonia complanata.

The geographic scope of the INHS Annelida Collection is about 74% from Illinois; 25% from elsewhere in North America, including collections from 47 states, 5 Canadian provinces, and a few localities in Mexico; and 1% from about a dozen countries outside of North America, including the Caribbean Islands, India, South America, and Sweden. Specific surveys for aquatic annelids as well as general surveys for all aquatic macroinvertebrates conducted by INHS biologists since 1973 have contributed the vast majority of the specimens to the INHS Annelida Collection.

Stephen A. Forbes, the first Chief of the Illinois Natural History Survey, was the first scientist to describe an annelid species from Illinois--and a unique one at that! Haemopis eonops, the American terrestrial leech, was described (as H. terrestris) by Forbes in 1890 from a garden at Normal in McLean County. This species is the only terrestrial leech in North America. This species is our second largest, often reaching a length of over 28 centimeters (11 inches)! Rarely collected from flowing or standing water, H. eonops prefers muddy, bottomland habitats near streams; it feeds primarily on earthworms and other invertebrates, but never on the blood of animals.

Additional information focusing on annelid research in Illinois and around the world is available from the World Wide Web site, The INHS Center for Annelida Resources:

Mark J. Wetzel, Center for Biodiversity

Illinois Natural History Survey

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Champaign, IL 61820

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