The following species lists were compiled by Mark J. Wetzel, Ph.D., who headed the INHS Annelid Collection for over 35 years and dedicated his career to studying aquatic and terrestrial annelids. These lists — now preserved here following the retirement of his personal website — reflect decades of his efforts to document and classify annelids from Illinois, North America, and several U.S. national parks. Some of the data is still in progress, but continues to serve as a valuable resource for researchers studying oligochaetes, leeches, enchytraeids, and other clitellate worms.
Aquatic Annelids (Clitellata) of Great Smoky Mountains National Park (North Carolina and Tennessee)
This preliminary list presents aquatic oligochaetes and other aquatic and semi-aquatic annelids recorded in and adjacent to Great Smoky Mountains National Park. It includes species verified from the park as well as others expected to occur based on their known distributions across the southeastern United States.
View the Great Smoky Mountains National Park species list.
Aquatic Annelids of The Colorado River, Grand Canyon National Park
This preliminary list documents aquatic and semi-aquatic annelids recorded from the Colorado River and its tributaries within Grand Canyon National Park. It represents the first detailed account of these organisms in the region and is based on specimens collected between 1991 and 2006.
View the Colorado River species list.
Aquatic Annelids of Illinois
This list builds on Mark J. Wetzel’s 1992 review of aquatic annelids in Illinois, which documented 132 species across 71 genera and 15 families. The list has since been updated to include additional species found in the state, incorporate recent nomenclatural and systematic changes, and correct past date-of-publication errors. It also reflects current work on phylogeny and classification of aquatic annelids in Illinois.
View the Aquatic Annelids of Illinois species list.
Freshwater Oligochaetes (Annelida: Clitellata) of North America North of Mexico
Compiled by Mark J. Wetzel, R.D. Kathman, S.V. Fend, and K.A. Coates, this list presents the current classification and accepted names for freshwater oligochaetes occurring in North America north of Mexico. It is presented as an interim step toward a major revision and update of information available through the Integrated Taxonomic Information System (ITIS), for which Wetzel had long served as a steward. The project corrects nomenclatural discrepancies, incorporates recent synonymies, and provides supporting references for all valid taxa. The list also functions as the source of accepted species names for the Society for Freshwater Science’s Taxonomic Certification Program.
Visit the Freshwater Oligochaetes of North America North of Mexico species list.
Leeches (Annelida: Clitellata: Hirundinida) of North America North of Mexico
This list summarizes the current classification and list of freshwater leeches occurring in North America north of Mexico. It includes three orders, five suborders, ten families, nineteen genera, and more than ninety-four nominal species documented from published records. The list is derived from peer-reviewed literature and excludes unpublished records, some of which may represent new distributions, species, and ecological affiliations.
Visit the Leeches of North America North of Mexico species list.
Earthworms of Illinois
This list summarizes the known earthworms of Illinois. It includes forty-two species in eighteen genera and six families, based on published and unpublished records, field notes, museum collections, and recent field collections. Twenty-two of these species are considered introduced in North America — four of which are known only from greenhouses or other indoor cultures in Illinois — and twenty are considered native.
Visit the Earthworms of Illinois species list.
Enchytraeids of North America
This list summarizes the current classification of enchytraeidae and propappidae (Clitellata: Enchytraeida) known from the United States and Canada. It includes marine, estuarine, freshwater, and terrestrial species recorded within the study area and presents each family, genus, and species in a conservative manner — reflecting only consistently supported parts of the annelid phylogeny — along with their author and year.
Visit the Enchytraeids of North America species list.