Aquatic Annelida (Clitellata) of Great Smoky Mountains National Park, North Carolina and Tennessee, USA

         Hazel Creek, Great Smoky Mountains National Park, 2002 **

This website summarizes our surveys for freshwater oligochaetes (Phylum Annelida, Class Clitellata) and other segmented worms occurring in Great Smoky Mountains National Park (GRSM) (‘the Park’). This is but one of many research and science education projects associated with the All Taxa Biodiversity Inventory program (ATBI) – to identify and document the distribution of all plant, animal, Archaea, and bacterial species in the Park, to study their interactions with one another, and to elevate the public’s knowledge of and interest in biological diversity through educational outreach programs and the integration of K-12 and college students, adult volunteers, and other scientists with ATBI researchers. The ATBI is being underwritten by Discover Life in America, Inc. (DLIA), a non-profit 501 c (3) organization, in cooperation with the Park and the National Park Service. Other partner organizations—the Friends of the Smokies—Friends of Great Smoky Mountains National Park, Great Smoky Mountains Institute at Tremont, and the Southern Appalachian Information Node (SAIN) of the National Biological Information Infrastructure (NBII)—also are working in cooperation with DLIA and GRSM to support a variety of research programs occurring in and adjacent to the Park.

Dr. Becky Nichols, Park Entomologist (NPS-Twin Creeks Research Center) maintains and updates the ATBI Smokies Species Tally for the program. Since the beginning of the ATBI in 1998 (and current as of 08 April 2023) the involvement and cooperation of the ATBI scientists, support personnel, and volunteers has resulted in the discovery of 10,831 species of microbes, fungi, plants, and animals previously unreported from the Park; most remarkablly, this number includes 1,074 species that — based upon material collected from the Park and the dedication of its diverse participants during this incredible program — have been described as new to science. Additional information and updated on species new to the Park and species new to science are summarized on the ATBI Smokies Species Tally website.


The oligochaetous Clitellata (‘Oligochaeta’) represents the most diverse and widely distributed group of annelids in freshwater habitats in North America. While oligochaetes commonly are an important and often dominant component of the benthic community, specimens rarely are identified beyond class or family level because of perceived difficulty in taxonomic resolution. Recent publications have focused on the distribution, ecology, classification, taxonomy, and systematics of aquatic oligochaetes at the North American level (Brinkhurst & Wetzel 1984 (in part); Klemm 1985; Brinkhurst 1986; Kathman & Brinkhurst 1998; Wetzel et al. 2006, 2009). Several other published papers have documented the occurrence of aquatic oligochaetes at the regional level (Spencer 1980, Spencer & Hudson 2003 – Great Lakes; Strayer 1990 – northeastern North America), and state level (Altman 1936, Smith 1984, and Spencer & Wisseman 1993 – Washington; Howmiller & Loden 1976 – Wisconsin; Wetzel 1982 – Kansas; Whitley 1982 – North and South Carolina; Wetzel 1992 – Illinois; Milligan 1998, and Wetzel et al. 2006 – Florida; Wetzel et al. 1999 – Arizona; and Britton & Wetzel 1999 – Hawaii). A few other papers (Webb et al. 1995; Webb et al. 1998; Wetzel & Taylor 2001) provided limited information on the occurrence of aquatic oligochaetes in North American springs and caves. To date, 233 nominal species of freshwater oligochaetes representing four orders, 7 families, and 75 genera are known to occur in North America (Wetzel, Kathman, Fend, & Coates, 2023); of these, at least 9 families, 60 genera, and 125 species (including megadrile earthworm taxa occasionally collected from aquatic and limicolous habitats) are known or thought likely to occur in the southeastern U.S. Prior to this study, no published papers had summarized the distribution of aquatic oligochaetes throughout Great Smoky Mountains National Park, although two papers (Rodriguez & Coates 1996; Reeves & Reynolds 1999) provided limited distribution records for a few oligochaete and other annelid taxa.

Status of this Research

Our initial surveys for aquatic oligochaetes and other annelids in the Park began in September 1999, after receiving funding from DLIA. Small continuance grants received from DLIA in August 2000, March 2001, April 2002, April 2003, April 2004, and April 2006 have provided continuing support of our investigations in the Park. To date we have conducted surveys at 152 aquatic sites in the Park, including streams, springs, seeps, waterfalls, rimstone pools in Gregory Cave, sinks, boglets, ponds, Gum Swamp, and even domestic sewage treatment lagoons. More specific locality information, and summaries of each of our collecting trips, are provided via the categorized hyperlinks in the site navigator bar at the bottom of this page. As of December 2005, over 24 species of aquatic oligochaetes, representing four families and 14 genera, have been identified from these collections. All 24 species are new records for the Great Smoky Mountains National Park; four represent new state records for Tennessee and one represents a new state record for North Carolina. Numerous other specimens collected from aquatic and semi-aquatic  habitats within and adjacent to the Park (including the Blue Ridge Parkway) await identification. These include taxa representing the more taxonomically challenging genera in the families Enchytraeidae and Lumbriculidae, specimens of primarily terrestrial families of earthworms often collected from aquatic and limicolous habitats, and sexually immature individuals of many species. In addition, many branchiobdellidans (aquatic clitellata annelids closely aligned with the oligochaetes that occur as ectosymbionts on [primarily] astacoidean crayfishes), have been collected during our study, but have not yet been identified.

The identification of numerous oligochaete specimens currently being processed will certainly add to the list of species known to occur in the Park. Species identified to date are included in a checklist (now being updated) that will soon be accessible via this website. Annual reports documenting progress on this research have been prepared for DLIA (2000-2004; 2008), and have been summarized in presentations at the annual DLIA meetings (1999-2006) convened in Gatlinburg, TN. Brief summaries of our earlier research in the Park had been summarized in two publications (Wetzel & Morgan 2002a, 2002b); in addition, Reynolds and Wetzel (2004) discussed the distribution of terrestrial oligochaete worms in North America, with reference to the ATBI project and terrestrial oligochaetes occurring in North Carolina and Tennessee. Updates of this paper (Reynolds and Wetzel 2008, 2012) expanded in scope to include earthworm distributions in Mexico, Hawaii, Puerto Rico, and Mexico, and included new records for the southeastern U.S.; maps noting the distribution of all species discussed in this paper were included, as well; a third update is being prepared.

In November 2007, an updated summary of our annelid research and discoveries (Wetzel and Morgan 2007) was published in a special issue of Southeastern Naturalistwhich focuses on the on diverse research and educational programs affiliated with the ATBI in the Park; a full citation for this paper (and special issue) is included in the Literature Cited section of this webpage.

In December 2007 Steve Fend and Dave Lenat (2007) published a paper in which they described two genera and three species of aquatic oligochaetes new two science, all in the family Lumbriculidae; a specimen we had collected from Forney Creek in April 2003 was used in the description for one of those species, Martinidrilus carolinensis Fend & Lenat, 2007; this new species has been added to the preliminary checklist of aquatic oligochaetes in the Park, HERE.

2003 Summary

Funding received in early April 2003 supported two collecting trips to the Park —April/May and September 2003. During the first visit (27 April-1 May), we surveyed 12 streams and four spring/seep areas. On Sunday 27 April, we had the opportunity to participate in a DLIA-sponsored public outreach opportunity—”Take a Llama to Lunch” hike along Lynn Camp Prong, located SE of the Great Smoky Mountains Institute at Tremont. During this hike, DLIA Administrator Jeanie Hilten and NPS/ATBI entomologist Becky Nichols introduced 14 participants to the ATBI project and several of the current research projects being funded by DLIA, including our surveys for aquatic oligochaetes and other macroinvertebrates. Local naturalist and author Ila Hatter (Stecoah, NC) shared her botanical expertise with participants, and photographer Kevin Fitz Patrick recorded participants’ experiences for the ATBI project. Llamas were provided by Sandy Sgrillo of Smoky Mountains Llama Treks—and were quite well-behaved during this outing.

We also ‘survived’ the earthquake on Tuesday, 29 April (4:59.39 EST; magnitude: 4.6) while camping along Forney Creek (Fontana Reservoir drainage) on the south side of the Park. The epicenter of this earthquake (in NE Alabama, 25 km ENE of Fort Payne; coordinates:  34.494°N, 85.629°W), was located at the southern end of the Eastern Tennessee Seismic Zone, which extends in a northeasterly direction from NE Alabama to the southwestern tip of West Virginia—skirting the west side of the Park. Additional information on this earthquake is available on the website accessible via the hyperlink from the highlighted word ‘earthquake’, above.

During our second visit to the Park (20-26 September) we surveyed 13 streams, 1 spring, and the Smokemont sewage treatment lagoon. On Monday, 22 September, we had the opportunity to work with two Cherokee High School science classes at Mingus Creek, demonstrating our field methodologies by involving them in the collection and study of live aquatic invertebrates; we were assisted by Cherokee HS Forestry instructor Miki Powell, and NPS personnel Susan Sachs and Jonathan Mays, who regularly plan and conduct public education and outreach activities in the Park.

Highlights of our visits to the Park in 2002 and 2003, including pictures of several sites and of our public education and outreach activities, are available via two hyperlinks (”Project Highlights”) in the navigator at the bottom of this page.

2004 Summary

A proposal to continue work on this project was submitted to DLIA on 13 February 2004; that proposal was funded on 2 April 2004. Two collecting trips to the Park were planned for May and September 2004, concentrating on low gradient streams as well as springs and wetland habitats. In addition, we also would be increasing our efforts to collect crayfishes from all sites—to further document the distribution of this group in the Park, and to obtain branchiobdellidans (ecto-commensal worms closely aligned with the oligochaetes) in anticipation of funding from the National Science Foundation to conduct research on this group.

Our first trip in 2004 was conducted 15-21 May; during this visit, 14 aquatic and two terrestrial sites were surveyed. Our second field trip, originally scheduled for September but postponed because of elevated levels of precipitation in and adjacent to the Park from hurricanes Frances and Ivan, was conducted 18-22 October; during this visit, three spring/seep areas and 10 streams were surveyed. A highlight of this trip was the opportunity to work with Cherokee High School science students during both laboratory and field sessions on Monday 18 October, involving them in the collection and study of aquatic invertebrates during a class field trip to the Appalachian Highlands Science Learning Center at Purchase Knob. We were assisted during this field trip by class instructor Miki Powell, and NPS science education outreach personnel Susan Sachs, Jonathan Mays, and Jennifer Krell.

Continuing research in 2005 and beyond

Subject to receipt of future funding, our plan is to continue with this research for at least 2-3 more years, concentrating on: 1) low gradient stream and extant standing water (pond, pothole, bog, marsh, wetland) sites, 2) revisits to sites from which immature specimens representing uncommon to rare genera were found, 3) additional spring/seep habitats, and 4) collection of crayfishes in order to obtain ectocommensal branchiobdellidan worms. Other public outreach and educational opportunities are also of interest to us. Our surveys in 2005 were completed 20-27 August, with focus on 13 streams and groundwater habitats (springs, seeps) in the Tremont, Cosby, and Deep Creek areas, and also along the Foothills Parkway (NW). During this visit, we also had an opportunity to demonstrate our field techniques (collections for aquatic macroinvertebrates and field water quality monitoring) for staff working at the Great Smoky Mountain Institute at Tremont (GSMIT); we thank Jennifer Arnold, Michelle Prysby, and Ken Voorhis of the GSMIT for arranging this opportunity for us, and extend our appreciation to the Woodpickers for an evening of wonderful bluegrass and folk music.

Just prior to our August 2005 visit, we secured an NPS permit (BLRI-2005-SCI-0027) so we could collect annelids from selected spring and seep areas along the Blue Ridge Parkway (BRP) just ‘south’ and ‘north’ of the Waterrock Knob Visitor Center in North Carolina; these sites have been investigated recently by Dr. David Lenat and Skip Call, who are conducting an inventory of aquatic macrinvertebrates in similar habitats associated with the BRP for the NPS; their findings of oligochaetes, and in particular one taxon that unique from all other congeners, prompted our visit to attempt collection of other specimens that hopefully will aid in its identification. We thank Dr. Chris Ulrey (plant ecologist and permit coordinator for the BRP) for his assistance in securing a collecting permit on short notice.


All research associated with this project in the GSMNP has complied with and was conducted under the following Scientific Research and Collecting Permits issued by the USDI-NPS to Mark J. Wetzel: GRSM-99-124; GRSM-00-133; GRSM-2001-SCI-0094, GRSM-2002-SCI-0015 [2002-2004], and GRSM-2005-SCI-0020 [valid 1 April 2005-31 March 2008]. Investigator Annual Reports (IAR’s) summarizing the objectives, findings, and results of our research have been submitted to the NPS, in partial fulfillment of permit requirements. Recent IAR’s associated with research conducted under permits issued by the NPS can be searched for and viewed online; you do not need to sign in/use a password if you are just interested in reading previously submitted (and posted) IARs.

Related Annelid Studies in the Park


Drs. Donald J. Klemm (U.S.Environmental Protection Agency, Cincinnati, OH) and William E. Moser (Division of Worms, National Museum of Natural History – Smithsonian Institution, Washington, DC) are the primary systematists working with freshwater leeches for this project; their research also is supported by small grants received from DLIA. Drs. Klemm and Moser are currently working on an illustrated key to leeches occurring in the southeastern United States, including those recently collected during their DLIA-funded research in the Park. Moser et al. (2005) published a paper on the life history and distribution of Oligobdella biannulata, a leech associated with salamanders (genus Desmognathus) that occurs in the Park, and elsewhere in the southeastern U.S.

A website entitled Classification and Checklist of the Leeches (Phylum Annelida: Class Clitellata: Subclass Hirudinida) occurring in North America North of Mexico was compiled by Don Klemm, Bill Moser, and Mark Wetzel, and first posted in July 2007; this site is updated regularly.

Terrestrial Oligochaetes

Dr. Samuel W. James (Kansas University Natural History Museum and Biodiversity Research Center) has been surveying the Park for terrestrial oligochaetes, also underwritten by small grants from DLIA. In particular, Dr. James has been searching for specimens of an exceptionally large earthworm in the genus Diplocardia – a species new to science. Dr. James has also discovered another earthworm species new to science in the genus Bimastos, and another possibly new species in the genus Diplocardia. Of the 22 earthworm species occurring in the Park, 10 are considered exotic, including the invasive Amynthas agrestis (Goto & Hatai, 1899) (Family Megascolecidae); its occurrence was recently documented by Dr. Paul F. Hendrix. At the 10th annual DLIA-ATBI meeting in December 2006, Bruce Snyder presented a summary of his work (in collaboration with Dr. Hendrix) on the status of invasive earthworms in the Park, as well as his work with earthworm and millipede diversity, also in the Park. Amynthas agrestis is one of 45 non-native terrestrial oligochaetes known to occur in North America; to date, it has been reported from 23 U.S. states, Ontario, Canada, and Mexico, but has not yet been reported from Hawaii, Puerto Rico, or Bermuda (Reynolds & Wetzel 2008, 2012; Reynolds 2018, 2022).

I (MJW) also serve as an ATBI TWIG (taxonomic working group) leader for the Vermes TWIG (worms and worm-like groups—Annelida [true-segmented worms: Aeolosomatida, Hirudinida, aquatic and terrestrial oligochaetes], Platyhelminthes [flatworms: Turbellaria], and Nematomorpha [horsehair worms]).

This research adheres as closely as possible to the tenets of the ATBI Science Plan.

Please familiarize yourself with the site navigation bar at the bottom of this page; from there you can access numerous aspects of this research on aquatic oligochaetes in the Park, including project highlights, site locality information and map of the Park; field and lab methodologies; progress; links to sponsors of this research; an acknowledgment page recognizing the numerous people whose collective assistance has been instrumental in the conduct of this research; publications and presentations summarizing progress on this research; a literature cited section (with full citations for references in the text above and on other pages associated with this website); and short-and long-term goals of this project.

I encourage you to visit the Discover Life in America, Inc. (DLIA) website for additional information on the All Taxa Biodiversity Inventory (ATBI) program, the administrative staff of DLIA, summaries of ongoing research, and opportunities for public involvement in research and education in the Park. Please Note: The new DLIA / ATBI website has been expanded extensively over the two years; please visit and familiarize yourself with its own ‘virtual’ diversity of information and resources!

Many suggestions that will guide you towards involvement in the ATBI, and instructions on the various ways you may contribute to this ongoing program — whether it be monetary donations, in-kind contributions, leveraged support, or volunteer participation—are provided on the DLIA and ATBI websites; we encourage your involvement!

** Aquatic annelid specimens collected from this Hazel Creek site in 2002 include several oligochaete and branchiobdellidan taxa.

[page update:  18,26 November 2021;21jun2022; 01,21Jan,07,08Apr2023; mjw]