Key to the Freshwater Leeches of North America

modified from Sawyer, 1986

 

Hirudiniformes
1External copulatory gland pores on venter, located about 10-11 annuli posterior to the male gonopore 2*
- No copulatory gland pores 10-11 annuli behind male gonopore 5*
2Gonopores separated by 2-2.5 annuli3*
-Gonopores separated by more than four annuli, usually five 4*
3Dorsum with about 21 metameric red or orange dots at mid-line:
With 24 copulatory gland pores (two rows of two groups, containing six gland pores each); known only from eastern Massachusetts (Smith 1977)
Macrobdella sestertia Whitman, 1886
-Dorsum lacking red or orange dots:
With eight copulatory gland pores (two rows of four); widely distributed throughout southeastern states.
Macrobdella ditetra Moore, 1953
4Four copulatory gland pores (two rows of two):
Widely distributed throughout northern states and Canada.
Macrobdella decora (Say, 1824)
- Six copulatory gland pores (three transverse rows of two each):
This form occurs at the southern periphery of the range of its very closely allied species Macrobdella decora, near the Missouri-Kansas border; Parallel modifications of the copulatory pores occur at the extreme southern Appalachian end of the range of M decora (Sawyer and Pass 1972).
Macrobdella diplotertia Meyer, 1975
5Glandular area around gonopores, the latter obscured by deep copulatory depressions:
Dorsum with a yelllow or brown stripe; gonopores separated by 3-4 annuli but difficult to see; widely distributed in southern states; A related form, the genotype Philobdella floridana (Verrill 1874), is inadequately distinguished from P gracilis, with which it is probably conspecific; type locality; Lake Okeechobee, Florida
Philobdella gracilis Moore, 1901
- No glandular area around gonopores; gonopores distinct and separated by five or more annuli 6*
6Gonopores separated by five (or 5.5) annuli
Female gonopres small and not nipple-like
7*
- Gonopores separated by seven (or 6.5) annuli:
Female gonopore large, conical, nipple-like in adults, flattened in juveniles
Haemopis septagon Sawyer and Shelley, 1976
727 distinct annuli from oral cavity to annulus (XIb6) bearing male gonopores, annuli VIIa3 and VIIIa1 completely subdivided ventrally Haemopis terrestris (Forbes, 1890)
-25 distinct annuli from oral cavity to annulus (XIb6) bearing male gonopores, annuli VIIa3 and VIIIa1 not subdivided ventrally 8*
8With jaws and teeth 9*
- Lacking teeth and distinct jaws 11*
9Dorsal surface with median dark stripe:
Body firm in life; juveniles with metameric dark transverse bands.
Haemopis kingi Mathers, 1954
- No mid-dorsal dark stripe
Irregularly pigmented or unicolour; body limp in life.
10*
10Flexion of penis sheath at XII-XIII:
Caudal sucker large, about 0.75 width of body; recorded only from Iowa and Minnesota.
Haemopis lateromaculata Mathers, 1963
-Flexion of penis sheath at XVII (XVI-XVIII):
Caudal sucker relatively small, about 0.5 width of body; very common and widely distributed throughout northern United States and Canada; two colour morphs; (i) olive green with heavy mottling dorsally and ventrally; (ii) uniform slate grey with a few irregular black blotches, resembling H grandis
Haemopis marmorata (Say, 1824)
11Margin of oral sucker thick, rounded, aperture transverse, the lower margin anteriorly convex
Lower surface of velum closely and finely papillate; pharynx with 15 longitudinal folds; flexion of penis sheath at XVI.
Haemopis plumbea Moore, 1912
-Margin of oral sucker thin, aperture elongate and arched, the lower margin sharply concave:
Lower surface of velum smooth; pharynx with 12 longitudinal folds; flexion of penish sheath at XVI
Haemopis grandis (Verrill, 1874)
Erpobdelliformes
1Ejaculatory duct with a preatrial loop extending anteriorly to ganglion XI 2*
-Ejaculatory duct without a preatrial loop extending to ganglion XI 8*
2All mid-body annuli distinctly subdivided:
Atrial horns spirally coiled like a ram's horn; distributed only in the northern tier of states and Canada.
Erpobdella obscura Verrill, 1872
-All mid-body annuli not subdivided
Atrial horns simple, not spirally coiled
3*
3Gonopores separated by two annuli, male gonopores in furrow 4*
-Gonopores separated by 2.5 or more annuli, male usually on annulus and not in furrow 5*
4Atrial horns anteriorly directed, with tendency toward the medial:
With two or four longitudinal rows of black pigment concentrations; male gonopore remarkably large in adults; a very common species throughout United States, Canada, and into Mexico; E montezuma from Arizona has posterior crop caeca (Davies, Singhal, and Blinn, 1985).
Erpobdella punctata (Leidy, 1870)
- Atrial horns directed anteriolaterally, no tendency toward the medial:
A poorly charaterized Californian species; in spite of its name some, especially young, individuals possess three pairs of eyes (Gadler and Olson, 1985); This has no bearing on the validity of its name.
Erpobdella anoculata (Moore, 1898)
5Eyes three pairs:
Male pore very large, on annulus; a coastal plain form of E punctata punctata, from Carolinas
Erpobdella coastalis Sawyer and Shelley, 1976
6Eyes four pairs:
Male pore only moderately large; from northern states and Canada.
7*
7Dorsum with variable dark mid-dorsal stripe:
Dorsum greenish, heavily mottled; gonopores separated by 3.5-4 annuli.
Erpobdella dubia (Moore and Meyer, 1951), n comb.
- No mid-dorsal stripe:
Dorsum unpigmented or colour uniformly smokey grey; gonopores separated by 2.5-3.5 annuli.
Erpobdella parva (Moore, 1912),
8Gonopores separated by two annuli 9*
- Gonopores separated by three or four annuli 10*
9Atrial horns directed medially:
Body cream-coloured with scattered small black chromatophores irregularly dispersed, not metameric; especially pigmented around mouth; mouth large, elliptical, with thickened anterior lips; typically found in coastal plain of Carolinas
Erpobdella melanostoma Sawyer and Shelley, 1976
- Atrial horns directed anteriorly or laterally, not distinctly medially:
Body uniformly smokey grey, lacking pigment entirely or sometimes with minute black pigment; occurs in northern states and Canada; A closely related form, E bucera Moore 1949, is localized in south-eastern Michigan; atrial horns projecting more laterally than E fervida
Erpobdella fervida (Verrill, 1874)
10Gonopores separated by three annnuli: Erpobdella microstoma (Moore, 1901)
- Gonopores separated by four annuli: Erpobdella tetragon Sawyer and Shelley, 1976
Glossiphoniidae
1Eyes four pairs (Theromyzon)
Three nominal species recognized here based on number of annuli between gonopores; in need of anatomical examination of the vaginal region of the female system (see Livanow 1902).
2*
- Eyes one, two or three pairs 4*
2Gonopores separated by two annuli: Theromyzon bifarum
- Gonopores separated by three or four annuli 3*
3Gonopores separated by three annuli:
The common species of the western United States and Canada.
Theromyzon trizonare
-Gonopores separated by four annuli:
Common in Europe but its presence in North America requires re-evaluation based on criteria other than gonopores.
Theromyzon tessulatum (OF Muller, 1774)
4Mid-body segments biannulate:
Caudal sucker large, conspicuous; known from mountains of North and South Carolina; permanent parasites on salamanders.
Placobdella biannulata (Moore, 1900)
- Mid-body segments tri-annulate5*
5Eyes three distinct pairs
Placobdella hollensis has accessory eyes and not included here.
6*
-Eyes one or two pairs 8*
6Gonopores share a common pore:
Three pairs of eyes, with a significantly smaller space between the eyes of the first pair than that between pairs 2 and 3; size small, less than 15 mm at rest; egg sacs attached directly to venter; colour whitish; six pairs crop caeca; A closely related form, A swampina (Bosc, 1802), lives in coastal Carolinas (Sawyer and Shelley 1976).
Alboglossiphonia heteroclita (Linnaeus, 1761)
- Gonopores separated by two annuli
Three pairs of eyes, all about equidistant from each other; size moderate, about 25 mm; egg sacs attached to substrate; darkly pigmented, with some dorsal papillae; seven pairs crop caeca; two conspicuous paramedian lines of brown pigmentation.
7*
7Dorsum with conspicuous tubercles on second (2a) and third (a3) annuli of each mid-body segment:
In North America known only from Alaska and British Columbia (Klemm 1981)
Glossiphonia verrucata (Fr Muller, 1844)
-Dorsum relatively smooth, lacking tubercles on the third (a3) annulus:
Common throughout North America except in southeastern states; this species, originally described as elegans Verrill, 1872, differs from its European namesake by having seven, instead of six, pairs of crop caeca.
Glossiphonia complanata (Linnaeus, 1758).
8Anterior sucker distinct from body
Temporary parasites of fish (Shelley and Braswell 1981)
9*
- Anterior sucker not distinct from body 10*
9Dorsum with three prominent ridges or keels: Placobdella montifera Moore, 1906
- Dorsum smooth, lacking ridges: Placobdella nuchalis Sawyer and Shelley, 1976
10Eyes distinctly separated, usually by the diameter of one eye or more
Crop caeca six or fewer pairs; no mycetomes; predaceous on invertebrates; eyes single, not compound; gonopores separated by one or no annuli.
11*
-Eyes close together or touching
Crop caeca seven pairs; one pair mycetomes; parasitic on vertebrates; eyes in some species compound; gonopores separated by two annuli.
17*
11Brown plaque (=scute) in mid-dorsal neck region:
Nearly indisitinguishable from the European H stagnalis
Helobdella modesta Verril
- No plaque in neck region 12*
12Gonopores share a common pore:
Dorsal and ventral surfaces heavily pigmented with uniform greyish-blue chromatophores and with thin dark paramedial lines extending to neck region; body opaque; dorsum smooth; a northern species widely distributed throughout Canada, and in Michigan
Marvinmeyeria lucida (Moore, 1954)
- Gonopores separated by one annulus 13*
13Crop caeca represented only by one short posterior pair ('post-caeca'), to XX/XXI:
Body elongated, subcylindrical; lateral margins of body almost parallel; translucent, unpigmented body; caudal sucker small, terminal.
Helobdella elongata (Castle, 1900)
-Crop caeca with six pairs crop caeca
Body leaf-shaped to sublanceolate; caudal sucker ventral
14*
14Dorsum with distinct papillae or tubercles 15*
-Dorsum smooth, lacking papillae or tubercles 16*
15Dorsum roughly and heavily papillated:
Dorsum with many whitish, rounded papillae arranged in 5-9 longitudinal series on each neural (a2) annulus; occurs in Great Lakes region.
Helobdella papillata (Moore, 1906)
- Dorsum typically with three series of small black-tipped papillae:
A notoriously variable species representing a complex of forms; typically with four series of metameric white dots on neural annulus external to papillae; no mid-dorsal dots; atypical forms with longitudinal stripes of with reduced number of papillae; Often given the name H triserialis which is strictly endemic to South America.
Helobdella papillata (E Blanchard, 1849)
16Dorsum with distinct transverse pigment patterns:
Dorsum with transverse rusty-brown bands alternating with white bands, the latter consisting of 8-10 confluent white dots on neural annulus; no longitudinal pattern; pigment fades in ethanol; known from western Great Lakes states
Helobdella transversa Sawyer, 1972
- Dorsum with longitudinal pigment patterns:
Dorsum with six major longitudinal white stripes alternating with six coffee-brown stripes, including a mid-dorsal band; no transverse pattern; pigment remaining after preservation in ethanol; a variable species inadequately distinguished from Helobdella triserialis complex with which it is closely allied.
Helobdella fusca (Castle, 1900)
- Dorsum with longitudinal pigment patterns:
Dorsum with fine coffee-brown stripes, excluding a mid-dorsal band; no transverse pattern
Helobdella lineata (Verril)
17Salivary glands diffuse, in anterior two-thirds of body
Caudal sucker typically modified for semipermanent attachment to host (ie large, on peduncle or with rim of specialized papillae); body typically rounded, soft-bodied, unicoloured; semipermanent parasites on fish or amphibians.
18*
- Salivary glands compact, typically two pairs which insert at base of proboscis
Caudal sucker not remarkable, ventral; body typically flattened, firm-bodied and with distinct pigment patterns; temporary parasites on amphibians and reptiles.
20*
18Anus anteriorly displaced, at XXIII/XXIV:
Permanent parasite in gill-chamber of fish, especially the drum, Aplodinotus grunniens; caudal sucker set off from body by a narrow peduncle.
Placobdella pediculata (Hemingway, 1908),
- Anus in normal position on segment XXVII
Caudal sucker relatively enlarged, rim moderately thick, bulbous and set off from body by a short peduncle.
19*
19Rim of caudal sucker with about 30 retractile digitate processes which when everted project finger-like along inner margin of sucker cavity:
Usually found in gill-chambers of fish; mid-body segments three-annulate with tendency toward secondary subdivision; An aberrant form, A annectens Moore 1906, is characterized by about 60 digitiform processes, but has not been found since original description
Actinobdella inequiannulata Moore, 1901
-Rim of caudal sucker lacking digitate processes:
Known only from Ozark hellbender Crypotbranchus in Missouri.
Actinobdella cryptobranchii (Johnson and Klemm, 1977)
20Accessory eyes present:
Two pairs of variable concentrations of dark pigment situated two and five annuli behind the single functional pair of eyes, giving the impression of three pairs of eyes
Placobdella hollensis (Whitman, 1892)
- No accessory eyes 21*
21Dorsum with conspicuous white genital and anal patches
White ring in neck region
22*
- Dorsum without white patches 24*
22Dorsum smooth, no papillae or tubercles
Body flattened
23*
-Dorsum with three series of usually dark-tipped papillae:
Body convex, thick, opaque; a variable species, incompletely characterized; known hosts: fish (Amin 1981).
Placobdella phalera (Graf, 1899), n comb
23Five longitudinal rows of white prominences surrounded by yellowish dots equidistant longitudinally and transversely;
No true dark-tipped papillae; body ovate-lanceolate; known from Michigan.
Placobdella michiganensis (Sawyer, 1972)
-Lacking the five longitudinal rows of white prominences:
No true dark-tipped papillae; body lanceolate; lightly pigmented with small brown, cutaneous chromatophores; or pigmented with a broken longitudinal median stripe and two rows of submarginal spots; widespread in south-eastern United States.
Placobdella translucens Sawyer and Shelley, 1976
24Dorsum smooth, with no (or only inconspicuous) papillae 25*
- Dorsum conspicuously papillated, particularly evident at mid-dorsal line 26*
25Dorsum with a vague, dark median stripe:
With two paramedial pairs of yellowish metameric spots; venter not striped; commonly encountered on mating amphibians in early spring, in woods ponds of northern United States and Canada
Placobdella picta (Verrill, 1872), n comb
- Dorsum lacking dark median stripe:
Venter with 8-12 bluish-green longitudinal stripes; dorsal pigmentation variable; typically encountered on turtles but often free-living
Placobdella parasitica (Say, 1824)
26Dorsum rough, entirely covered with numerous papillae, usually varying in size or randomly arranged:
Dorsum usually with a brown band at mid-dorsal line, interrupted 4-5 times; venter unstriped, with scattered dark chromatophores or plain; typical of the northern United States and Canada
Placobdella ornata (Verrill, 1872)
-Dorsum less rough, not entirely covered with papillae; larger papillae in 5-7 longitudinal rows 27*
27Venter with about eight bluish longitudinal stripes;
Body ovate-lanceolate; dorsum with a vague, median, longitudinal stripe, contained in a wider bluish stripe; the two pairs of salivary glands enter base of proboscis independently; widely distributed (Davies and Wilkialis 1980; Sawyer and Shelley 1976).
Placobdella papillifera (Verrill, 1872)
- Venter plain or with fine black chromatophores:
Body lanceoloate; typically with narrow dark mid-dorsal stripe which is usually continuous; the two pairs of salivary glands enter base of proboscis via a common duct; typically found in southeastern United States, where it replaces P ornata: sometimes parasitic on alligators (Forrester and Sawyer 1974)
Placobdella multilineata Moore, 1953