Hydrobioid gastropods of the western United States Robert

Hydrobioid gastropods of the western United States Robert Hershler Dept. of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, D. C. 20013 -7012 Phone (202) 633 -1747 Email hershlerr@si. edu

Outline of presentation • Introduction – relevant background information (scope, systematics, methods) • Work through a newly prepared taxonomic key to the hydrobioid genera of the western USA (including treatment of the NZMS) • Briefly review each genus

Geographic and taxonomic scope • Restricted to the portion of the United States that is west of the continental divide • Restricted to the family Hydrobiidae as traditionally constituted • Only formally described and currently recognized species are considered WA MT OR ID UT WY CO NV CA AZ NM

Diversity of the western hydrobioid fauna (number of western species in parentheses) Amnicola (1) Colligyrus (3) Eremopyrgus (1) Fluminicola (24) Ipnobius (1) *Littoridinops (1) *Potamopyrgus (1) Pristinicola (1) Pyrgulopsis (112) Taylorconcha (2) Tryonia (13) Total: 11 genera, 160 species (158 native) * Introduced to western United States

• Several traditionally recognized hydrobiid subfamilies are now treated as separate family units (Bouchet & Rocroi, 2005) based on molecular phylogenetic evidence (Wilke et al. , 2000, 2001) • The term “hydrobioid” (sensu Davis, 1979) is used for this taxonomic assemblage Hydrobiidae Hydrobiid systematics Moitessieridae Lithoglyphidae Cochliopidae Amnicolidae COI-18 S tree (Wilke et al. , 2001)

Classification of the western hydrobioid genera Family Amnicolidae Amnicola Colligyrus Family Cochliopidae Eremopyrgus Ipnobius Littoridinops Tryonia Family Hydrobiidae Pyrgulopsis Family Lithoglyphidae Fluminicola Family incertae sedis Potamopyrgus Pristinicola Taylorconcha

Early stage of taxonomic refinement • Most species recently described and little studied • Actual species diversity likely to be much larger than currently recognized • Generic classification has been in flux for the past few decades and is still somewhat unsettled

Construction of taxonomic key • Cannot construct key solely based on shells because western hydrobioid genera are principally differentiated by anatomical characters • To aid user, key only employs characters that can be readily observed using a dissecting microscope (i. e. , no detailed dissections of micro-anatomy, no need to use SEM) • Several genera and several characters appear twice in the key (consequence of variation within genera) • Key works best if multiple specimens are in hand

Methods • Relax snails with menthol prior to fixation (preferred) or simply place them into concentrated ethanol • Clean shells with Clorox; remove shell (from animal) with concentrated hydrochloric acid • Dissection tools – fine forceps, iridectomy scissors, insect pins

Examination of relevant male anatomy • Cut through or pull back mantle edge to expose entire penis • Examine both upper (dorsal) and lower (sides) of penis for glands

Examination of relevant female anatomy (oviduct glands) Ag • Oviduct glands (albumen gland, Ag; capsule gland, Cg) easily observed; remove digestive gland ovary (spire) if necessary Cg

Examination of relevant female anatomy (bursa copulatrix) bursa copulatrix Cg • Ag Cut along left side of mantle, pull tissue back (and remove stomach) to expose (left side of) oviduct glands and bursa copulatrix

1. Female oviduct glands well-developed. ………… 2 Oviduct glands atrophied (functioning as brood chamber) ………………. . ……………… 8

2. Penis simple ……………………………… 3 Penis having lobes and/or glands ………………… 6

3. Bursa copulatrix absent ………………Taylorconcha Bursa copulatrix present ……………………. . 4 seminal receptacle bursa copulatrix

Taylorconcha Hershler et al. , 1994 • Two species • Shell 2 -4 mm tall; globose to ovateconic • Middle-lower Snake River basin; rivers and their tributary springs

Taylorconcha • Penis vermiform; animal often very pale

4. Bursa copulatrix (and its duct) overlapping right side of albumen gland. . . Fluminicola Bursa copulatrix (and its duct) overlapping left side of albumen gland ……………………………. . 5 albumen gland bursa copulatrix bursal duct bursa copulatrix

4. Shell protoconch having spirally arranged sculpture. . . . . Fluminicola Protoconch surface wrinkled or pitted ……………. 5

Fluminicola Carpenter, 1864 • 24 species • Shell 2 -12 mm tall; globose to narrow conic • Northwestern USA (and western Canada); springs, streams, rivers, lakes

Tip of the iceberg? • 13 of 24 congeners recently described from upper Sacramento River basin (Hershler et al. , 2007) • Combined morphologymolecular approach was needed to delineate species • Results suggest that other Pacific Northwest drainages may also harbor a large number of undescribed species of Fluminicola

Fluminicola non-monophyly? • Fluminicola virens is strongly divergent (morphologically and genetically) relative to other congeners; genus is probably non-monophyletic • The resulting taxonomic problem is unresolved because the type species of Fluminicola (F. nuttallianus) is little studied and probably extinct F. nuttallianus F. virens

5. Penis rectangular to elongate (<4 X longer than wide). . . . Pyrgulopsis (in part) Penis vermiform (>6 X longer than wide). . . . . . Pristinicola

5. Penial duct narrow. . . Pyrgulopsis (in part) Penial duct wide. . . . . Pristinicola penial duct

5. Operculum thin, amber-colored. . . Pyrgulopsis (in part) Operculum thick, red. . . ……………. Pristinicola

Pristinicola Hershler et al. , 1994 • Monotypic (P. hemphilli) • Shell ca. 1. 5 -3. 5 mm tall; pupoidal • Lower Snake-Columbia River basin, northwest Great Basin, Pacific Coastal drainage in Washington; springs

6. Penis having surficial glands ……. . …… Pyrgulopsis (in part) Penis having papillae …………………. . . . Littoridinops Penis having an internal, tubular gland. …………… 7 papillae glandular field glandular pad tubular gland

Pyrgulopsis Call & Pilsbry, 1886 • 112 western species • Shell 1 -8 mm tall; globose to turriform • Widely distributed in western USA; springs, rivers, lakes • Many additional congeners await description

Another taxonomically challenging genus • M 1 A M 1 B P. n. sp. 1 M 3 A M 4 B M 5 A M 5 C M 5 B M 3 D M 4 D M 3 C 59 M 4 A 100 M 3 B M 4 C M 10 A 91 M 11 A M 16 A M 18 A 57 M 12 A M 12 B M 13 B 66 M 15 A M 13 D M 13 F M 14 B M 13 E M 13 C M 17 A M 22 A M 27 A M 28 A 92 M 24 B M 24 A P. turbatrix 57 M 19 A M 20 A 72 M 21 A M 30 A P. amargosae 100 62 100 NDI tree (Liu et al. , 2003) Mt. DNA phylogeny (to left) suggests that morphologically similar populations assigned to P. micrococcus represent multiple evolutionary lineages (indicated by arrows) and species requires revision 100 56 63 99 55 0. 005 substitutions/site P. isolata P. nanus P. owensensis P. perturbata P. giulianii P. stearnsiana - PC P. stearnsiana - CC P. stearnsiana - WC P. wongi P. californiensis P. sterilis P. greggi M 2 A 97 M 2 B M 2 C M 2 D 86 M 25 A 65 M 25 C M 26 A 96 M 26 C M 26 B P. n. sp. 2 P. deaconi P. fausta P. crystalis P. erythropoma Marstonia

Unsettled generic limits • Eastern North American COI tree genus Floridobia nested (Liu & within Pyrgulopsis clade Hershler, • Genera are morphologically similar but 2005) differ in number of Pyrgulopsis seminal receptacles (Sr) Pyrgulopsis Floridobia clade Sr Sr 84 0. 1 cruciglans kolobensis 81 variegata bryantwalkeri pictilis inopinata plicata lentiglans sterilis 96 Nymphophilus minckleyi Nymphophilus acarinatus manantiali pecosensis carinifera avernalis merriami bruneauensis sublata gibba 97 lata breviloba wongi greggi hubbsi 98 Floridobia floridana Floridobia winkleyi eremica 93 lockensis villacampae thermalis saxatilis peculiaris sadai davisi gilae deaconi militaris ventricosa 84 sulcata 61 neritella landyei trivialis arizonae archimedis bernardina 75 erythropoma fairbanksensis turbatrix 77 diablensis giulianii stearnsiana 81 taylori owensensis californiensis montana 63 anatina pellita bifurcata micrococcus dixensis conica simplex glandulosa sola 91 robusta 2 74 intermedia 97 Marstonia halcyon 100 Marstonia agarhecta Marstonia hershleri Cincinnatia integra Floridobia

Littoridinops Pilsbry, 1952 • One western species (L. monroensis), introduced; native to Atlantic coast of USA • Shell up to 4. 7 mm tall; conical • San Francisco Bay; estuaries

7. Shell 3. 0 -4. 5 mm tall …………. . . . . Amnicola Shell 1. 3 -3. 3 mm tall ……. . . …. …. . . Colligyrus 1 mm

7. Penial lobe medially positioned ……. . . . . Amnicola Penial lobe basally positioned …………… Colligyrus penial lobe

Amnicola Gould & Haldeman, 1840 • One western species (A. limosus) • Shell 3. 0 -4. 5 mm tall, sub-globose to ovateconic • Northeast Great Basin, upper Columbia River basin (also widespread in eastern USA); lakes

Colligyrus Hershler et al. , 1999 • Three species • Shell 1. 3 -3. 3 mm tall, globose to conical • Northeastern and northwestern Great Basin, upper Snake and upper Sacramento River basins; springs

8. Males absent ……………………. . . 9 Males present …………………………. . 10 9. Shell conical; outer lip of aperture thickened internally …. . . . Potamopyrgus Shell turriform; outer lip of aperture thin or only slightly thickened. . . . . Tryonia (in part)

9. Inner side of operculum having a white (calcareous) smear …. . . Potamopyrgus Inner side of operculum without a white (calcareous) smear. . . Tryonia (in part)

Potamopyrgus Stimpson, 1865 • One western species (P. antipodarum), introduced; native to New Zealand • Shell up to 5 mm tall; conical • Widely distributed in Snake-Columbia River basin, eastern Great basin; scattered occurrences in other western drainages; diverse habitats

10. Penis without lobes ………. . . . Potamopyrgus Penis having lobe(s) ……………………. 11 penial lobe

11. Penial lobes cuboidal. . . . Eremopyrgus Penis having papilla(e) ……………………. . . 12

Eremopyrgus Hershler et al. , 1999 • One western species (E. eganensis) • Shell 3. 1 -3. 8 mm tall; conical • North-central Great Basin (Steptoe Valley); springs

12. Single papilla present on penis. . ……………. . . . Ipnobius Two to six papillae present on penis. . …. . Tryonia (in part)

Ipnobius Hershler, 2001 • Monotypic (I. robustus) • Shell 1. 1 -2. 2 mm tall, ovate-conic or conical • Southwestern Great Basin (Death Valley); thermal springs

Tryonia Stimpson, 1865 • 13 western species • Shell 1. 2 -7. 5 mm tall; ovate-conic to turriform • Widely (but disjunctly) distributed in southwest USA; typically found in thermal springs

Estuarine Tryonia • T. imitator; widespread (historically), native • T. porrecta (= T. protea); San Francisco Bay, cryptogenic