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Hydrobioid gastropods of the western United States

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.

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Hydrobioid gastropods of the western United States

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  1. 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

  2. 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

  3. Geographic and taxonomic scope WA MT OR • 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 ID WY UT CO NV CA AZ NM

  4. 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

  5. Hydrobiid systematics • 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 Moitessieridae Lithoglyphidae Cochliopidae Amnicolidae COI-18S tree (Wilke et al., 2001)

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

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

  12. 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

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

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

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

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

  17. Taylorconcha • Penis vermiform; animal often very pale

  18. 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 bursal duct albumen gland bursa copulatrix bursa copulatrix

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

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

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

  22. 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

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

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

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

  26. 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

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

  28. 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

  29. Another taxonomically challenging genus 100 M1A 56 M1B P. n. sp. 1 M3A M4B M5A M5C M5B M3D M4D M3C 59 M4A 100 NDI tree (Liu et al., 2003) M3B M4C M10A 91 M11A M16A M18A 57 M12A M12B M13B 66 M15A M13D • MtDNA phylogeny (to left) suggests that morphologically similar populations assigned to P. micrococcus represent multiple evolutionary lineages (indicated by arrows) and species requires revision M13F M14B M13E M13C M17A M22A M27A M28A 92 M24B M24A P. turbatrix 57 M19A M20A 72 M21A M30A P. amargosae 100 P. crystalis 62 P. erythropoma 100 P. isolata P. nanus 100 P. owensensis P. perturbata 56 P. giulianii 63 P. stearnsiana - PC P. stearnsiana - CC P. stearnsiana - WC P. wongi P. californiensis P. sterilis P. greggi M2A 97 M2B M2C M2D 86 M25A 65 M25C 99 M26A 96 M26C M26B P. n. sp. 2 55 P. deaconi P. fausta Marstonia 0.005 substitutions/site

  30. Unsettled generic limits cruciglans kolobensis 81 variegata bryantwalkeri pictilis inopinata plicata lentiglans sterilis 96 Nymphophilusminckleyi COI tree (Liu & Hershler, 2005) Nymphophilus acarinatus manantiali pecosensis carinifera avernalis merriami bruneauensis • Eastern North American genus Floridobia nested within Pyrgulopsis clade • Genera are morphologically similar but differ in number of seminal receptacles (Sr) Floridobia sublata gibba 97 lata breviloba wongi greggi hubbsi 98 Floridobia floridana Floridobia winkleyi eremica 93 lockensis villacampae thermalis saxatilis peculiaris Pyrgulopsis clade sadai davisi gilae deaconi Pyrgulopsis Floridobia militaris ventricosa 84 sulcata 61 neritella landyei trivialis arizonae archimedis bernardina 75 erythropoma fairbanksensis turbatrix 77 diablensis giulianii stearnsiana 81 taylori owensensis californiensis 63 montana anatina pellita bifurcata micrococcus Sr dixensis conica simplex Sr 84 glandulosa sola 91 robusta1 robusta2 74 intermedia 97 Marstonia halcyon 100 Marstonia agarhecta Marstonia hershleri Cincinnatia integra 0.1

  31. 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

  32. 7. Shell 3.0-4.5 mm tall ……………………................... Amnicola Shell 1.3-3.3 mm tall …….........................….…... Colligyrus 1 mm 1 mm

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

  34. Amnicola Gould & Haldeman, 1840 • One western species (A. limosus) • Shell 3.0-4.5 mm tall, sub-globose to ovate-conic • Northeast Great Basin, upper Columbia River basin (also widespread in eastern USA); lakes

  35. 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

  36. 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)

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

  38. 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

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

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

  41. 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

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

  43. Ipnobius Hershler, 2001 • Monotypic (I. robustus) • Shell 1.1-2.2 mm tall, ovate-conic or conical • Southwestern Great Basin (Death Valley); thermal springs

  44. 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

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

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