University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 1967 Freshwater snails of the family Lymnaeidae (Mollusca: Basommatophora) from western Montana Richard H. Russell The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation Russell, Richard H., "Freshwater snails of the family Lymnaeidae (Mollusca: Basommatophora) from western Montana" (1967). Graduate Student Theses, Dissertations, & Professional Papers. 6739. https://scholarworks.umt.edu/etd/6739 This Thesis is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. freshwater SNA IIS OF THE FAI4ILY LYMNAEIDAE (MOLLUSCAs BASOMMATOPHOEA) FROM WESTERN MONTANA by Richard H* Russell Be Ae University of Montana, 19^5 Presented in partial fulfillment of the requirements for the degree of Master of Arts UNIVERSITY OF MONTANA 1967 Approved by; Chal^pan, Board of Examiners Deany^Graduate School MAY 0 1 1.367 Date Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: EP37540 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMT DiiaafWiwi PubliaMn^ UMI EP37540 Published by ProQuest LLC (2013). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 10 6 -1 3 4 6 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS Page Lxsii/ o f m a p s #oo#eo*ooo*ooo@e*»o*e X i i. TjX s ij o f "pTsit esooooofio xv Tzi t z? 0(3,no t X o n * ZL Description of study area oo«ooo<,ooa*.co* 5 Materials and methods 7 Aolcno'w le dg e m e n t s ooa««oooot>ooDoo9 ooo ^ The family Lymnaeidae 0 0 0 0 0 , 0, 0 0 0 0 0 0 , * 10 lii S t o f s p e c i e s o«ooooooooooooooooo 11 ÎCey t o S p e O l O o OOOCOOOOOOOOOOOOOOOO 1 2 Systematic treatment O e n u s L y ^ ^ ^ ^ e a ** oo*,*,,,***,***,,* 13 OeTlUS Bad oooeoooooocooooo*o*, 21 Genus S ra gninola ooooooooooooooooo 2 6 vjrdXUiO J? Ç» ^ t -Lfj. OOOOOOOOOOOOOOOOOO J) Su.întïiary ,000,0000000 o , , o * , , » * , * 66 A p p e n d i c e s A, Distributional data, 0 0 , 0 0 0 0 0 0 0 0 0 , 67 Bo Species studied from adjacent areas, <» » , , , 89 Co The family Lancldae, o,*,,,,,,*,,, 93 M a p s 0000000000, 0000,000000000 93 P la te s , o o o 00 o o o o 00 , O O O </ O O o O , O O 1 X. 9 Literature cited oooo,oooo,,ooo,,o,o 1 3 3 11 ' Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF MAPS Page 1. Major watersheds of western Montana 96 2, Probable extent of Cordllleran Ice Sheet In western Montana 98 3e Counties in western Montana 100 4. Distribution of Lymnaea and in western Montana 102 5 • World-wide distribution of atagnails 104 6, World-Wide distribution of aurinul aria 106 7. Distribution of L.tagnLc-oLa in western Montana 108 8. Distribution of forms of Stagnicola in western Montana 110 9. Distribution of Stagnicola. subgenus Hinkloyia in western Montana 112 1 0 , Distribution of Possaria in western Montana 114 1 1 . Distribution of Fossarda in western Montana 116 12. Distribution of Fossarla parnra and £. in western Montana 118 111 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OP PLATES Page I. Lynmaeid shell and genitalia 120 II» Radulae of Lymnaeidae 122 IIIo Shells of Lymnaea etagn.alle and Radix 124 rVe Shells of Stagnicola 126 Vo Shells of Stagnicola 128 VIo Shells of Stagnloala. subgenus5inkleyla, and P os,s aria 131 VII• Shells of Fossanla and Lynmaeidae from areas adjacent to western Montana 134 iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. INTRODUCTION This study was undertaken for two reasons : (l) to survey the species of the family Lymnaeidae in Montana west of the Continental Divide ; and (2 ) to construct keys for the identifications of these species» As a result of this study, distributional data were collected for much of western Mon­ tana® My interest in this problem stems from ten years of collecting land and fresh-water mollusoa in Montana and of becoming aware of many of the difficulties encountered in separating genera and species® Very little has been published on any molluscan group in western Montana® The records for the Lymnaeidae are sporadic® Six new species or subspecies have been described from western Montana, and for most of these the only records are the original descriptions » The family Lymnaeidae is a world-wide group of fresh­ water snails, important as intermediate hosts for a large number of parasitic worms, particularly those of the family Fasciolidae® The anatomical similarity among species with­ in the family as a whole and the variation within any single population of one species create a number of unusual t-axo- nomic problems® The first work of any consequence on the family Lymnae­ idae in North America was written by W® G® Binney in his Land .ansi Enenh-Mater Bhells af. North America (I865)® Numerous Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. '2- authors since then have added to our knowledge of this group in North America» Probably the most significant contributions have been made by Frank Collins Baker. Baker spent many years describing the fresh water mol­ luscan faunas of this continent, and his works of 1911 and 1928 are regarded as basic to the study of the Lymnaeidae of North America. Baker considered the Lymnaeidae to consist of several genera and a large number of species. However, Colton (1914) questioned the generic groupings in Baker®s 1911 monograph, and suggested that the generic names used by Baker be used as subgenera within the single genus .Lynmaeao Baker published many anatomical drawings and radular formulae, giving one the impression of a very precise taxo­ nomic system within American lymnaeids. However, several works (see below) since Baker have shown that much of his data is incorrect. Most of his anatomical drawings are mis­ leading. Eadular formulae are never as consistent as Baker descriptions would lead one to believe. Hubendiok (1 9 5 1 ) revised the Lymnaeidae of the world based primarily on the shell and on a few characteristics of the genitalia. As a result of a careful biometric analysis of several populations of the complex species-group Radix peregra (L.) in western Europe, Hubendlck came to the con­ clusion that many of the specific names in the Lymnaeidae Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. “3" referred to eoological variants of but a few specieso As a result, be reduced nearly 1800 specific names to approxi­ mately 40, and included all but a few of the world Lymnae­ idae in the one genus Lyjmmsa.» Walter (1961) thoroughly studied the anatomy of one species of lyranaeid snail, Siagnlcola ama-pginata serrata (Haldeman), in an attempt to determine which anatomical features would best serve as taxonomic criteria. As a re­ sult of his investigations, he rejected the thesis of P. C . Baker, Hubendiok, and others, that the only anatomical structures of taxonomic significance are found in the distal part of the male genitalia. Particularly, he noted the taxonomic value of certain parts of the female genitalia. His findings indicate that, for the most part, the generic groupings used by Baker are valid» Both Hubendlck and Walter, from somewhat different points of view, seem to think that the most reliable taxo­ nomic characters are to be found in the shell.s. In addition to anatomy, other characteristics have been used in the taxonomy of the family Lymnaeidae. Wright 11939/ incorporated paper chromatography of fluorescent substances in the body-surface mucous in his studles. Burch (196Oa, b), in his studies of the chromosomes of aquatic pulraonate snails, fo'und that chromosome numbers and the nature of mitotic figures can be useful in clarifying systematic relationships Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. -4" within the Basommatophorao Bondeson (1 9 5 0 ) used the mor­ phology of the egg masses to show taxonomic differences among fresh-water snails, primarily on the familial and higher levels, but to a certain extent within genera and species. Recent American authors seem to favor recognition of several genera in the family Lytrmaeidaeo Taylor, Walter, and Burch (1 9 6 3 , p« 239) stated : "The fact that varying degrees of re­ lationships within this group can be recognized, primarily on the basis of genitalia and radula, but to a certain extent from shell sculpture, size of nuclear whorls, and other features, is a weighty objection to including all species in the one genus Lymnaea «" The generic separations used here are those used by Baker (1928)0 The same divisions are used by Zilch (1959- 6 0 ), and are recognized by most recent workers In this country» Reproduced with permission of the copyright owner.