VARIABILITY IN SOUTH AMERICAN Psni (PmMoNAT., BAS0NMAT0PH0RA.) Mara L1cia Ferreira Dias Thesis presented for the, degree of Master of Philosophy University of Edinburgh 1984 B L. 0 In accordance with the regulations of the University of Edinburgh, I hereby declare that this thesis has been composed entirely by myself and that all the work described herein was carried out by myself alone, except where stated in the acknowledgements. This thesis is dedicated to my parents, my husband, and my son for all their love and encouragement. CONTENTS Page Number ACKNOWLEDGEMENTS ............................... vi ABSTRACT ....................................... X CHAPTER 1. INTRODUCTION........................ 1 1.1 Objectives ......................... 4 1.2 Literature review of Physidae supraspecific taxonomy ............ 5 1.3 Literature review of South American Physidae species 7 1.4 Summary of the present state of South American Physidae systematics., 19 CHAPTER 2. MATERIALS AND METHODS .............. 27 2.1 Samples of Physidae ............... 27 2.2 Shell measurements ................ 34 2.2.1 Fundamental orientation of the shell .................. 37 2.2.2 Characters definition 40 2.2.3 Discarded characters 52 2.3 Shell statistical analysis 54 2.3.1 Regression analysis 54 Page Number 2.3.2 Principal Component Analysis(PCA) ............. 56 2.4. Anatomical analysis ............... 57 2.4.1 Characters definition 67 2.4.2 Discarded characters 84 CHAPTER 3. INTRA AND INTERSPECIFIC VARIABILITY OF SHELL CHARACTERS IN STENOPHYSA AND PHYSELLA POPULATIONS ............ 86 3.1 Regression analysis ............... 86 3.2 Principal component analysis (PCA) 87 CHAPTER 4. INTRASPECIFIC VARIATION OF ANATOMICAL CHARACTERS IN STENOPHYSA AND PHYSELLA POPULATIONS ................163 4.1 Fundo Creek Stenophysa population 163 4.1.1 Variability ................163 4.1.2 Identification .............182 4.1.3 Assessment of characters 192 4.2 Idenfication and variability of other Stenophysa samples ..........197 4.3 Identification and variability of Physella samples ..................205 Page Number CHAPTER 5. GENERAL DISCUSSION AND CONCLUSIONS .......................... 220 CHAPTER 6. REFERENCES ........................ 238 vi.. ACKNOWLEDGEMENTS I express my sincere thanks to my supervisors Dr. Tom Warwick and Professor Aubrey Manning of the University of Edinburgh and Dr. Warton Monteiro of Universidade de Brasilia for giving me the opportunity to develop this thesis partially in Edinburgh, Scotland and partially in Brasilia, Brazil. For their criticism, guidance, encouragement, helpful discussions, and for providing facilities I am grateful too. To Dr. W. Monteiro my sincere thanks also for the special help with the syntax of this thesis, valuable criticism and suggestions on shell methodology, and for critically reading this manuscript during the preparation of this thesis. rnough his guidance, I have learned a lot, specially about scientific logic. I am deeply indebted to my husband, Dr. Braulio F. S. Dias, for giving me encouragement and support to study South American Physidae, for critically reading this manuscript, for helpful discussion on several topics of this work, specially shell statistical analysis, and also for his help to obtain several references. My sincere thanks to Dr. George A. Te of Ann Arbor, Michigan, U.S.A., for lending me representative shells of South American Physidae (Analogs), his Physidae manuscripts, several vii. transparencies of paratypes and holotypes, and, also for the discussion of some aspects of this project. I am much greateful to Dr. W. L. Paraense of Instituto Oswaldo Cruz, Rio de Janeiro, for the gift of preserved snails and empty shells of Physidae, collected by himself in different South American and West Indies Countries, and also for his help in obtaining references. My appreciation also to the following museum curators for giving me the opportunity to study their Physidae Collections: Dr. A. H. Clarke (National Museum of Natural History, Washington, U.S.A.); Dr. W. K. Emerson (American Museum of Natural History, New York, U.S.A.); Dr. J. B. Burch (Museum of Zoology, University of Michigan, Ann Arbor, U.S.A.); Dr. D. Heppel (Royal Scottish Museum, Edinburgh, Scotland); and Dr. L. P. Neme (Museu de Zoologia, Universidade de São Paulo, Sao Paulo, Brazil), with special thanks for lending the paratypes of Physa (Physella) papaveroi Leme (MZ 16618) and specimens of "Pysa (Physella) cubensis" sensu Leme (MZ 17997). I wish to thank Dr. Tom Warwick for helping to gather Physidae species from several places of Europe and for collecting some of them around Edinburgh. My sincere thanks to the following scientists for the obtainment of Physidae material: Dr. J. B. Burch, for several alcohol lots of North American viii Physidae; Dr. D. Heppel, for a shell of Stenophysa maugeriae and alcohol lots of Aplexa hypnorum; and to Dr. A. Norris, Department of Leisure Services, Leeds, England, for collecting Physella acuta from Leeds; Mrs. M. Fogan, Conchological Society of Great Britain and Ireland, Manchester, England, for collecting Physella gyrina from Chester, Liverpool, England; Dr. Shelagh Smith, Royal Scottish Museum, for collecting P. acuta from Hazeihead Park, Aberdeen, Scotland; Dr. Barry Colville, Leeds, for collecting A. hypnorurn from Leeds; Dr. Plummer, Royal Veterinary College, London, for collecting Physella acuta from Richmond Park, London, England; Dr. J. F. Vaz, from Superintend&ncia de Controle de Endemias (SUCEM), Säo Paulo City, for preserved material and shells of Stenophysa marmorata from So Paulo. State; Dr. W. Monteiro for collecting S. marmorata from the following Brazilian localities: Joo Pessoa, Paraiba State; Rio de Janeiro, Rio de Janeiro State; Corumb, Mato Grosso do Sul State; and Canabrava, Goiás; Dr. M. B. Monteiro of Universidade de Brasilia for S. marmorata specimens from Diamantina, Minas Gerais State; and Dr. B. F. Dias for S. marmorata from Belém, Pars State. I am indebted to Maria Cristina Pons da Silva and to Dr. Inga L. V. Mendes from the Museu de Cincias Naturais (MCN), Porto Alegre, Rio Grande do Sul, Brazil; Dr. Arnaldo C. dos Santos Coelho, Museu Nacional, ix Rio de Janeiro City; Dr. J. L. de Barros Araüjo from the Universidade Federal Rural do Rio de Janeiro, Itagual, Rio de Janeiro; Dr. L. P. Neme; Dr. D. Heppell; and, finally, to Mrs. Hext the librarian of Zoology Department, University of Edinburgh, for the obtainment of references. For their helpful discussion on topics of this work 'I am grateful to the molluscan specialists, Dr. G. M. Davis, from the Academy of Natural Sciences, Philadelphia, U.S.A.; Dr. D. Heppell; and Dr. J. L. M. Leme, Museu de Zoologia, Universidade de São Paulo, Sao Paulo City. My thanks also to Mrs. Maria Inez M. T. Walter and Mrs. Tnia Mara de A. Campos, Centro de Processamento de Dados (CPD - SAU), Universidade de Brasilia, for the help with computer analysis. Finally I would like to acknowledge the financial support of the Brazilian National Research Council (Conselho Nacional de Desenvolvimento Cientifico e Tecnolôgico - CNPq). x ABSTRACT The objectives of this study were to assess the intraspecific variability of shell and anatomical chracters used in Physidae systematics, determining the size independent ones, and to assess their taxonomical significance; to identify specimens from South America, specially Brazil, adding further distribution records, and evaluate the specific status of "Physa (Physella) papaveroi Leme, 1966", and "Physa (Physella) cubensis sensu Leme, 1966". Twenty one shell measurements of 158 specimens and 26 anatomical characters of 90 specimens were scored mainly in Stenophysa marmorata (Guilding, 1828) and Physella (Costatella) acuta (Draparnaud, 1805) from South and Central America, West Indies and Great Britain. A new conchometric method was developed and several characters redefined. Eight shell characters were found to be size independent. Regression coefficient tests were calculated for S. marmorata and P. acuta populations without any significant difference. Two shell ratios were constant within the size range of the analysed material, granting them taxonomical use. Bursa Copulatrix Axis, Digestive Tract Pigmentation, Shape of Gizzard, Preputial Gland Presence and Retractor Muscle were constant for S. marmorata, xi having generic diagnostic value. Tubular Nature of the Kidney, Penial Complex Type and Number of Segments in the Penial Sheath were constant for S. marmorata, having specific diagnostic value. Tendency of Preputial Gland to Flatten and Swelling of Penial Sheath Terminus were constant for P. acuta, having specific diagnostic value. The remaining anatomical characters were variable and of doubtful use for taxonomical purposes. States of Mantle Pigment Pattern and Mantle Lappet Type were redefined. Nineteen shell characters of S. marmorata and P. acuta from 39 localities were studied by Principal Component Analysis (PCA). The three Principal Components were 75% of the total variation in S. marmorata, 89% in P. acuta, and 74% in both . The first Principal Component (shell size) alone represented 53%, 58% and 51% of the total variation in S. marmorata, P. acuta, and both, respectively. The second and third Principal Components (angles) separated S. marmorata from P. acuta, and disclosed distinct clusters within each species. No anatomical difference was found between these clusters within each species, confirming the intraspecific nature of such clusters. This study discloses the first record of P. acuta (Draparnaud)