Frogs as Host-Parasite Systems I

Transcription

1 Frogs as Host-Parasite Systems I

2 Frogs as Host-Parasite Systems I An Introduction to Parasitology through the Parasites of Rana temporaria, R. esculenta and R. pipiens 1. D. Smyth* and M. M. Smyth * Department of Zoology and Applied Entomology Imperial College, Unirersity of London M

3 J. D. Smyth and M. M. Smyth 1980 Softcover reprint of the hardcover 1st edition All rights reserved. No part of this publication may be reproduced or transmitted, in any form or by any means, without permission First published 1980 by THE MACMILLAN PRESS LTD London and Basingstoke Associated companies in Delhi Dublin Hong Kong Johannesburg Lagos Melbourne New York Singapore and Tokyo British Library Cataloguing in Publication Data Smyth, James Desmond Frogs as host-parasite systems Parasites-Frogs I. Title II. Smyth, M M 597'.8 SF997.5.F/ ISBN ISBN (ebook) DOI / This book is sold subject to the standard conditions of the Net Book Agreement The paperback edition of this book is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, reso~.. hired out, or otherwise circulated without the publisher s prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser

4 Contents Introduction and Aims Acknowledgements Part I Frog Parasites and their Biology I. Examination for parasites: basic procedures 1.1 Frogs as hosts 1.2 Preparation of frogs for dissection 1.3 Preparation for parasite collection 1.4 Summary of practical procedures 1.5 External examination: skin and associated cavities 1.6 Internal examination 2. Protozoa 2.1 Examination of living protozoa 2.2 Making rapid, stained 'smears' of protozoa vii IX I I Protozoa in the alimentary canal Protozoa in the kidney Protozoa in the blood 14 Trematoda Note on procedure Commonly occurring trematodes Examination of living trematodes Monogenea Digenea: Identification Digenea: Paramphistomidae Digenea: Gorgoderidae Digenea: Lecithodendriidae Digenea: Hemiuridae Digenea: Cephalogonimidae Digenea: Plagiorchiidae 42 Cestoda Identification of adult cestodes 56 v

5 VI CONTENTS 4.2 Adult cestodes III R. temporaria and R. esculenta 4.3 Adult cestodes in R. pipiens 4.4 Larval cestodes 5. Nematoda Examination of nematodes Identification of nematodes Order: Rhabditida Order: Strongylida Order: Oxyurida/Ascaridada Order: Spirurida Acanthocephala The ecology of Rana species in relation to their parasite fauna Basic ecology of Rana temporaria Basic ecology of Rana esculenta Basic ecology of Rana pipiens Ecological factors and the parasite fauna of R. temporaria and R. esculenta Ecological factors and the parasite fauna of R. pipiens 80 Part 2 Techniques and Experimental Methods 8. Experimental methods: Protozoa 8.1 Fixation and staining 8.2 In vitro culture 8.3 Trypanosomes: the haematocrit centrifuge technique (of Woo) for examining small quantities of blood Staining blood films Opalinids and ciliates: induction of sexual reproduction Experimental methods: Trematodes Cercariae release and encystment Demonstration of argentophilic 'papillae' in cerariae ( = chetotaxie) Egg embryonation and hatching of trematode eggs Demonstration of the nervous system in trematodes by the indoxyl acetate method for esterase (e.g. cholinesterase) Demonstration of egg-shell precursors in trematodes In vitro culture of lung flukes and lung tissues 93 References 95 Index 102

6 Introduction and Aims The aim of this book is to introduce students to parasitology, using the frog and its parasites as a model hostparasite system. Classes in zoology and vertebrate physiology have long used a frog as a basic animal type and its anatomy and physiology have been thoroughly studied; yet its contained parasites are often overlooked and students are generally unaware of the additional wealth of biological material available. Parasitology is a complex discipline with ramifications into many other biological fields. The study of a single hostparasite system such as the frog, with its rich fauna of parasites, can, however, introduce students to many of its branches-taxonomy, morphology, cytology, physiology and ecology. Furthermore, amphibian parasites often serve as superb experimental material, providing the student with an introduction to some basic techniques in cell biology and physiology, as well as to the principles of experimental parasitology. This text deals primarily with the parasites of the three species of frog commonly used in biological laboratories in Europe and North America-Rana temporaria, R. esculenta and R. pipiens. It is not our intention to deal with all the parasites recorded from these hosts, but to provide basic data, and a comprehensive bibliography, on those protozoan and helminth species most likely to be routinely encountered; arthropod parasites (which are rare) are briefly mentioned. Data on frog parasites are scattered in numerous journals and to our knowledge have not previously been brought together in one volume. Some valuable surveys of frog parasites have been made by Combes 19, COX 22, Lees 91, Mazurmovich 104, Reichenbach-Klinke and Elkan 145, Vojtkova 174, 177, 182 and Walton l85, 186. A comparable volume on the parasites of the African toad, Xenopus laevis, is in preparation 166. APPROACH The first part of this book deals with the examination of a Vll

7 viii INTRODUCTION AND AIMS frog for parasites. Data are given on the morphology, taxonomy and life cycles of the commoner species, and simplified keys are provided where relevant. Rarer species, or those not commonly encountered, are not described in detail but are included in the tables. The ecology of the frog and its relationship with that of the parasitic fauna are discussed where appropriate. The second part provides procedures for simple experiments, such as: life cycle studies; egg and cyst hatching; in vitro culture; cytology and histochemical tests; parasite differentiation and development. Although this volume deals with R. temporaria, R. esculenta and R. pipiens, the principles and techniques involved are readily adaptable to other amphibian species. It is hoped that workers in different countries will continue to examine their local species and record the parasites found; this additional data could make a valuable contribution to teaching and research in parasitology. Most of the techniques and procedures described here can readily be carried out in laboratories where only the simplest equipment is available. It is assumed that the student is familiar with the general anatomy and dissection of a frog as this has not been dealt with in detail here. F or details of practical proced ures for the main tenance of living frogs in the laboratory, the following should be consulted: Bardsley and Harmsen 5, Von Filek 42 and Naceet al. 122 London, 1980 J.D.S. M.M.S.

8 Acknowledgements Our special thanks are due to Miss Sue Venner for her meticulous preparation of a number of the illustrations, particularly the life cycle drawings; and to Mrs. Gwen Adams for her generous help, especially in typing the manuscript. Most of the illustrations of organisms have been redrawn from original sources to conform to a uniform style; acknowledgement is made to the authors in legends. We are indebted to the publishers and editors of the journals, listed below, for permlsslon to use illustrations: Acta Parasit%gica P%nica; Acta Tropica; American Mid/and Naturalist; Angewandte Parasit%gie; Anna/es de Parasitologie Humaine et Comparee; Appleton-Century-Crofts, Inc. N.Y.; Archiv fur Protistenkunde; Archives de l'institut Pasteur du Maroc; Bulletin de I'Academie Polonaise des Sciences, Serie des Science Biologiques; Bulletin de la Societe Neuchateloise des Sciences Naturelles; Bulletin of the University of Nebraska State Museum; Cambridge University Press; Canadian Journal of Zoology; Folia Facultatis Scientiarum Naturalium Universitatis Purkynianae Brunensis; International Journal for Parasitology; Journal of Morphology; Journal of Parasitology; Keigaku Publishing Co., Japan; McGraw-Hill Book Co. Inc.; Memoires du Museum National d'histoire Naturelle, Paris; Parasitology; Parasitologiya; Proceedings of the Helminth%gical Society of Washington; Protistologica; Revue Suisse de Zo%gie; Scripta Facultatis Scientiarum Naturalium Universitatis Purkynianae Brunensis; Charles C. Thomas, Springfield, Illinois, U.S.A.; Transactions of the American Microscopical Society; University Park Press, "Baltimore, Maryland, U.S.A.; nstnik teskoslovenske Spole'tnosti Zoologicke; Zeitschrift fur Parasitenkunde. ix