THE BIOLOGY AND EVOLUTION OF TREMATODES AN ESSAY ON THE BIOLOGY, MORPHOLOGY, LIFE CYCLES, TRANSMISSIONS, AND EVOLUTION OF DIGENETIC TREMATODES THE BIOLOGY AND EVOLUTION OF TREMATODES An Essay on the Biology, Morphology, Life Cycles, Transmissions, and Evolution of Digenetic Trematodes by KIRILL V. GALAKTIONOV Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia and ANDREJ A. DOBROVOLSKIJ St. Petersburg State University, St. Petersburg, Russia Translated from Russian by NATALIE V. LENTSMAN, ALEXANDRA D. KHARAZOVA, VASILII E. STEFANOV and TATIANA A. GANF Edited by BERNARD FRIED and THADDEUS K. GRACZYK SPRINGER-SCIENCE+BUSINESS MEDIA, B.V. A C.I.P. Catalogue record for this book is available from the Library of Congress. ISBN 978-90-481-6430-1 ISBN 978-94-017-3247-5 (eBook) DOI 10.1007/978-94-017-3247-5 Printed on acid-free paper All Rights Reserved © 2003 Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 2003 Softcover reprint of the hardcover 1st edition 2003 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Table of Contents Preface...................................................................................................... ix Introduction.............................................................................................. xi Acknowledgements................................................................................ xix 1. Organization of parthenogenetic and hermaphroditic generations of tremtodes.................................................................................................. 1 1. Parthenogenetic generations and their larva.......................................... 1 1.1 First parthenogenetic generation.................................................. 2 1.2 The second (Daughter) parthenogenetic generation .................. 52 1.3 Organization of the generative apparatus and early stages of development of sporocysts and rediae........................................ 75 2. The hermaphroditic generation ........................................................... 93 2.1 Cercaria...................................................................................... 94 2.2 Metacercaria ............................................................................ 151 2.3 Marita (adult)........................................................................... 188 2. The trematode life cycle as a system of adaptations.......................... 215 1. Adaptations of the first parthenogenetic generation.......................... 216 1.1 Adaptations of miracidia.......................................................... 216 1.2 Adaptations of the m.other sporocyst ...................................... 244 2. Adaptations of daughter generations of parthenitae.......................... 253 2.1 Adaptations of daughter generations of parthenitae manifest at the individual level ............................................................... 253 2.2 Group Adaptations of daughter generations of parthenitae ..... 258 3. Hermaphroditic generation................................................................ 261 3.1 Adaptations of cercariae .......................................................... 261 3.2 Metacercaria ............................................................................ 304 3.3 Marita (Adult).......................................................................... 310 vi Table of Contents 3. The main types of trematode life cycles.............................................. 319 1. Trixenous (three-host) life cycles...................................................... 323 2. Trixenous (three-host) life cycles with two endogenous agglomerations ................................................................................. 332 3. Dixenous (two-host) life cycles......................................................... 334 3.1 Primary dixenous life cycles.................................................... 335 3.2 Secondary dixenous life cycles................................................ 338 4. Homoxenous (one-host) life cycles................................................... 344 5. Tetraxenous (four-host) life cycles.................................................... 346 4. Specific traits of populations formed by trematodes......................... 349 1. On the nature of trematode populations ............................................ 349 2. Host-parasite interactions and their manifestation on populational level.................................................................................................. 354 3. Phase analysis of trematode populations........................................... 360 3.1 Hemipopulations of mother sporocyst larvae .......................... 360 3.2 Hemipopulations (Infrapopulations) of parthenogenetic generations................................................................................ 365 3.3 Hemipopulations of cercariae.................................................. 384 3.4 Hemipopulations (Infrapopulations) of metacercariae ............ 399 3.5 Hemipopulations (infrapopulations) of maritae....................... 399 4. General notes..................................................................................... 402 5. The main trends in trematode evolution ............................................ 407 1. The main trends of morphological evolution of trematodes.............. 407 1.1 The parthenogenetic generations ............................................. 408 1.2 The hermaphroditic generation................................................ 434 2. Ways of biological radiation of trematodes into different ecosystems........................................................................................ 467 2.1 Ecological context of trematode life cycle formation.............. 469 2.2 Expansion into the ecosystems of pelagic zone....................... 471 2.3 Colonization of terrestrial and marine littoral ecosystems ...... 473 2.4 Patterns of strigeidida and plagiorchiida transmission ............ 477 2.5 Concluding Remarks ............................................................... 478 6. Evolution of life cycles and phylogeny of trematodes........................ 481 1. Origin and evolution of trematode life cycles ................................... 482 1.1 Approaches to the analysis of the nature and evolution of the trematode life cycles .............................................................. 482 1.2 Main stages in the evolution of trematode life cycles ............. 491 Table of Contents vii 2. The main trends in evolution of trematode life cycles ...................... 498 3. Possible approaches to establishing a natural classification of trematodes ........................................................................................ 506 References .................................................................................................. 529 Index........................................................................................................... 575 Preface The book by K.V. Galaktionov and A.A. Dobrovolskij maintains the tradi- tion of monographs devoted to detailed coverage of digenetic trmatodes in the tradition of B. Dawes (1946) and T.A. Ginetsinskaya (1968). In this re- spect, the book is traditional in both its form and content. In the beginning (Chapter 1), the authors provide a consistent analysis of the morphological features of all life cycle stages. Importantly, they present a detailed charac- terization of sporocysts and rediae whose morphological-functional organi- zation has never been comprehensively described in modern literature. The authors not only list morphological characteristics, but also analyze the functional significance of different morphological structures and hypothesize about their evolution. Special attention is given to specific features of mor- phogenesis in all stages of the trematode life cycle. On this basis, the authors provide several original suggestions about the possible origins of morpho- logical evolution of the parthenogenetic (asexual) and the hermaphroditic generations. This is followed by a detailed consideration of the various mor- phological-biological adaptations that ensure the successful completion of the complex life cycles of these parasites (Chapter 2). Life cycles inherent in different trematodes are subject to a special analysis (Chapter 3). The authors distinguish several basic types of life cycles and suggest an original interpretation of their evolutionary origin. Chapter 4 features the analysis of structure and the dynamics of trematode populations and is unusual for a monograph of this type. This chapter begins with a discussion of general issues, i.e., the nature of popula- tions of parasitic organisms and the patterns of interaction between hosts and parasites at the population level. This is followed by a detailed analysis of groups formed by free-living and parasitic stages of trematode life cycles in the environment or in the host. The two final chapters in the book are very important. In these chapters the factual material presented in the preceding four chapters is dis- cussed