Bivalve Molluscs Biology, Ecology and Culture Bivalve Molluscs Biology, Ecology and Culture Elizabeth Gosling Fishing News Books An imprint of Blackwell Science © 2003 by Fishing News Books, a division of Blackwell Publishing Editorial offices: Blackwell Publishing Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK Tel: +44 (0)1865 776868 Blackwell Publishing, Inc., 350 Main Street, Malden, MA 02148-5020, USA Tel: +1 781 388 8250 Blackwell Science Asia Pty, 550 Swanston Street, Carlton,Victoria 3053, Australia Tel: +61 (0)3 8359 1011 The right of the Author to be identified as the Author of this Work has been asserted in accordance with the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. First published 2003 Reprinted 2004 Library of Congress Cataloging-in-Publication Data Gosling, E.M. Bivalve molluscs / Elizabeth Gosling. p. cm. Includes bibliographical references. ISBN 0-85238-234-0 (alk. paper) 1. Bivalvia. I. Title. QL430.6 .G67 2002 594¢.4–dc21 2002010263 ISBN 0-85238-234-0 A catalogue record for this title is available from the British Library Set in 10.5/12pt Bembo by SNP Best-set Typesetter Ltd., Hong Kong Printed and bound in Great Britain by MPG Books Ltd, Bodmin, Cornwall The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. For further information on Blackwell Publishing, visit our website: www.blackwellpublishing.com Contents Preface ix Acknowledgements x 1 An Introduction to Bivalves 1 References 6 2 Morphology of Bivalves 7 Introduction 7 The shell 7 Mantle 19 Gills 23 The foot 26 Labial palps and alimentary canal 30 Gonads 34 Heart and haemolymph vessels 35 Excretory organs 37 Nerves and sensory receptors 37 References 39 3 Ecology of Bivalves 44 Introduction 44 Global and local distribution patterns 44 Factors affecting distribution and abundance 55 References 78 4How Bivalves Feed 87 Introduction 87 Filtration rate 87 Particle processing on the gills 97 Labial palps and pseudofaeces production and transport 102 Ingestion volume regulation 109 Pre-ingestive particle selection 110 The alimentary canal and digestive process 114 Food 118 Absorption efficiency 122 References 123 5 Reproduction, Settlement and Recruitment 131 Introduction 131 Differentiation of sexes 131 Gametogenesis 132 Reproductive cycles 133 v vi Contents Factors controlling reproduction 140 Annual storage cycle 145 Reproductive effort and fecundity 146 Deleterious effects on the reproductive cycle 149 Fertilisation 150 Larval development 151 Factors affecting larval growth 153 Larval dispersal 155 Settlement and metamorphosis 156 References 161 6Bivalve Growth 169 Introduction 169 Methods of measuring absolute growth 169 Allometric growth 176 Growth curves 177 Scope for growth 179 Factors affecting growth 182 References 194 7 Circulation, Respiration, Excretion and Osmoregulation 201 Circulation 201 Respiration 205 Excretion and osmoregulation 216 References 219 8 Fisheries and Management of Natural Populations 225 Introduction 225 Population dynamics 225 Fisheries assessment and management 242 Scallop fisheries 245 Oyster fisheries 253 Mussel fisheries 260 Clam fisheries 272 References 278 9Bivalve Culture 284 Introduction 284 Fundamentals of bivalve culture 285 Mussel culture 296 Oyster culture 304 Scallop culture 310 Clam culture 317 Bivalve culture and environment 325 References 327 10 Genetics in Aquaculture 333 Introduction 333 Contents vii Quantitative genetics 333 Selective breeding 334 Protein and DNA markers 345 Chromosomal genetics and ploidy manipulation 352 Benefits of ploidy manipulation 354 Transgenics 360 References 361 11 Diseases and Parasites 370 Introduction 370 Viruses 370 Bacteria 370 Fungi 373 Protozoa 374 Porifera 387 Helminths 387 Annelids 391 Crustaceans 391 Neoplasia 394 Defence mechanisms 395 Further research 400 References 401 12 Public Health 412 Introduction 412 Bacterial infections 412 Viral infections 413 Biotoxins 414 Industrial pollutants 420 Decontamination procedures 420 Monitoring and quality control 423 The HAACP system 425 References 427 Subject Index 432 Species Index 439 Preface The phylum Mollusca is one of the largest, most diverse and important groups in the animal kingdom. There are over 50 000 described species and about 30 000 of these are found in the sea. The class Bivalvia is one of six classes of molluscs and comprises animals enclosed in two shell valves. Examples are mussels, oysters, scallops and clams. Although the class contains a relatively small number of species, about 7500, it elicits substantial interest chiefly because so many of its members are eaten by people in large amounts. In 1999, production of bivalves from fisheries and aquaculture was over 10.6 million metric tonnes worldwide with a monetary value of over $9.3 billion (FAO, 2001). Some years ago while teaching a course on Bivalve Biology to aquaculture students I realized that although the students could access information from several texts, a single book covering all aspects of the biology, ecology and culture of bivalve molluscs did not exist. Thus the idea to write such a book was conceived. What started off as a small undertaking very quickly snow- balled into a substantial task, which took several years to complete, primarily due to my having to read and digest the wealth of published information. The focus of the book is on marine bivalves of commercial importance and it has been written primarily for undergraduate students. However, the book with its 1200 references will serve also as a useful starting point for postgraduate students and professionals working on reproductive physiology, ecology, genetics, disease, public health, aquaculture, and fisheries management of commercial bivalves. Chapter 1 is a brief introduction to the class Bivalvia, and describes the evolution of the group from a creeping ancestral mollusc to the burrowers and attached surface dwellers of today. Chapter 2 provides a detailed descrip- tion of external and internal anatomy, while Chapter 3 describes global and local distribution patterns, and the physical and biological factors influencing distribution and abundance. Filter feeding and controlling factors are covered in Chapter 4. Chapter 5 deals with reproduction, larval development and settlement, while Chapter 6 covers methods of measuring growth, and the various factors influencing growth. The processes of circulation, respiration, excretion and osmoregulation are described in Chapter 7. The fishery assess- ment and management methods that are used in commercial fisheries of mussels, oysters, scallops and clams are covered in Chapter 8. The fundamen- tals of bivalve aquaculture, and the application of genetic methods are treated in Chapters 9 and 10, respectively. Chapter 11 deals with diseases and para- sites, and the diversity of defense mechanisms utilized by bivalves. Finally, Chapter 12 deals with the role of bivalves in disease transmission to humans. ix Acknowledgements I would like to express my gratitude to the many colleagues and friends who have helped and given advice during the preparation of this book. In par- ticular I wish to thank my partner Jim, and son Daniel, for their continual support and patience. My sincere thanks to the following people who gener- ously took time to review chapters, or parts of chapters:Andy Beaumont, Peter Beninger, Andy Brand, Norbert Dankers, Antonio Figueras, Susan Ford, Jim Gosling, Philippe Goulletquer, Pauline King, Per Kristensen, Dave McGrath, Mark Norman, Kevin O Kelly, Brian Ottway, Maarten Ruth, Matthias Seaman, Ray Seed, Sandra Shumway and James Weinberg. The following people gave invaluable advice and information, particularly for the Bivalve Culture, and Fisheries and Management chapters: Gavin Burnell, Ryan Carnegie, Jonathan Clarke, Noel Coleman, Eric Edwards, Luca Garibaldi, Ximing Guo, David Gwyther,Wolfgang Hagena, Marc Herlyn, Bob Hickman, Jaap Holstein, C. Barker Jørgensen, Yoshinobu Kosaka, Ian Laing, John Lucas, Clyde MacKenzie Jr., K.S. Naidu, John Nell, Maurizio Perotti, Bettina Reineking, David Roberts, Luisa Salaris, Aad Smaal, Sue Utting and J. Evan Ward. My gratitude to all those who supplied slides or artwork: Andy Beaumont, Peter Beninger, Susan Bower, Craig Burton, John Costello, Caroline Cusack, Per Dolmer, Antonio Figueras, Susan Ford, Philippe Goulletquer, Niall Herriott, Akira Komaru, Maria Lyons Alcantara, Dave McGrath, Paul Moran, Kevin O Kelly, Brian Ottway, Christine Paillard, Linda Park, Chris Richardson, Maarten Ruth, Ray Seed, Gudrun Thorarinsdóttir, Michelle (Paraso) Tomlinson, James Weinberg and Michael Wilkins. To my colleagues in the School of Science, Galway–Mayo Institute of Technology for their steadfast support: Patricia Dineen, Imelda Divelly- McCann, Pauline King, Kathleen Lough, Declan Maher, Dave McGrath, Íde Ní Fhaolain, Brian Ottway, Colin Pybus, Gerry Quinn and Malachy Thompson. A very special thanks to my office mate, Miriam Pybus, who saw this book from conception to delivery. Thanks also to the