Scallops (Hardcover, 2nd)

Table of Contents

Dedication?????????????? v Preface???????????? vii Preface from first edition????????????? ix List of contributors????????????? xi

Chapter 1. ?New Phylogenies of the Pectinidae (Mollusca: Bivalvia): Reconciling Morphological and Molecular Approaches Thomas R. Waller

1.1 Introduction?????????????? 1 1.1.1 Molecular genetic studies?????????????? 1 1.1.2 Methods and materials?????????????? 7 1.2 New observations???????????? 10 1.2.1 Subfamily Camptonectinae Habe, 1977???????????? 10 1.2.2 Subfamily Palliolinae Korobkov in Eberzin, 1960???????????? 10 1.2.2.1 Tribe Pseudentoliini, new tribe???????????? 12 1.2.2.2 Tribe Adamussiini Habe, 1977???????????? 13 1.2.2.3 Tribe Eburneopectinini, new tribe???????????? 14 1.2.2.4 Tribe Serripectinini, new tribe???????????? 15 1.2.2.5 Tribe Palliolini Korobkov in Eberzin, 1960???????????? 17 1.2.2.6 Tribe Mesopeplini, new tribe???????????? 20 1.2.3 Origins of the Decatopecten and Pecten Groups???????????? 22 1.2.4 Eastern Atlantic Pecten???????????? 28 1.3 Conclusions???????????? 30 Acknowledgments???????????? 32 References???????????? 32 Appendix???????????? 43

Chapter 2. ?Development, Physiology, Behaviour and Ecology of Scallop Larvae Simon M. Cragg

2.1 Introduction???????????? 45 2.2 Scallop life history characteristics???????????? 45 2.3 Larval development???????????? 55 2.3.1 Embryogenesis???????????? 55 2.3.2 Development of the larval shell???????????? 56 2.3.3 Organogenesis???????????? 59 2.3.3.1 Development of ciliation, the prototroch and the velum???????????? 59 2.3.3.2 Larval mantle???????????? 64 2.3.3.3 Musculature???????????? 64 2.3.3.4 Digestive tract???????????? 68 2.3.3.5 Sense organs???????????? 68 2.3.3.6 Apical organ???????????? 68 2.3.3.7 Statocysts???????????? 73 2.3.3.8 Eye spots???????????? 73 2.3.3.9 Mantle ciliation???????????? 74 2.3.3.10 Foot???????????? 77 2.3.3.11 Nervous system???????????? 78 2.3.3.12 Other organs???????????? 79 2.3.4 Metamorphosis???????????? 79 2.4 Comparative anatomy???????????? 81 2.5 Functional morphology???????????? 84 2.5.1 Locomotion???????????? 84 2.5.2 Feeding???????????? 85 2.5.3 Respiration???????????? 85 2.5.4 Sensory reception???????????? 86 2.6 Physiology and effects of environmental variables???????????? 87 2.6.1 Energy reserves and feeding???????????? 87 2.6.2 Respiration???????????? 88 2.6.3 Growth???????????? 89 2.6.4 Biochemical events during metamorphosis???????????? 90 2.7 Behaviour and larval distribution???????????? 90 2.7.1 Characteristics of locomotion during larval development???????????? 90 2.7.2 Responses to stimuli???????????? 91 2.7.3 Distribution of larvae???????????? 94 2.7.4 Development and the larval environment???????????? 98 2.7.5 Tolerance of environmental variables???????????? 99 2.8 Rearing methods?????????? 101 2.8.1 Spawning and manipulation of zygotes?????????? 101 2.8.2 Feeding?????????? 102 2.8.3 Control of disease in cultures?????????? 103 2.8.4 Collection of spat from wild stocks?????????? 104 References?????????? 105

Chapter 3. ?Structure and Function in Scallops Peter G. Beninger and Marcel Le Pennec

3.1 Introduction?????????? 123 3.1.1 An overview of the scallop body?????????? 123 3.2 The mantle and its derivatives?????????? 126 3.2.1 Gross functional anatomy?????????? 127 3.2.2 Microanatomy and functions?????????? 130 3.3 Pallial organs and particle processing?????????? 132 3.3.1 Gills?????????? 132 3.3.1.1 Gill axis and arch?????????? 135 3.3.1.2 Principal filaments and dorsal expansion?????????? 135 3.3.1.3 Ordinary filament?????????? 137 3.3.1.4 Haemolymph circulation in the gill?????????? 141 3.3.1.5 Particle processing on the gill?????????? 141 3.3.1.6 Particle selection at the gill?????????? 141 3.3.1.7 Particle retention lower size limit?????????? 143 3.3.1.8 Ingestion volume regulation on the gill?????????? 143 3.3.2 Labial palps and lips?????????? 144 3.3.2.1 Labial palps?????????? 144 3.3.2.2 Particle processing on the labial palps?????????? 144 3.3.2.3 Lips?????????? 147 3.4 Digestive system and digestion?????????? 150 3.4.1 Mouth and oesophagus?????????? 150 3.4.2 Stomach, crystalline style and gastric shield?????????? 150 3.4.3 The digestive gland?????????? 154 3.4.4 Intestine, rectum and anus?????????? 157 3.4.5 Digestive sites and postingestive selection?????????? 159 3.5 Cardio-Vascular system?????????? 159 3.5.1 General circulation?????????? 160 3.5.1.1 The arterial system?????????? 160 3.5.1.1.1 Anterior aorta?????????? 160 3.5.1.1.2 Posterior aorta?????????? 160 3.5.1.2 The venous system?????????? 162 3.5.2 The heart?????????? 162 3.5.2.1 The ventricle?????????? 162 3.5.2.2 The auricles and their excretory structures?????????? 163 3.5.2.3 Structure and ultrastructure of heart cells?????????? 163 3.5.2.4 Contraction?????????? 165 3.5.2.4.1 Refilling?????????? 165 3.5.2.4.2 Coordination of alternate AV beat?????????? 166 3.5.2.4.3 Pacemaker mechanism?????????? 166 3.5.2.4.4 Regulation of pacemaker?????????? 167 3.5.3 Haemolymph?????????? 167 3.5.3.1 Plasma?????????? 168 3.5.3.2 Haemocytes?????????? 168 3.5.3.2.1 Haemocyte types?????????? 169 3.5.3.2.2 Functions of haemocytes?????????? 169 3.6 Excretory system?????????? 170 3.6.1 Pericardial (auricular) glands?????????? 170 3.6.2 Kidney?????????? 172 3.6.3 Functions of the kidney and pericardial glands?????????? 173 3.7 Reproductive system?????????? 173 3.7.1 Sexuality:? Gonochory, hermaphroditism and their variants?????????? 173 3.7.2 Origin and formation of the gonad?????????? 176 3.7.3 Anatomy, histology and ultrastructure of the adult gonad?????????? 177 3.7.3.1 Outer epithelium?????????? 177 3.7.3.2 Perigonadal connective tissue?????????? 179 3.7.3.3 Inter-acinal connective tissue?????????? 179 3.7.3.4 Haemolymph sinuses?????????? 179 3.7.3.5 Acini?????????? 180 3.7.3.6 Evacuating ducts?????????? 180 3.7.4 Gametogenesis?????????? 180 3.7.4.1 Oogenesis?????????? 180 3.7.4.1.1 Premeiotic stage?????????? 180 3.7.4.1.2 Previtellogenic stage?????????? 181 3.7.4.1.3 Vitellogenesis and metabolite transport to the oocyte?????????? 181 3.7.5 Oocyte atresia?????????? 185 3.7.6 Spermatogenesis, spermatozoon ultrastructure and taxonomy?????????? 188 3.7.7 Fertilisation?????????? 190 3.8 Nervous and sensory systems?????????? 191 3.8.1 General organisation of the nervous system and functional anatomy of principal ganglia?????????? 191 3.8.1.1 Cerebral and pedal ganglia?????????? 191 3.8.1.2 The parietovisceral ganglion and its nerves?????????? 191 3.8.1.3 Histology and neurosecretions of the ganglia?????????? 196 3.8.1.4 The circumpallial nerve?????????? 198 3.8.2 Sensory structures?????????? 198 3.8.2.1 Visual system?????????? 198 3.8.2.2 Epithelial sensory cells and tentacles?????????? 198 3.8.2.3 Abdominal sense organ?????????? 199 3.8.2.4 Osphradia?????????? 201 3.8.2.5 Statoreceptors?????????? 204 3.8.3 Neurotransmitters and neurohormones?????????? 204 3.9 Foot-byssal complex?????????? 205 3.9.1 External morphology and development of the foot-byssal complex?????????? 207 3.9.2 Anatomy and histology of the foot-byssal gland complex?????????? 208 3.9.2.1 The protein gland?????????? 208 3.9.2.2 The enzyme gland?????????? 208 3.9.2.3 The byssus?????????? 210 3.9.3 Functioning of the foot-byssal complex?????????? 210 Acknowledgments?????????? 210 References?????????? 211

Chapter 4. ?Scallop Adductor Muscles: Structure and Function Peter D. Chantler

4.1 Introduction?????????? 229 4.2 Structure of the striated adductor muscle?????????? 231 4.2.1 Fibre microanatomy?????????? 231 4.2.2 Actin and thin filament structure?????????? 233 4.2.3 Thick filament structure?????????? 240 4.3 Structure of the smooth adductor muscle?????????? 243 4.3.1 Fibre microanatomy?????????? 243 4.3.2 Thin filament structure?????????? 245 4.3.3 The structure of paramyosin-rich thick filaments?????????? 247 4.4 Myosin?????????? 253 4.5 Function of the striated adductor?????????? 271 4.5.1 Mechanics?????????? 271 4.5.2 The interaction of myosin with actin?????????? 272 4.5.3 The crossbridge cycle?????????? 277 4.5.4 Myosin-linked regulation?????????? 282 4.6 Function of the smooth adductor?????????? 289 4.6.1 Physiology?????????? 289 4.6.2 Catch mechanism?????????? 292 4.7 Achievements and goals?????????? 296 Acknowledgments?????????? 298 References?????????? 298

Chapter 5. ?Neurobiology and Behaviour of the Scallop Lon A. Wilkens

5.1 Introduction?????????? 317 5.2 The visual system?????????? 317 5.2.1 Functional anatomy of the eyes?????????? 317 5.2.2 Retinal physiology?????????? 322 5.2.3 Receptor potential biophysics?????????? 324 5.2.4 Anatomy and physiology of vision in the central nervous system?????????? 328 5.2.5 Visual behaviours?????????? 332 5.3 The locomotory system?????????? 335 5.3.1 Escape responses and swimming?????????? 335 5.3.2 Sensory and motor functions of the mantle?????????? 341 5.3.3 Innervation and neuromuscular physiology of the adductor muscle?????????? 345 5.3.4 Coordination of locomotory behaviour by the central nervous system?????????? 348 Acknowledgments?????????? 352 References?????????? 352

Chapter 6. ?Reproductive Physiology Bruce J. Barber and Norman J. Blake

6.1 Introduction?????????? 357 6.2 Gametogenic cycles?????????? 358 6.2.1 Definition?????????? 358 6.2.2 Means of assessment?????????? 358 6.2.2.1 Visual observation?????????? 360 6.2.2.2 Gonad mass and index?????????? 360 6.2.2.3 Histology?????????? 367 6.2.2.4 Abundance of larvae and spat?????????? 369 6.2.3 Variations in gametogenic cycles?????????? 370 6.2.3.1 Intra-specific variations?????????? 370 6.2.3.2 Inter-specific variations?????????? 375 6.3 Regulation of gametogenic cycles?????????? 375 6.3.1 Gametogenesis and fecundity?????????? 376 6.3.1.1 Exogenous regulation?????????? 376 6.3.1.2 Endogenous regulation?????????? 381 6.3.2 Spawning and spawning synchrony?????????? 385 6.3.2.1 Exogenous regulation?????????? 385 6.3.2.2 Endogenous regulation?????????? 389 6.4 Energy metabolism?????????? 390 6.4.1 Tissue weights and indices?????????? 391 6.4.2 Tissue biochemical composition?????????? 392 6.4.3 Physiological indices?????????? 395 6.4.4 Radiotracer experiments?????????? 398 6.4.5 Ultrastructure and histochemistry?????????? 398 6.4.6 Mechanisms?????????? 400 6.5 Applications to aquaculture?????????? 401 6.5.1 Broodstock conditioning?????????? 401 6.5.2 Spawning?????????? 403 6.5.3 Larval growth and survival?????????? 403 6.6 Summary?????????? 404 6.6.1 Gametogenic cycles?????????? 404 6.6.2 Regulation of gametogenesis?????????? 404 6.6.3 Energy metabolism?????????? 405 6.6.4 Applications to aquaculture?????????? 406 References?????????? 406

Chapter 7. ?Physiology: Energy Acquisition and Utilisation Bruce A. MacDonald, V. Monica Bricelj and Sandra E. Shumway

7.1 Introduction?????????? 417 7.2 Energy acquisition?????????? 417 7.2.1 Food sources?????????? 417 7.2.2 Feeding currents and mechanisms of particle capture?????????? 420 7.2.3 Particle retention efficiency?????????? 421 7.2.4 Feeding rates?????????? 424 7.2.5 Clearance rate in relation to food concentration?????????? 427 7.2.6 Influence of temperature on feeding rates?????????? 430 7.2.7 Pseudofeces production, pre- and post-ingestive particle selection?????????? 432 7.2.8 Absorption efficiency?????????? 436 7.2.9 Effects of suspended sediments on feeding and growth?????????? 439 7.2.10 Effects of flow on feeding and growth?????????? 445 7.2.11 Effects of harmful and toxic algae?????????? 447 7.3 Energy utilisation: Metabolic expenditure?????????? 453 7.3.1 Metabolic rate and oxygen availability?????????? 455 7.3.2 Metabolic cost of reproduction?????????? 458 7.3.3 Metabolic rate in relation to temperature and latitude?????????? 460 7.3.4 Metabolic rate in relation to activity levels?????????? 461 7.3.5 Anaerobic metabolism?????????? 463 7.4 Energy utilisation?????????? 467 7.4.1 Excretion and byssus secretion?????????? 467 7.4.2 Growth?????????? 468 References?????????? 474

Chapter 8. ?Physiological Integrations and Energy Partitioning Raymond J. Thompson and Bruce A. MacDonald

8.1 Introduction?????????? 493 8.2 Energy balance, physiological integrations and the partitioning of energy between growth and reproduction?????????? 493 8.2.1 Energy budgets?????????? 493 8.2.2 Scope for growth?????????? 494 8.2.3 Growth efficiency and turnover ratio?????????? 494 8.2.4 Growth of shell and somatic tissue?????????? 495 8.2.5 Reproductive effort?????????? 496 8.3 Changes related to age of individuals?????????? 498 8.3.1 Scope for growth?????????? 498 8.3.2 Growth efficiency and turnover ratio?????????? 498 8.3.3 Somatic growth and maximum size?????????? 499 8.3.4 Somatic production and reproductive output?????????? 500 8.3.5 Reproductive effort?????????? 502 8.4 Environmental influence on production?????????? 504 8.4.1 Scope for growth and growth efficiency?????????? 504 8.4.2 Growth of shell and somatic tissue?????????? 506 8.4.3 Reproductive effort?????????? 509 8.5 Reproductive value and cost?????????? 511 8.5.1 Residual reproductive value?????????? 511 8.5.2 Reproductive cost?????????? 512 8.6 Population production?????????? 514 Acknowledgments?????????? 516 References?????????? 516

Chapter 9. ?Nutrition in Pectinids Ana Farias and Iker Uriarte

9.1 Introduction?????????? 521 9.2 Pectinid feeding?????????? 521 9.3 Nutritional requirements during reproductive conditioning?????????? 528 9.4 Nutritional requirements of the larvae?????????? 529 9.5 Post-metamorphic nutritional requirements?????????? 533 9.6 Summary?????????? 536 References?????????? 536

Chapter 10. ?Genetics Andy Beaumont

10.1 Introduction?????????? 543 10.2 Chromosomal genetics and ploidy manipulation?????????? 544 10.2.1 Chromosome numbers and karyotypes?????????? 544 10.2.2 Ploidy manipulation?????????? 548 10.3 Genetic markers and population genetics?????????? 550 10.3.1 Genetic markers?????????? 550 10.3.1.1 Allozymes?????????? 551 10.3.1.2 DNA methods?????????? 551 10.3.1.3 DNA based markers?????????? 552 10.3.1.3.1 Restriction fragment length polymorphism (RFLP)?????????? 552 10.3.1.3.2 Random amplified polymorhic DNA (RAPDs)?????????? 552 10.3.1.3.3 Microsatellites?????????? 553 10.3.1.3.4 Amplified fragment length polymorphism (AFLP)?????????? 553 10.3.1.4 Mitochondrial DNA in scallops?????????? 554 10.3.1.5 Types of data produced by different markers?????????? 555 10.3.1.6 Analysis of data?????????? 555 10.3.2 Overall genetic variation?????????? 557 10.3.3 Genetic differentiation of populations?????????? 559 10.3.3.1 Placopecten magellanicus?????????? 559 10.3.3.2 Patinopecten (= Mizuhopecten) yessoensis?????????? 561 10.3.3.3 Pecten maximus?????????? 562 10.3.3.4 Aequipecten opercularis?????????? 563 10.3.3.5 Chlamys islandica?????????? 564 10.3.3.6 Chlamys farreri?????????? 565 10.3.3.7 Mimachlamys varia?????????? 565 10.3.3.8 Euvola (Pecten) ziczac?????????? 565 10.3.3.9 Argopecten gibbus?????????? 565 10.3.3.10 The Argopecten irradians species complex?????????? 566 10.3.4 Genetic differences at species level and above?????????? 567 10.3.5 Heterozygote deficiency?????????? 568 10.3.6 Heterozygosity and growth?????????? 571 10.4 Quantitative genetics?????????? 575 10.4.1 Heritability and artificial selection?????????? 575 10.4.2 Inbreeding and hybridisation?????????? 577 10.5 Genome mapping and gene sequences?????????? 579 10.6 Conclusion?????????? 580 Acknowledgments?????????? 581 References?????????? 581

Chapter 11. ?Diseases and Parasites of Scallops Sharon E. McGladdery, Susan M. Bower and Rodman G. Getchell

11.1 Introduction?????????? 595 11.2 Microbial diseases?????????? 595 11.2.1 Viruses?????????? 595 11.2.2 Prokaryota?????????? 605 11.2.2.1 Vibrionaceae?????????? 605 11.2.2.2 Intracellular prokaryotes (Rickettsiales; Chlamydiales and Mycoplasma)?????????? 607 11.2.2.3 Other bacterial pathogens of scallops?????????? 610 11.2.2.4 Bacterial management under hatchery conditions?????????? 611 11.3 Mycota?????????? 612 11.4 Protista?????????? 614 11.4.1 Sarcomastigophorea (Amoebae and Flagellates)?????????? 614 11.4.2 Labyrinthomorpha (Thraustochytrids and Labythinuloids)?????????? 615 11.4.3 Apicomplexa?????????? 615 11.4.3.1 Perkinsorida?????????? 615 11.4.3.2 Eucoccidiia?????????? 617 11.4.3.3 Eugregarinida?????????? 618 11.4.4 Microspora?????????? 619 11.4.5 Ascetospora?????????? 620 11.4.5.1 Marteiliida?????????? 621 11.4.5.2 Balanosporida?????????? 621 11.4.6 Ciliates?????????? 621 11.5 Platyhelminths?????????? 623 11.5.1 Trematodes?????????? 623 11.5.2 Cestodes?????????? 626 11.5.3 Turbellaria?????????? 626 11.5.4 Nematodes?????????? 628 11.6 Polychaetes?????????? 629 11.7 Crustacea?????????? 632 11.7.1 Pinnotheriidae?????????? 632 11.7.2 Copepodidae?????????? 632 11.8 Gastropods?????????? 633 11.9 Algae?????????? 635 11.10 Foraminiferans?????????? 636 11.11 Porifera?????????? 636 11.12 Cnidaria?????????? 637 11.13 Non-Infectious diseases?????????? 638 11.14 Summary?????????? 638 Acknowledgments?????????? 639 References?????????? 639

Chapter 12. ?Scallop Ecology: Distributions and Behaviour Andrew R. Brand

12.1 Introduction?????????? 651 12.2 Geographical distribution?????????? 653 12.2.1 Geographical distribution of commercially important species?????????? 653 12.2.1.1 North Atlantic species?????????? 653 12.2.1.1.1 Pecten maximus and P. jacobaeus?????????? 653 12.2.1.1.2 Aequipecten opercularis?????????? 655 12.2.1.1.3 Mimachlamys varia?????????? 655 12.2.1.1.4 Placopecten magellanicus?????????? 655 12.2.1.1.5 Argopecten irradians?????????? 657 12.2.1.1.6 Argopecten gibbus?????????? 659 12.2.1.2 Sub-arctic species?????????? 659 12.2.1.2.1 Chlamys islandica?????????? 659 12.2.1.3 North Pacific species?????????? 661 12.2.1.3.1 Patinopecten caurinus?????????? 661 12.2.1.3.2 Mizuhopecten yessoensis?????????? 661 12.2.1.3.3 Pecten albicans, Mimachlamys nobilis and Chlamys farreri?????????? 662 12.2.1.4 Southern hemisphere species?????????? 662 12.2.1.4.1 Pecten fumatus?????????? 662 12.2.1.4.2 Mimachlamys asperrima and Equichlamys bifrons?????????? 663 12.2.1.4.3 Amusium balloti and A. pleuronectes?????????? 664 12.2.1.4.4 Pecten novaezelandiae?????????? 664 12.2.1.4.5 Argopecten purpuratus and A. ventricosus?????????? 665 12.2.1.4.6 Aequipecten tehuelchus?????????? 665 12.2.1.4.7 Zygochlamys patagonica?????????? 665 12.2.2 Factors affecting geographical distribution?????????? 666 12.3 Local distribution?????????? 669 12.3.1 Spatial distribution?????????? 669 12.3.2 Year-class separation?????????? 676 12.3.3 Factors affecting local distribution?????????? 677 12.3.3.1 Depth?????????? 678 12.3.3.2 Substrate type?????????? 678 12.3.3.3 Currents?????????? 679 12.3.3.4 Turbidity?????????? 680 12.3.3.5 Salinity?????????? 681 12.3.3.6 Competitors and predators?????????? 684 12.4 Scallop behaviour - aspects affecting distribution?????????? 689 12.4.1 Byssus attachment?????????? 689 12.4.2 Recessing?????????? 692 12.4.3 Orientation?????????? 695 12.4.4 Swimming?????????? 698 12.4.5 Reactions to predators?????????? 707 12.4.6 Dispersal and migrations?????????? 709 12.5 Further study?????????? 712 Acknowledgments?????????? 713 References?????????? 713

Chapter 13. ?Scallops and Marine Contaminants Peter J. Cranford

13.1 Introduction?????????? 745 13.2 Trace metals?????????? 746 13.3 Trace organics?????????? 748 13.4 Offshore oil and gas operations?????????? 750 13.5 Scallops as sentinel organisms?????????? 754 Acknowledgments?????????? 759 References?????????? 759

Chapter 14. ?Dynamics, Assessment and Management of Exploited Natural Populations J.M. (Lobo) Orensanz, Ana M. Parma, Teresa Turk and Juan Valero

14.1 Introduction?????????? 765 14.2 Spatial scales?????????? 765 14.3 Population structure and dynamics?????????? 769 14.3.1 Aggregate stocks?????????? 769 14.3.1.1 Patterns of fluctuation?????????? 769 14.3.1.2 Climatic forcing?????????? 771 14.3.1.3 Correlation between consecutive life-history stages?????????? 773 14.3.1.4 The relation between aggregate stock and settlement/ recruitment?????????? 774 14.3.2 Macroscale?????????? 777 14.3.2.1 Patterns of connectivity: metapopulation structure?????????? 777 14.3.2.2 Metapopulation structure and geographic genetic differentiation?????????? 780

14.3.2.3 Larval retention/dispersal: mechanisms and oceanographic scenarios?????????? 782 14.3.2.4 Metapopulation models ?????????? 784 14.3.3 Mesoscale?????????? 785 14.3.3.1 Persistence, extinction and resurgence of subpopulations?????????? 785 14.3.3.2 Relation between abundance and area occupied by a subpopulation?????????? 785 14.3.4 Microscale?????????? 786 14.3.4.1 Density, neighbourhoods and concentration?????????? 786 14.3.4.2 Concentration profiles?????????? 788 14.3.4.3 Density- vs. concentration-dependence; compensation vs. depensation?????????? 789 14.4 The fishing process?????????? 795 14.4.1 Types of fishing gear used in scallop fisheries?????????? 796 14.4.2 Effort and fishing mortality?????????? 797 14.4.2.1 Effort data?????????? 797 14.4.2.2 Effort units?????????? 797 14.4.2.3 Components of fishing mortality under homogeneity assumptions?????????? 798 14.4.2.4 Relative fishing power and standardisation of effort?????????? 799 14.4.3 Spatial patterns of effort allocation?????????? 799 14.4.4 The depletion process?????????? 803 14.4.5 Vulnerability and selectivity?????????? 805 14.4.6 Gear performance?????????? 806 14.4.7 Incidental fishing mortality and sub-lethal damage?????????? 808 14.5 Assessment?????????? 811 14.5.1 Macroscale?????????? 811 14.5.2 Mesoscale?????????? 812 14.5.2.1 Estimation of aggregated abundance: methods based on sampling?????????? 812 14.5.2.2 Mapping?????????? 815 14.5.2.3 Methods based on modelling the depletion process?????????? 816 14.5.3 Microscale?????????? 819 14.5.3.1 Small-scale spatial data?????????? 819 14.5.3.2 Spatial pattern?????????? 820 14.5.3.3 Scaling problems?????????? 821 14.6 Management?????????? 823 14.6.1 Types of scallop fisheries?????????? 823 14.6.2 Overfishing?????????? 824 14.6.2.1 Growth overfishing: yield-per-recruit (Y/R) analysis?????????? 824 14.6.2.2 Recruitment overfishing?????????? 826 14.6.2.3 A special case: recruitment fisheries?????????? 829 14.6.3 Sustainability?????????? 830

14.6.3.1 The precautionary approach to fisheries management (PAFM) and risk assessment (RA) ?????????? 830 14.6.3.2 Marine protected areas (MPAs) ?????????? 832 14.6.3.3 Ecosystem management concerns?????????? 834 14.6.3.4 Strategic structures: use and property rights?????????? 835 14.6.3.5 Diversification of the resource-base?????????? 837 14.6.4 Tactics?????????? 838 14.6.4.1 Size limits?????????? 838 14.6.4.2 Quota regulations?????????? 840 14.6.4.3 Escapement regulations?????????? 840 14.6.4.4 Direct effort regulations?????????? 840 14.6.4.5 Rotation?????????? 841 14.6.4.6 Direct interventions to enhance productivity?????????? 842 14.6.4.7 Experimental management?????????? 844 Acknowledgments?????????? 844 References?????????? 844 Endnotes?????????? 867

Chapter 15. ?Fisheries Sea Scallop, Placopecten magellanicus K.S. Naidu and G. Robert

15.1 Introduction?????????? 869 15.2 Distribution?????????? 871 15.3 History of fishery?????????? 874 15.4 Population biology?????????? 878 15.5 Growth and yield per recruit?????????? 880 15.6 Gear and boats?????????? 883 15.7 Exploitation and resource management?????????? 886 15.8 Outlook?????????? 895 References?????????? 897

Chapter 16. ?Sea Scallop Aquaculture in the Northwest Atlantic G. Jay Parsons and Shawn M. C. Robinson

16.1 Introduction?????????? 907 16.2 History of sea scallop culture?????????? 908 16.3 Hatchery spat production?????????? 909 16.3.1 Broodstock conditioning?????????? 909 16.3.2 Spawning methods?????????? 910 16.3.3 Egg and larval development?????????? 910 16.3.4 Settlement and metamorphosis?????????? 911 16.3.5 Spat husbandry?????????? 911 16.4 Wild spat collection?????????? 912 16.4.1 Spat collection techniques?????????? 912 16.4.2 Settlement intensity?????????? 913 16.4.3 Maximising spat collection?????????? 914 16.4.4 Spat growth?????????? 916 16.4.5 Spat sorting?????????? 916 16.5 Intermediate culture?????????? 916 16.5.1 Growth?????????? 917 16.5.2 Stocking density?????????? 917 16.5.3 Depth?????????? 919 16.5.4 Season?????????? 919 16.5.5 Location?????????? 919 16.5.6 Survival?????????? 920 16.5.7 Gear selection?????????? 920 16.5.8 Strategies for intermediate culture?????????? 921 16.6 Final grow-out?????????? 922 16.6.1 Suspension culture?????????? 922 16.6.2 Bottom culture?????????? 922 16.6.3 Growth?????????? 923 16.7 Scheduling and strategies?????????? 924 16.8 Site selection?????????? 924 16.8.1 Environmental criteria?????????? 925 16.8.1.1 Temperature and salinity regime?????????? 925 16.8.1.2 Ice coverage?????????? 925 16.8.1.3 Wind?????????? 925 16.8.1.4 Bottom type?????????? 925 16.8.1.5 Turbidity?????????? 926 16.8.2 Biological constraints?????????? 926 16.8.2.1 Predators?????????? 926 16.8.2.2 Fouling organisms?????????? 926 16.8.2.3 Phycotoxins?????????? 926 16.8.2.4 Diseases and parasites?????????? 927 16.9 Products and marketing?????????? 928 16.10 Economics?????????? 928 16.11 Social issues?????????? 929 16.12 Future prospects?????????? 930 Acknowledgments?????????? 930 References?????????? 930

Chapter 17. ?Bay Scallop and Calico Scallop Fisheries, Culture and Enhancement in Eastern North America Norman J. Blake and Sandra E. Shumway

17.1 Introduction?????????? 945 17.2 Fisheries?????????? 945 17.2.1 Bay scallop, Argopecten irradians?????????? 945 17.2.1.1 Distribution?????????? 945 17.2.1.2 Biology?????????? 948 17.2.1.3 Fishery?????????? 950 17.2.2 Calico scallop, Argopecten gibbus?????????? 952 17.2.2.1 Distribution?????????? 952 17.2.2.2 Biology?????????? 953 17.2.2.3 Fishery?????????? 955 17.3 Aquaculture and enhancement?????????? 958 17.4 Future?????????? 961 References?????????? 961

Chapter 18. ?Scallops of the West Coast of North America Raymond B. Lauzier and Neil F. Bourne

18.1 Introduction?????????? 965 18.2 Fisheries?????????? 967 18.2.1 Weathervane scallop?????????? 967 18.2.1.1 Biology?????????? 967 18.2.1.2 Fishery?????????? 971 18.2.1.3 Gear?????????? 973 18.2.1.4 Management?????????? 973 18.2.2 Rock scallop?????????? 973 18.2.2.1 Biology?????????? 974 18.2.2.2 Fishery?????????? 975 18.2.3 Pink and spiny scallops?????????? 975 18.2.3.1 Biology?????????? 975 18.2.3.2 Fisheries?????????? 977 18.2.3.3 Management?????????? 979 18.3 Aquaculture?????????? 979 18.3.1 Pink and spiny scallops?????????? 980 18.3.2 Weathervane scallop?????????? 980 18.3.3 Rock scallops?????????? 981 18.3.4 Japanese weathervane scallop?????????? 982 18.3.5 Pacific calico scallop?????????? 983 18.4 Future?????????? 983 Acknowledgments?????????? 984 References?????????? 984

Chapter 19. ?The European Scallop Fisheries for Pecten maximus, Aequipecten opercularis and Mimachlamys varia Andrew R. Brand

19.1 Introduction?????????? 991 19.2 Biology and ecology?????????? 993 19.2.1 The great scallop, Pecten maximus (L.)?????????? 993 19.2.2 The queen scallop, Aequipecten opercularis (L.)???????? 1006 19.2.3 The black or variegated scallop, Mimachlamys varia (L.)???????? 1011 19.3 Fisheries???????? 1014 19.3.1 Isle of Man???????? 1017 19.3.2 Scotland???????? 1023 19.3.3 England and Wales???????? 1025 19.3.4 Northern Ireland???????? 1027 19.3.5 Republic of Ireland???????? 1027 19.3.6 France???????? 1029 19.3.7 Spain???????? 1031 19.4 The future???????? 1031 Acknowledgments???????? 1035 References???????? 1035

Chapter 20. ?European Aquaculture Mark Norman, Guillermo Roman and Øivind Strand

20.1 Introduction???????? 1059 20.2 Pecten maximus???????? 1060 20.3 Aequipecten opercularis???????? 1062 20.4 Chlamys varia???????? 1063 20.5 Summary???????? 1063 References???????? 1063

Chapter 21. ?Scandinavia Øivind Strand and G. Jay Parsons

21.1 Introduction???????? 1067 21.2 Chlamys islandica???????? 1067 21.2.1 Biology???????? 1067 21.2.2 Fishery???????? 1073 21.2.3 Aquaculture???????? 1076 21.3 Pecten maximus???????? 1077 21.3.1 Biology???????? 1077 21.3.2 Fishery???????? 1078 21.3.3 Aquaculture???????? 1079 21.4 Aequipecten opercularis???????? 1085 Acknowledgments???????? 1086 References???????? 1086

Chapter 22. ?Japan Yoshinobu Kosaka and Hiroshi Ito

22.1 Introduction???????? 1093 22.2 Patinopecten (Mizuhopecten) yessoensis???????? 1099 22.2.1 Biology???????? 1099 22.2.2 Fishery???????? 1104 22.2.3 Culture???????? 1111 22.2.4 Seed production???????? 1111 22.2.5 Spat collection???????? 1111 22.2.6 Intermediate culture???????? 1116 22.2.7 Hanging culture???????? 1116 22.2.8 Fouling???????? 1118 22.2.9 Sowing culture???????? 1120 22.2.10 Enemy clearance???????? 1120 22.2.11 Seed sowing???????? 1120 22.2.12 Care???????? 1121 22.2.13 Recapture???????? 1121 22.2.14 Value???????? 1124 22.2.15 Processing???????? 1127 22.2.16 Occurrence of shellfish poisoning???????? 1130 22.3 Future???????? 1130 22.3.1 Technology???????? 1130 22.3.2 Control of culture???????? 1133 22.3.3 Cost-reduction???????? 1133 22.3.4 Concept???????? 1133 22.4 Pecten albicans???????? 1134 22.4.1 Biology???????? 1134 22.4.2 Fishery???????? 1134 22.4.3 Culture???????? 1135 22.5 Chlamys (Mimachlamys) nobilis???????? 1135 22.5.1 Biology???????? 1135 22.5.2 Culture???????? 1135 Acknowledgments???????? 1136 References???????? 1136

Chapter 23. ?Scallop Culture in China Ximing Guo and Yousheng Luo

23.1 Introduction???????? 1141 23.2 Zhikong scallop???????? 1146 23.2.1 Shell morphology???????? 1146 23.2.2 Distribution???????? 1146 23.2.3 Growth???????? 1147 23.2.4 Reproduction???????? 1149 23.3 Other scallop species???????? 1151 23.3.1 Huagui scallop???????? 1151 23.3.2 Non-native species???????? 1152 23.4 Fishery???????? 1153 23.5 Aquaculture???????? 1154 23.5.1 Species and history???????? 1154 23.5.2 Collection of natural seed for Zhikong scallop???????? 1155 23.5.3 Hatchery production of bay scallop???????? 1155 23.5.4 Grow-out???????? 1158 23.6 Harvest, processing and marketing???????? 1160 Acknowledgments???????? 1160 References???????? 1161

Chapter 24. ?Scallops Fisheries and Aquaculture of Northwestern Pacific, Russian Federation Victor V. Ivin, Vasily Z. Kalashnikov, Sergey I. Maslennikov and Vitaly G. Tarasov

24.1 Introduction???????? 1163 24.2 Taxonomic status???????? 1163 24.3 Biology and ecology???????? 1164 24.3.1 Chlamys albida???????? 1164 24.3.2 Chlamys asiatica???????? 1166 24.3.3 Chlamys behringiana???????? 1167 24.3.4 Chlamys chosenica???????? 1168 24.3.5 Chlamys farreri???????? 1170 24.3.6 Chlamys swifti???????? 1172 24.3.7 Delectopecten randolphi???????? 1174 24.3.8 Mizuhopecten yessoensis???????? 1174 24.3.8.1 Total populations and biomass???????? 1175 24.3.8.2 Distribution in Primorye???????? 1176 24.3.8.3 Distribution over depths???????? 1176 24.3.8.4 Age structure of scallop settlements???????? 1176 24.3.8.5 Scallop growth???????? 1177 24.3.8.6 Sex structure of settlements???????? 1178 24.3.8.7 Replenishment???????? 1181 24.3.8.8 Spawning???????? 1181 24.3.8.9 Larvae morphology???????? 1182 24.3.8.10 Development in plankton???????? 1182 24.3.8.11 Migration behaviour???????? 1184 24.3.8.12 Risk factors???????? 1184 24.3.8.12.1 Abiotic factors???????? 1184 24.3.8.12.2 Storms???????? 1184 24.3.8.12.3 Predators???????? 1185 24.3.8.12.4 Parasites???????? 1187 24.3.8.12.5 Bacterial contamination???????? 1189 24.3.8.12.6 Epibionts???????? 1189 24.4 Fishing and aquaculture???????? 1189 24.4.1 Fishing???????? 1189 24.4.1.1 History???????? 1189 24.4.1.2 Fishing gear???????? 1191 24.4.1.3 Yesso scallop landings???????? 1191 24.4.1.3.1 Primorsky territory???????? 1191 24.4.1.3.2 Sakhalin-Kurile region???????? 1192 24.4.1.4 Yesso scallop commercial stock???????? 1192 24.4.1.4.1 Primorsky territory???????? 1192 24.4.1.4.2 Sakhalin-Kurile region???????? 1192 24.4.1.4.2.1 Aniva Bay???????? 1194 24.4.1.4.2.2 Terpenie Bay???????? 1194 24.4.1.4.2.3 Kuriles???????? 1194 24.4.1.5 Commercial Chlamys scallops???????? 1194 24.4.1.5.1 Primorye???????? 1194 24.4.1.5.2 Kurile Islands???????? 1195 24.4.1.5.3 In Bering Sea???????? 1196 24.4.1.6 Other Chlamys species???????? 1196 24.4.1.6.1 Chlamys farreri???????? 1196 24.4.1.6.2 Chlamys swifti???????? 1196 24.4.2 Aquaculture???????? 1196 24.4.2.1 History???????? 1196 24.4.2.2 Present situation???????? 1197 24.4.2.3 Marketing???????? 1198 24.4.2.4 The culture methods???????? 1198 24.4.2.4.1 Spat collection???????? 1198 24.4.2.4.2 Intermediate culture???????? 1199 24.4.2.4.3 Transport of scallop seed???????? 1199 24.4.2.4.4 Sowing or on-bottom culture???????? 1200 24.4.2.4.5 Hanging or off-bottom culture???????? 1201 24.4.2.4.6 Obstacles to mariculture development???????? 1201 24.4.2.4.7 Ecological constraints associated with cultivation???????? 1202 24.4.2.4.7.1 Predation???????? 1202 24.4.2.4.7.2 Epibionts???????? 1202 24.4.2.4.7.3 Biofouling of cultivation structures???????? 1203 24.4.2.4.8 Effect of scallop mariculture on coastal ecosystems???????? 1204 24.4.2.5 Future prospects???????? 1211 Acknowledgments???????? 1213 References???????? 1213

Chapter 25. ?Scallop Aquaculture and Fisheries in Brazil Guilherme S. Rupp and G. Jay Parsons

25.1 Introduction???????? 1225 25.2 Nodipecten nodosus ? biology, aquaculture and fisheries???????? 1227 25.2.1 Taxonomy and distribution???????? 1227 25.2.2 Ecology???????? 1228 25.2.3 Reproduction???????? 1231 25.2.4 Aquaculture???????? 1232 25.2.4.1 Status???????? 1232 25.2.4.2 Culture technology???????? 1233 25.2.4.2.1 Wild seed collection???????? 1233 25.2.4.2.2 Hatchery production???????? 1234 25.2.4.2.3 Growout???????? 1236 25.2.4.2.4 Constraints???????? 1239 25.2.5 Fisheries and marketing???????? 1239 25.2.6 Future prospects???????? 1240 25.3 Euvola (Pecten) ziczac ? biology, aquaculture and fisheries???????? 1240 25.3.1 Taxonomy and distribution???????? 1240 25.3.2 Ecology???????? 1241 25.3.3 Reproduction???????? 1241 25.3.4 Aquaculture???????? 1242 25.3.4.1 Status???????? 1242 25.3.4.2.Culture technology???????? 1242 25.3.4.2.1 Wild seed collection???????? 1242 25.3.4.2.2 Hatchery production???????? 1242 25.3.4.2.3 Growout???????? 1243 25.3.4.2.4 Constraints???????? 1243 25.3.5 Fisheries???????? 1243 25.3.6 Future prospects???????? 1244 Acknowledgments???????? 1244 References???????? 1245

Chapter 26. ?Argentina Nestor F. Ciocco, Mario L. Lasta, Maite Narvarte, Claudia Bremec, Eugenia Bogazzi, Juan Valero and J.M. (Lobo) Orensanz

26.1 Introduction???????? 1251 26.2 The Tehuelche scallop, Aequipecten tehuelchus???????? 1251 26.2.1 Biology???????? 1251 26.2.2 Population dynamics???????? 1257 26.2.3 Fisheries???????? 1258 26.2.3.1 The inshore dredge fishery of San Matias Gulf???????? 1258 26.2.3.2 The commercial diving fishery of San Jose Gulf???????? 1261 26.2.4 Aquaculture???????? 1263 26.2.4.1 Spat collection???????? 1263 26.2.4.1.1 Vertical distribution of settlement???????? 1263 26.2.4.1.2 Temporal variation in settlement???????? 1263 26.2.4.1.3 Type of collector???????? 1263 26.2.4.1.4 Location???????? 1265 26.2.4.1.5 Influence of depth, type of collector and location on the average size of the ‘seed’???????? 1265 26.2.4.2 Growth in suspended structures of spat obtained from collectors???????? 1266 26.2.4.3 Larval culture in the laboratory???????? 1268 26.2.4.4 Prospects and problems???????? 1268 26.3 The Patagonian scallop, Zygochlamys patagonica???????? 1269 26.3.1 Biology and ecology???????? 1269 26.3.2 Population dynamics and stock assessment???????? 1273 26.3.3 The fishery???????? 1275 26.3.3.1 Exploratory surveys and experimental fishing programs???????? 1275 26.3.3.2 Management???????? 1276 26.3.3.3 Development of the fishery???????? 1277 26.3.3.4 Observers program???????? 1280 26.3.3.5 Ecological effects of fishing???????? 1281 26.3.3.6 Marketing???????? 1283 Acknowledgments???????? 1283 References???????? 1283

Chapter 27. ?Scallop Fishery and Aquaculture in Chile Elisabeth von Brand, German E. Merino, Alejandro Abarca and Wolfgang Stotz

27.1 Introduction???????? 1293 27.2 Species description???????? 1293 27.2.1 Argopecten purpuratus (Lamarck 1819) the northern scallop???????? 1295 27.2.2 Zygochlamys patagonica (King and Broderip 1831) the southern scallop???????? 1295 27.2.3 Chlamys vitrea (King & Broderip, 1831) the southern scallop….???????? 1296 27.3 Fisheries???????? 1296 27.3.1 Argopecten purpuratus, the northern scallop???????? 1296 27.3.2 Chlamys vitrea and Zygochlamys patagonica, the southern scallop???????? 1298 27.4 How scallop aquaculture started in Chile???????? 1299 27.5 Aquaculture production???????? 1301 27.5.1 Production stages???????? 1303 27.5.1.1 Hatchery broodstock conditioning and spawning???????? 1303 27.5.1.2 Larval stage???????? 1303 27.5.1.3 Settlement, metamorphosis and postlarval stage???????? 1304 27.5.1.4 Seed supply???????? 1305 27.5.1.5 Ongrowing stage???????? 1305 27.5.2 Constraints and opportunities for northern scallop hatcheries???????? 1306 27.5.3 Interaction between natural beds and aquaculture???????? 1307 27.5.4 Recovery of a natural bed of Argopecten purpuratus???????? 1308 27.5.5 Final overview and projections of Chilean scallop farming???????? 1308 Acknowledgments???????? 1311 References???????? 1311

Chapter 28. ?Venezuela Cesar J. Lodeiros, Luis Freites, Maximiano Nunez, Anibal Velez and John H. Himmelman

28.1 Introduction???????? 1315 28.2 Distribution, habitat and reproduction???????? 1315 28.2.1 Euvola (Pecten) ziczac???????? 1315 28.2.2 Argopecten nucleus???????? 1319 28.2.3 Nodipecten (Lyropecten) nodosus???????? 1319 28.2.4 Amusium papyraceum and Amusium laurenti???????? 1320 28.3 Fisheries???????? 1320 28.4 Aquaculture???????? 1322 28.4.1 Euvola ziczac???????? 1322 28.4.1.1 Gonad maturation and spawning???????? 1322 28.4.1.2 Spat production???????? 1322 28.4.1.3 Grow-out???????? 1323 28.4.2 Nodipecten nodosus???????? 1326 28.4.2.1 Gonad maturation and spawning???????? 1326 28.4.2.2 Spat production???????? 1326 28.4.2.3 Grow-out???????? 1326 28.4.3 Argopecten nucleus???????? 1329 28.5 Perspectives for culture???????? 1330 References???????? 1332

Chapter 29. ?Mexico Esteban Fernando Felix-Pico

29.1 Fishery???????? 1337 29.1.1 Introduction???????? 1337 29.1.2 Species and distribution of scallops???????? 1338 29.1.3 History of the fishery???????? 1339 29.1.4 Status of the resource???????? 1340 29.1.4.1 Reproductive biology???????? 1340 29.1.4.1.1 Size at maturity???????? 1340 29.1.4.1.2 Fecundity???????? 1341 29.1.4.1.3 Maturity and spawning???????? 1341 29.1.4.2 Population biology???????? 1344 29.1.4.3 Abundance and density???????? 1345 29.2 Exploitation of the resource???????? 1347 29.2.1 Fishing areas???????? 1347 29.2.2 Fishing seasons???????? 1348 29.2.3 Fishing operations and results???????? 1349 29.2.4 The market value-landings data from 1970 to 2000???????? 1349 29.3 Constraints???????? 1350 29.3.1 Pollution???????? 1350 29.3.2 Biological constraints???????? 1352 29.3.3 Predation???????? 1353 29.3.4 Resource management constraints???????? 1354 29.4 Harvesting and transporting???????? 1354 29.4.1 Methods???????? 1354 29.4.2 Marketing???????? 1355 29.5 Expected future???????? 1356 29.6 Aquaculture???????? 1357 29.6.1 Introduction???????? 1357 29.6.2 Species???????? 1358 29.6.3 History???????? 1358 29.7 Hatchery techniques???????? 1359 29.7.1 Conditioning???????? 1359 29.7.2 Induction of spawning and fertilisation???????? 1360 29.7.3 Larval culture and metamorphosis???????? 1361 29.7.4 Genetic enhancement???????? 1366 29.7.4.1 Selection???????? 1366 29.7.4.2 Crossbreeding???????? 1366 29.7.4.3 Triploidy???????? 1367 29.7.5 Antibiotics???????? 1368 29.8 Natural spat???????? 1368 29.8.1 Methods employed???????? 1368 29.8.2 Spat collection???????? 1369 29.9 Growth???????? 1372 29.9.1 Suspended cultures???????? 1372 29.9.2 Bottom cultures???????? 1375 29.9.3 Factors influencing growth???????? 1376 29.10 Mortality???????? 1377 29.10.1 Suspended culture???????? 1377 29.10.2 Bottom culture???????? 1378 29.11 Constraints???????? 1379 29.12 Future prospects???????? 1379 References???????? 1380

Chapter 30. ?Scallop Fisheries, Mariculture and Enhancement in Australia Mike Dredge

30.1 Introduction???????? 1391 30.2 History of the fisheries???????? 1392 30.3 Biology of target species???????? 1395 30.3.1 Pecten fumatus???????? 1395 30.3.1.1 Distribution and life cycle???????? 1395 30.3.1.2 Mortality???????? 1396 30.3.1.3 Monitoring, abundance and population dynamics???????? 1397 30.3.2 Amusium balloti???????? 1398 30.3.2.1 Distribution and life cycle???????? 1398 30.3.2.2 Mortality???????? 1398 30.3.2.3 Monitoring, abundance and population dynamics???????? 1399 30.4 Fisheries and their management???????? 1400 30.4.1 Pecten fumatus???????? 1400 30.4.1.1 Regulation???????? 1400 30.4.1.2 Environmental management and sustainability issues???????? 1402 30.4.2 Amusium balloti???????? 1403 30.4.2.1 Regulation???????? 1403 30.4.2.2 Environmental management and sustainability issues???????? 1404 30.5 Culture of scallops in Australia???????? 1405 30.5.1 Pecten fumatus???????? 1405 30.5.1.1 Tasmania???????? 1405 30.5.1.1.1 Spat production???????? 1405 30.5.1.1.2 Culture operations???????? 1405 30.5.1.2 Victoria???????? 1406 30.5.1.3 New South Wales???????? 1406 30.5.1.4 South Australia???????? 1407 30.5.2 Amusium balloti???????? 1407 30.6 Summary???????? 1407 Acknowledgments???????? 1408 References???????? 1408

Chapter 31. ?New Zealand Islay D. Marsden and Michael F. Bull

31.1 Introduction???????? 1413 31.2 Biology???????? 1413 31.2.1 Morphology???????? 1413 31.2.2 Distribution???????? 1413 31.2.3 Life cycle???????? 1414 31.2.4 Growth rates???????? 1415 31.2.5 Mortality???????? 1415