Diel Vertical Migration of Zooplankton in Lakes and Oceans (eBook)

Preface 5
Contents 8
1 Windows: An Introduction 11
1.1 Introduction 11
1.2 Individuals 12
1.3 Sensory Physiology and Behaviour 13
1.4 The Ecological Context 16
1.5 Finally 18
1.6 Notes 18
2 Swimming in a Strange Biotope 20
2.1 A Strange Environment 20
2.2 Small-Scale, Normal Swimming 22
2.2.1 The Function of Oscillating Swimming 28
2.2.2 The Mechanism at the Base of Oscillating Swimming 30
2.3 Summary 31
2.4 Notes 32
3 Light-Induced, Reactive Swimming 34
3.1 Introduction 34
3.2 The Stimulus Concept 35
3.3 Visual Thresholds 38
3.4 Reactions to Instantaneous Changes in Light Intensity 40
3.5 Reactions to Continuous Changes in Light Intensity 44
3.5.1 The Stepwise Reaction Pattern 44
3.5.2 The Stimulus Strength Duration Curve 46
3.5.3 Swimming Speed and Displacement Velocity 50
3.6 Photobehaviour in Other Planktonic Species 52
3.7 Notes 56
4 A Decision-Making Mechanism 58
4.1 Introduction 58
4.2 The Interdependence of Two Successive Stimuli 59
4.3 The Influence of Kairomone, Food and Temperature 61
4.4 Other Kinds of Experiments to Study the Role of Kairomones and Food 68
4.5 A Decision-Making Mechanism 74
4.6 Notes 78
5 Mechanistic Models 80
5.1 Introduction 80
5.2 A Model of Oscillating Swimming 84
5.3 The Photobehaviour Model 88
5.4 The DVM Model 95
5.5 Notes 100
5.5 Appendix: The Used Model (Stella Software, Research 1996, High Performance Systems, Inc.) 101
5.4.0 Photobehaviour Model with Oscillating Swimming 105
5.4.0 DVM Model 109
6 Light and Temperature 113
6.1 Introduction: The Relevance of Biological Factors 113
6.2 Physical Aspects of Light in Water 114
6.2.1 The Air--Water Interface 115
6.2.2 The Angular Light Distribution (ALD) 117
6.2.3 Downwelling Light Attenuation 118
6.2.4 Ultraviolet Radiation 121
6.3 The Biological Factor Light 124
6.4 Temperature 130
6.5 Notes 135
7 Optical Orientations 137
7.1 Introduction 137
7.2 The Structure of Optical Sense Organs of Cladocerans and Copepods 139
7.2.1 The Compound Eye of Daphnia 139
7.2.2 The Nauplius Eye 144
7.3 The Orientation of Daphnia in the Vertical Plane 146
7.3.1 Pinned Animals 146
7.3.2 Free-Swimming Daphnia 149
7.3.3 The Mechanism of Contrast Orientation 151
7.4 Optical Orientation in Other Planktonic Animals 157
7.5 Notes 164
8 Considerations Before Going into the Field 167
8.1 General Introduction 167
8.2 Notes 176
9 Diel Vertical Migration in Lakes 177
9.1 Introduction 177
9.2 The Seasonal Character of Migration 178
9.2.1 A Natural Experiment 181
9.2.2 The Beginning of the Period of Diel Vertical Migration 186
9.2.3 The Development of the Migration Amplitude 190
9.3 Diel Vertical Migration Caused by UV Radiation 196
9.3.1 The Damaging Effects of Ultraviolet Radiation 197
9.3.2 Induced Migrations 202
9.4 The Influence of Food 207
9.5 Complications 210
9.5.1 Reverse Migrations 211
9.5.2 Drifts 214
9.6 Interpretations 216
9.7 Notes 218
10 Migrations in the Marine Environment 222
10.1 Introduction 222
10.2 Some Interesting Problems 225
10.2.1 Ontogenetic Differences 225
10.2.2 A Disguished Optimum 227
10.2.3 Metabolic Advantage Revisited 228
10.3 Interesting Copepods in Dabob Bay 229
10.4 Krill 238
10.5 Sound Scattering Layers (SSL) 247
10.6 Notes 251
11 The Confrontation of Experimental and Field Studies 255
11.1 Introduction 255
11.2 Three Examples from Very Different Species 257
11.2.1 Phantom Larvae 258
11.2.2 Daphnia 261
11.2.3 Sound Scattering Layers (SSL) 265
11.3 Special Circumstances 267
11.3.1 Polar Regions 267
11.3.2 Solar Eclipses 271
11.4 Nymphs on Drift 273
11.5 Notes 276
12 From the Individual to the Population and Beyond 277
12.1 Introduction 277
12.2 Changes in Population Size During Periods of Migration 278
12.2.1 Two Examples of Population Dynamics 281
12.3 Quantifying 0+Fish Populations 284
12.3.1 Catching 0+Perch 286
12.3.2 Times of Feeding and Food Composition 290
12.4 Comparing a Year with a Weak and a Strong Migration 294
12.5 The Relevance of Life-History Experiments 301
12.6 Complications Again: Genetic Differences 304
12.7 Notes 308
12.7 Appendix 308
13 Recapitulations and Considerations 310
13.1 The Importance of Studies of Behaviour 310
13.2 Behaviour in Marine and Freshwater Biotopes Is Comparable 313
13.3 Ontogenetic Developments 314
13.4 Notes on the Chemical Nature of Infochemicals 316
13.5 Information Exchanges 317
13.6 Infochemicals and the Pelagic Food Web 319
13.7 Finally 322
13.8 Note 323
References 324
Index 350