Preface xvii
Acknowledgements xix
Abbreviations and acronyms xxi
1 Introduction 1
Introduction 1
Reproductive modes of the teleosts 2
Gender systems of teleosts 2
Spawning dynamics 4
Modes of fertilisation 5
Mating systems 5
Secondary sexual characteristics 6
Parental care 6
Reproductive guilds 6
Reproductive diversity in teleosts: an explanatory framework 6
Phylogenetic relationships of the teleosts 8
Life-history theory 9
Aims of the volume 11
2 Sex determination 13
Introduction 13
Genotypic sex determination 14
Monofactorial genotypic sex determination 14
Multifactorial genotypic sex determination 20
Polyfactorial (polygenic) genotypic sex determination 20
Environmental sex determination 21
Evolution of sex-determining mechanisms 26
3 Sex differentiation 31
Introduction 31
Embryology of the gonads 32
Origin and migration of primordial germ cells 33
Sex differentiation in the gonadal anlagen 35
Initial differentiation of the gonads 36
Initial differentiation of ovaries 38
Initial differentiation of testes 38
Genetic control of early gonadal differentiation 40
Synthesis 42
4 Gametogenesis 45
Introduction 46
Structure of ovaries 48
Gross morphology of the ovaries 48
Development of female gonoducts 51
Oogenesis 52
Oogonial proliferation and oogonial nest formation 53
Chromatin nucleolus stage 53
Primary growth 54
Secondary growth - vitellogenesis 55
Vitellogenin and the zona pellucida proteins 56
Polarity of the oocyte 58
Oocyte maturation 58
Ovulation 60
Atresia 60
Fertilisation 62
Genetic control of oogenesis 64
Dynamics of oocyte development 65
Spawning dynamics and fecundity 66
Structure of the testes 66
Gross morphology of a testis 66
Development of male gonoducts 69
Accessory structures associated with the testes and gonoducts 70
Spermatogenesis 71
Spermatocysts 71
Sertoli cells 71
Stages of spermatogenesis within a spermatogenic spermatocyst 73
Differentiated spermatogonia 73
Primary spermatocysts 73
Secondary spermatocysts 73
Spermatids 74
Spermiation and capacitation 75
Types of spermatozoa 76
Structure and phylogenetic distribution 76
Spermatozoa viability 77
Genetic control of spermatogenesis 79
Dynamics of spermatogenesis 79
Quantitative analysis of sperm production 80
5 Endocrinology of reproduction 81
Introduction 82
Brain-pituitary-gonad reproductive axis in vertebrates 83
Levels of analysis 85
Gonadal steroids 86
Sex steroid synthesis 86
Sex steroid receptors 87
Endocrine control of oogenesis 88
Oogonial proliferation and primary growth 88
Secondary growth: vitellogenesis 89
Maturation and ovulation 90
Endocrine control of oogenesis in species with batch spawning 91
Endocrine control of spermatogenesis 93
Spermatogonial proliferation 95
Initiation of meiosis and formation of spermatocysts 95
Spermiation 96
Patterns of spawning in relation to spermatogenesis 96
The pituitary and the gonadotrophins 98
Brain-pituitary relationship 98
Gonadotrophs and gonadotrophins 99
Gonadotrophin receptors 100
Hypothalamic control of the pituitary 101
Gonadotrophin-releasing hormone 101
Functions of gonadotrophin-releasing hormone 102
Gonadotrophin-releasing hormone receptors 102
Distribution of gonadotrophin-releasing hormone neurons in the brain 103
Role of dopamine as an inhibitor of reproduction 104
Role of other brain factors in the control of gonadotrophs 105
Feedback control in the brain-pituitary-gonad reproductive axis 106
A provisional model for the control of the developmental dynamics of ovaries and testes 109
Puberty in teleosts 109
Physiological control of puberty 110
Interactions between growth and reproductive axes 113
Endocrines, behaviour and secondary sexual characteristics 116
Four model species 117
Role of endocrines in regulation of reproductive behaviour 118
Sensory systems 118
Central integrative systems 118
Motor systems 120
Endocrines and secondary sex characteristics 120
Effect of social interactions on reproductive endocrines 121
Role of pheromones in reproductive interactions 122
Endocrine-disrupting chemicals 123
Conclusions 125
6 Environmental control of reproduction 127
Introduction 128
Seasonal patterns of reproduction 128
Global seasonal patterns 128
Ultimate factors 129
Proximate factors 130
Spawning seasonality in freshwater systems 130
Spawning seasonality in marine species 132
Lunar-related reproductive cycles 134
Intertidal spawners 135
Coral reef spawners 135
Freshwater spawners 136
Diel reproductive cycles 136
Multiple environmental cycles 136
Endogenous cycles and reproductive activity 137
Proximate factors 138
Photoperiod and temperature 139
Lunar-related and tidal cycles 143
Rainfall, flooding and other cues 143
Social factors as cues 144
Stress and reproduction 144
Neuroendocrine mechanisms mediating environmental effects 147
Food as a proximate factor 150
Feeding and capital breeders 151
Feeding and income breeders 154
Feeding and skipped spawnings 155
Physiological basis for the effect of feeding on reproduction 156
Conclusions 157
7 Migration, territoriality and spawning site selection 159
Introduction 160
Migration 160
Terms and definitions 161
Migratory patterns associated with reproduction 162
Adaptive significance of reproductive migrations 164
Energetic costs of migration 166
Survival costs of migration 167
Physiological adaptations associated with migration 167
Mechanisms of orientation and homing during spawning migrations 168
Control of timing of migration 171
Human impacts on migration 172
Territoriality 173
The concept of territoriality and definitions 174
Adaptive significance of territoriality 174
Cost-benefit analysis and evolutionary stable strategy 174
Aggression and territoriality 175
Patterns of occurrence of territoriality 176
Establishment and maintenance of territories 180
Physiological basis of territoriality 182
Energetic costs of territoriality 184
Genetic basis of territoriality 184
Territoriality and population dynamics 185
Spawning site selection 188
Sites for reproduction 188
Site selection without habitat modification 188
Site preparation 189
Site excavation 189
Site preparation and young brooded elsewhere 190
Site preparation and eggs buried 191
Excavation of shelters and tunnels 192
Nest construction 193
Terrestrial spawning sites 195
Cues used in spawning site selection 197
Spawning symbioses 197
Conclusions 200
8 Mating systems and sexual selection 201
Introduction 202
Classification of mating systems 203
Sexual selection and theories of mate choice 204
Direct intersexual selection 205
Indirect intersexual selection 206
Good genes 207
Compatible genes 207
Antagonistic genes 209
Arbitrary mate choice 210
Fisherian selection 210
Sensory bias 211
Male mate choice and female ornaments 212
Mutual mate choice and the 'double process' of sexual selection 214
Mate choice copying 216
Intrasexual selection 216
The interaction of intra- and intersexual selection 218
The strength of sexual selection and the operational sex ratio 218
Courtship 219
Functions of courtship 219
Mate identification and attraction 219
Mate stimulation, mating synchrony and appeasement 220
Maintenance of pair bonds 221
Ornaments and signals in courtship 221
Visual 222
Body size 222
Morphological trait size 223
Colour 224
UV reflectance 224
Display behaviour 225
Auditory 226
Olfaction and gustation 227
Tactile, electrical and other cues 228
Multiple cues 228
Sexual signals and reproductive isolation 229
Fertilisation 231
Sperm competition 231
Cost of sperm production 231
Risk and intensity of sperm competition 232
Sperm competition avoidance 234
Pre-oviposition ejaculation 234
Seminal fluid composition 235
Sperm capacitation and motility 235
Ejaculate size and ejaculation frequency 236
External fertilisation 237
Internal fertilisation 238
Quasi-internal fertilisation 239
Male mating polymorphisms 240
Causal factors 242
Floaters, sneakers, streakers, pirates, parasites, fighters and the bourgeoisie 243
Male mating polymorphism and sperm competition 244
Guarder male response to non-guarders 244
Female response to alternative male mating phenotypes 244
Female mating polymorphisms 245
Sexual conflict 246
Phylogenetic history and mating system evolution 249
9 Parental care 251
Introduction 252
Definition of care 252
Distribution of parental care 252
Modes of parental care 253
Protection from predators and disturbance 253
Protection from hypoxia and desiccation 253
Protection from pathogens 255
Nutrition 256
External bearing 257
Internal bearing 261
Costs of parental care 262
Cost to parental survival 262
Cost to number of offspring produced 264
Sex role reversal and parental care 265
Phenotypic plasticity in care 266
Number of offspring 266
Offspring age 267
Offspring quality 267
Food availability 268
Parental age 268
Availability of alternative mates 268
Helper care systems 269
Alloparental care 270
Sneaky mating and egg dumping 270
Egg stealing, kidnapping and nest takeovers 271
Brood parasitism 271
Cooperative care 273
Misdirected care 274
Filial cannibalism 274
Evolution of parental care 276
10 Unusual reproductive modes 281
Introduction 282
Viviparity in teleosts 282
Systematic distribution of viviparity in teleosts 283
Internal fertilisation 283
Lecithotrophy and matrotrophy 286
Ovarian modifications in viviparity 287
Testis modification in viviparity 289
Gestation 289
Timing of events 289
Embryonic nutrition 290
Superfetation 291
Endocrine control of viviparity 292
Evolution of viviparity and matrotrophy 292
Male viviparity in the Syngnathidae 295
Unisexual teleosts 298
Systematic distribution of unisexual biotypes in teleosts 299
Cyprinodontiformes 300
Poeciliid unisexuals 300
Poeciliid unisexuals: Poecilia formosa 300
Poeciliid unisexuals: Poeciliopsis 300
Atheriniformes 301
Cypriniformes 301
Phoxinus eos-neogaeus 302
Tropidophoxinellus alburnoides 302
Carassius gibelio 302
Cobitis 303
Problems posed by unisexual teleosts 303
Developmental 303
Evolutionary implications 304
Hermaphroditism in teleosts 305
Phylogenetic distribution of hermaphroditism in teleosts 306
Gonadal organisation in hermaphroditic fishes 308
Endocrinology of reproduction in hermaphroditic species 309
Simultaneous hermaphrodites 312
Self-fertilisation 312
Cross-fertilisation 313
Sequential hermaphrodites 313
Protogyny 314
Protandry 315
Serial change 315
Adaptive significance of hermaphroditism 316
Why are hermaphrodites found in teleosts? 319
Deep-sea anglerfish dwarf males: quasi-hermaphroditism 320
11 Reproduction and life-history evolution 323
Introduction 324
Life-history variables 324
Size and age at maturity 325
Fecundity and clutch size 325
Egg and offspring size 327
Incubation time 331
Reproductive lifespan 333
Parental care 333
Other life-history traits 333
Basic concepts in life-history theory 334
Trade-offs 334
Costs of reproduction 334
Measuring the costs of reproduction 335
Evidence of costs of reproduction 336
Reproductive effort 338
Demographic models of life-history evolution 339
Measures of fitness 340
Predictions of demographic models 341
Empirical studies of life-history evolution 342
Habitat invasion 344
Environmental gradients 346
Habitat templet model 347
Dimensionless variables and life-history invariants 350
Plasticity of life-history traits 351
Constraints on life-history evolution 353
Alternative life-history strategies 354
Conclusions 356
12 Reproduction, fisheries and aquaculture 357
Introduction 358
Reproduction and fisheries management 358
Stock-recruitment relationships and reproduction 358
Reproductive traits and population dynamics 362
Age at maturity 362
Fecundity 363
Mode of reproduction and susceptibility to overexploitation 364
The impact of fisheries on reproductive traits 365
Age and size structure 365
Population sex ratio 368
Population size and density 370
Fisheries-induced evolution 372
Control of reproduction in aquaculture 373
Facilitating reproduction 374
Environmental manipulation 374
Endocrine manipulation 375
Sexual dysfunction in cultivated fishes 376
Sexual dysfunction in females 376
Sexual dysfunction in males 378
Preservation of gametes 378
Suppressing reproduction 379
Monosex production 379
Endocrine manipulation 380
Production of female monosex lines 381
Production of male monosex lines 382
Gynogenesis 383
Androgenesis 385
Hybridisation 385
Sterilisation 386
Mechanical, immunological, chemical and irradiation techniques 386
Hybridisation 387
Polyploidy 387
13 Coda 389
References 391
Systematic index 451
Subject index 463
