Reproductive Biology of Fishes

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