Ecophysiology of Amphibians Inhabiting Xeric Environments

1 Introduction.- 2 Xeric Habitats and Their Amphibian Inhabitants.- 2.1 The Habitats.- 2.1.1 The Xeric Habitat.- 2.1.2 The Semi-arid and Arid Habitats.- 3 Structural and Functional Adaptations of Key Organs...- 3.1 Structure and Function of the Integument.- 3.1.1 The Epidermal Structure of Amphibians Inhabiting Xeric Environments.- 3.1.1.1 The Epidermis Structure of the Anuran (Pelobates) Tadpole.- 3.1.1.2 The Epidermis Structure of the Anuran (Pelobates), Post-metamorphic, Terrestrial Stage...- 3.1.1.3 Epidermal Thickness.- 3.1.1.4 Other Anurans Inhabiting Xeric Environments...- 3.1.1.5 Cell Dynamics.- 3.1.1.6 The Epidermis of the Urodele Salamandra salamandra, Aquatic Stage.- 3.1.1.7 Specialized Cell Types of the Urodelan (Salamandra) Larva.- 3.1.1.8 The Urodelan Leydig Cell.- 3.1.1.9 The Larval Mitochondria-Rich Cell, MRC.- 3.1.1.10 The Epidermis of the Urodelan (S. salamandra), Terrestrial, Post-metamorphic Stages.- 3.1.1.11 The Flask Cell.- 3.1.1.12 Conclusions.- 3.1.1.13 Epidermal Cell Layers.- 3.1.1.14 Epidermal Cell Diversity.- 3.1.1.15 The Leydig Cell of Larval Urodeles.- 3.1.1.16 S. salamandra Larval MRC and the Flask Cells of the Adult.- 3.1.2 The Dermis.- 3.1.2.1. The Anuran Calcified Dermal Layer.- 3.1.2.2 Dermal Glands.- 3.1.2.3 Chromatophores.- 3.1.3 Moulting.- 3.1.4 Cocoons.- 3.1.5 Transport of Ions Across the Skin.- 3.1.6 Water Movement Across the Skin.- 3.1.7 Nitrogen Excretion Across the Skin.- 3.1.8 Conclusions.- 3.2 Respiratory Organs and Respiration.- 3.2.1 Structure and Function of the Gills.- 3.2.1.1 The Gill Integument of Salamandra Larvae.- 3.2.1.2 Specialized Cells in the Salamander Gill Integument.- 3.2.2 Structure of the Lungs and Respiration.- 3.2.2.1 Structure.- 3.2.2.2 Respiration.- 3.3 The Endolymphatic System as Calcium Reserve.- 3.4 Kidney Structure and Function.- 3.4.1.1 Kidney Structure.- 3.4.1.2 Kidney Function.- 3.4.2 Endocrine Control of Excretion.- 3.4.3 The Urinary Bladder.- 3.5 Structure and Function of the Female Reproductive System.- 3.5.1 The Ovary and Oogenesis.- 3.5.1.1 Oogenesis.- 3.5.2 Mating, Sperm Storage, Fertilization and Gestation.- 3.5.3 Conclusions.- 4 Receptors, Perception and Behavioural Responses.- 4.1 Photoreception and the Response to Light.- 4.2 Acoustic Behaviour.- 4.3 Olfaction.- 4.4 Selection of Suitable Substrate Moisture and pH..- 4.5 Feeding Behaviour.- 4.6 Locomotory Rhythms and Activity Patterns.- 4.7 Orientation, Homing and Migration.- 4.7.1 Orientation.- 4.7.2 Homing.- 4.7.3 Migration and Breeding Behaviour.- 4.8 Social Behaviour.- 4.8.1 Aggregation Behaviour.- 4.8.2 Kin Recognition.- 4.9 Endocrine Control of Behaviour.- 4.9.1 The Pineal Gland.- 4.9.2 Courtship and Mating Behaviour and Their Endocrine Control.- 4.10 Learning.- 4.11 Conclusions.- 5 Physiological Adaptations.- 5.1 Water Balance.- 5.1.1 Water Content.- 5.1.2 Remarks about Techniques.- 5.1.3 Evaporative Water Loss.- 5.1.4 Survival of Dehydration.- 5.1.5 Water Uptake.- 5.2 Body Fluid Osmolality and Ion Concentration….- 5.3 Nitrogen Balance.- 5.3.1 Ureotelic Amphibians and Urea Retention.- 5.3.2 Uricotelic Amphibians.- 5.3.3 Other Forms of Nitrogen Excretion.- 5.4 Endocrine Control of Water, Electrolyte and Nitrogen Balance.- 5.4.1 Endocrine Control.- 5.4.1.1 The Neurohypophysial Hormones.- 5.4.1.2 The Adenohypophysial Hormones Prolactin (PRL).- 5.4.1.3 The Thyroid Hormones.- 5.4.1.4 Corticosteroids and the Interrenal Hormones….- 5.4.1.5 Parathyroid and Ultimobranchial Hormones Regulating Calcium Balance.- 5.4.1.6 Atrial Natriuretic Peptides (ANP).- 5.4.1.7 Conclusions.- 5.5 Thermal Balance.- 5.5.1 Temperature Preferences.- 5.5.2 Body Temperature Regulation at High Temperatures.- 5.5.3 Critical Thermal Maximum.- 5.5.4 Development Rate and Survival Time at High Temperature.- 6 Ecological Adaptations.- 6.1 The Aquatic Environment.- 6.1.1 Breeding Modes.- 6.1.2 Reproductive Season, Onset and Duration.- 6.1.3 Breeding Migration.- 6.1.4 Batch or Brood Size 1ll.- 6.1.5 Development and Metamorphosis 1ll.- 6.1.6 Development Time.- 6.1.7 Larval Competition for Food Resources, Carnivory, Prédation and Cannibalism.- 6.1.8 Survival of Larvae.- 6.1.9 Factors Affecting Success of Metamorphosis.- 6.1.10 Reproductive Strategies.- 6.1.11 Habitat Use.- 6.2 The Terrestrial Amphibian.- 6.2.1 Aquatic Phase of the Adult Amphibia Inhabiting Xeric Habitats.- 6.2.1.1 The Paedomorphic Amphibian.- 6.2.2 The Adult Terrestrial Amphibian Inhabiting Xeric Habitats.- 6.2.2.1 Ecological Problems with Breeding.- 6.2.2.2 Role of Climate in the Survival of Juveniles and Adults.- 6.2.2.3 Population Ecology of Amphibians Living in Xeric Habitats.- 6.2.2.4 Longevity.- 6.2.2.5 Density Effects.- 6.2.2.6 Climatic Effects.- 6.2.2.7 Population Cycles.- 6.2.2.8 Population Explosion and Migration.- 6.2.2.9 Amphibian Communities.- 6.2.2.10 Conclusions.- 7 Reflections and Conclusions.- 7.1 Habitat.- 7.2 Structure and Function.- 7.3 Behavioural Responses.- 7.4 Ecological Adaptations.- 7.4.1 Breeding and Larval Stages.- 7.4.2 Longevity.- References.