Goldfish Development and Evolution

This book explains how the beautiful goldfish body develops from a single fertilized egg and how this developmental process was changed during the process of domestication. The contents can be categorized as follows: i) numerous high-quality live photo images of embryonic and larval stage goldfish, ii) detailed descriptions of skeletogenesis with fluorescent microscopic and histological images, iii) the most advanced interpretation of the relationship between artificial selection and developmental processes, iv) future perspectives of the application of the genome editing techniques for the ornamental goldfish breeding, and v) methodological descriptions for goldfish developmental biology. Goldfish is a popular ornamental domesticated fish species, and its highly diverged morphological features and color variations attract fanciers. The goldfish has been spread all over the world by breeders, and this fish has also been employed as an experimental organism by researchers in the field of life science. However, so far, no available scientific books provide a detailed description of the embryogenesis and morphogenesis of this animal. Compared with the number of published fancier books, the number of books on goldfish biology is very few. This publication will be useful not only for the research community particularly in the fields of developmental biology, evolutionary biology, zoology, aquaculture, fishery science, and related areas but also for enthusiastic goldfish fanciers and breeders. Preface Acknowledgments Contents Abbreviations Chapter 1: Introduction 1.1 Goldfish Developmental Biology According to Early Researchers of Evolution 1.2 Early Research on Goldfish Domestication 1.3 Pre-domestication to Domestication 1.4 Domestication for Ornamental Purposes 1.5 Selection of Peculiar Morphologies References Chapter 2: Goldfish as an Experimental Model 2.1 Phylogenic Position Among Vertebrates 2.2 Problems with Nomenclature, Phylogeny, and Biogeography 2.3 Duplicated Goldfish Genome 2.4 Low Oxygen Tolerance, Physiology, and Neuroscience 2.5 Rise and Fade of Goldfish Embryology 2.6 Contrast Between Zebrafish Mutants and Goldfish Strains 2.7 Comparison with Other Domesticated Animals References Chapter 3: Varieties of Goldfish Morphology 3.1 The Single-Tail Common Goldfish as the ``Wild-Type ́ ́ Goldfish 3.2 Overview of the Wild-Type Goldfish Morphology 3.3 Mutated Morphological Features 3.3.1 Nomenclature of Ornamental Goldfish Strains 3.3.2 Cranial Level 3.3.3 Trunk Level 3.3.4 Pectoral Fin 3.3.5 Pelvic Fin 3.3.6 Dorsal Fin 3.3.7 Anal Fin 3.3.8 Caudal Fin 3.3.9 Integuments 3.4 Responsible Loci 3.5 Three Representative Morphotypes 3.5.1 Single-Tail Morphotype 3.5.2 Twin-Tail Morphotype 3.5.3 Dorsal-Finless Morphotype 3.6 Descriptions of Intermediated Morphotypes 3.6.1 Variations of Caudal and Anal Fin Mutations 3.6.2 Variations in Dorsal-Finless Mutants 3.7 Cataloging of Goldfish Morphological Variations References Chapter 4: Development of the Wild-Type Goldfish 4.1 Normal Developmental Staging Table for Goldfish 4.2 Embryonic Development of the Single-Tail Common Goldfish 4.2.1 Zygote to Blastula Periods 4.2.1.1 One-Cell Stage 4.2.1.2 Cleavage Period (2-Cell to 64-Cell Stages) 4.2.1.3 Blastula Period (128-Cell to Early Epiboly Stages) 4.2.2 Gastrula Period (50% Epiboly to Bud Stages) 4.2.2.1 50% Epiboly 4.2.2.2 Germ Ring 4.2.2.3 Shield 4.2.2.4 25% bc 4.2.2.5 80% bc 4.2.2.6 85% bc 4.2.2.7 Bud 4.2.2.8 Note on the Active Movement of Yolk and Staging of the Late Gastrula Stage 4.2.3 Segmentation Period (6-22 Somite Stages) 4.2.3.1 6-Somite Stage 4.2.3.2 10-Somite Stage 4.2.3.3 14-Somite Stage 4.2.3.4 18-Somite Stage 4.2.3.5 22-Somite Stage 4.2.4 Pharyngula Period (25-65% OVC) 4.2.4.1 25% OVC 4.2.4.2 35% OVC 4.2.4.3 65% OVC 4.2.5 Hatching Period (Long-Pec to Protruding-Mouth) 4.2.5.1 Long Pec 4.2.5.2 Pec Fin 4.2.5.3 Protruding Mouth (Prot) 4.3 Post-embryonic Developmental Process 4.3.1 Larval Period 4.3.1.1 Prot Stage 4.3.1.2 Psb 4.3.1.3 Cr 4.3.1.4 Fcf 4.3.1.5 Asb 4.3.1.6 Dr 4.3.1.7 Ar 4.3.1.8 Pb 4.3.1.9 Pr 4.3.2 Juvenile 4.3.2.1 IsJ Sub-stage 4.3.2.2 CsJ Sub-stage 4.3.3 Adult 4.4 Development of the Skeletal System 4.4.1 Cranial Region 4.4.2 Mid-Trunk Skeleton 4.4.3 Pectoral Fin Skeleton 4.4.4 Pelvic Fin Skeleton 4.4.5 Dorsal Fin Skeleton 4.4.6 Anal Fin Skeletons 4.4.7 Caudal Fin Skeleton 4.5 Notable Similarities/Differences Between Goldfish and Zebrafish References Chapter 5: Development of Mutant Goldfish Strains 5.1 Twin-Tail Morphotypes 5.1.1 Staging Indexes and Rates of Embryo Development 5.1.2 Early Embryogenesis of the Twin-Tail Morphotype 5.1.3 Modified Dorsal-Ventral Patterning 5.1.4 Twin-Tail Morphotype-Specific Features at Late Embryonic and Early Larval Stages 5.1.5 Skeletal Development During Larval Periods 5.1.5.1 Prot Stage 5.1.5.2 Psb Stage 5.1.5.3 Cr Stage 5.1.5.4 Fcf Stage 5.1.5.5 Asb Stage 5.1.5.6 Dr Stage 5.1.5.7 Ar Stage 5.1.5.8 Pb Stage 5.1.5.9 Pr Stage 5.1.6 Histology of Larvae at the Trunk Level 5.1.7 Comparison of Axial Skeletal Development in Larvae 5.1.8 Juvenile and Adult Stages 5.1.9 Inter- and Intra-strain Variations of the Developmental Process 5.2 Dorsal-Finless Morphotype 5.2.1 Pharyngula Stage Embryos and Hatching Stage Larvae 5.2.2 5-9 dpf Larval Progenies 5.2.3 Limitations of Staging Indexes for the Dorsal-Finless Morphotype 5.2.4 Molecular Interpretation of the Developmental Process 5.3 Notes on the Cranial Level, Body Shape, and Integument Ornamental Phenotypes 5.3.1 Telescope Eyes 5.3.2 Warty Growth 5.3.3 General Ornamental Mutant Phenotypes at the Cranial Level 5.3.4 Globular Body Shape 5.4 Genes and Development References Chapter 6: Evodevo Questions Related to Ornamental Morphology 6.1 Bifurcated Median Fin Mutations of Twin-Tail Morphotype Goldfish 6.1.1 Chordin Paralogs and Their Expression Patterns 6.1.2 Absence of the ``Twin-Tail Common Carp ́ ́ 6.1.3 Implications for Required Conditions for Large-Scale Morphological Evolution 6.1.4 Independent Development of Paired Fins and Bifurcated Median Fins 6.1.5 Divergence of the chdL Paralog 6.1.6 Bifurcated Caudal Fin Resulting from Other Mutations 6.1.7 Other Dorsal-Ventral Patterning-Related Genes 6.2 Dorsal-Finless Morphotype and Its Deviated Morphology 6.2.1 Dorsal-Finless Phenotype with Different Gene Mutations 6.2.2 Relationship with the Twin-Tail Morphology 6.3 Absence of ``Mirror Scale Goldfish ́ ́ 6.4 Different Ways to the Globular Body Shape 6.5 Differences in Developmental Timings Between Mutated Phenotypes References Chapter 7: Problems, Challenges, and Perspectives 7.1 Fixable Mutations Through Developmental Process 7.2 Genotype and Phenotype 7.3 Homozygosity, Development, Environment, and Polymorphisms 7.4 Perturbations, Development, and Evolution 7.5 Novel Phenotype and Developmental Process 7.6 Genome Editing-Derived Domestication References Chapter 8: Experimental Notes 8.1 Parents 8.1.1 Obtaining Parental Goldfish 8.1.2 Size of Adult Goldfish 8.1.3 Identification of Individual Live Goldfish 8.1.4 Sexing in Spawning Season 8.2 Live Feed 8.3 Artificial Fertilization 8.3.1 Preparation of Parent Fish 8.3.2 Hormone Stimulation 8.3.3 Preservation of Sperm 8.3.4 A Note on Over-matured Eggs 8.3.5 Dry Method of Insemination 8.3.6 Blocking of the Bottom of the Polystyrene Plastic Dish (Optional) 8.3.7 Washing Fertilized Eggs 8.4 Embryo and Juvenile Nursery 8.4.1 Incubation Condition 8.4.2 Counting Live and Dead Eggs 8.4.3 Maintenance of Larvae 8.4.4 Growth of Goldfish as Next Generation Parents 8.5 Conventional Stereomicroscopic Observations 8.5.1 Detaching Eggs from the Dish and Dechorinoization 8.5.2 Light Microscopic Observation of Live Embryos, Larvae, and Juveniles 8.5.3 Observation of Skeletons 8.6 Conventional Histological Observation 8.6.1 Fixation Process 8.6.2 Paraffin Embedding and Sectioning 8.6.3 Staining and Identification of Sectioned Level 8.7 Genotyping Analysis 8.7.1 DNA Extraction 8.7.2 PCR-Based Genotyping of the Twin-Tail Gene (chdSE127X) 8.8 Analysis of Gene Expression Patterns 8.8.1 Complementary DNA (cDNA) Cloning and Sequence 8.8.2 Digoxigenin (DIG)-Labeled Antisense RNA Probe Synthetize 8.8.3 Harvesting and Fixation of Samples 8.8.4 Hybridization, Detection of Signals, and Image Acquisition 8.9 Functional Assays of Genes 8.9.1 General Methods for Microinjection 8.9.2 Morpholinos 8.9.3 Synthesized mRNA References Index