Development of Marine Fish: Several Procedures for the Observation of Embryonic Development

The technologies of developmental biology have been improving over the past 30 years. Full genome sequencing enables between species comparisons, and genomics have revealed continuous genetic relationships between species. Genetic manipulation, such as modification of specific genes and genetic improvements, has been getting easier by gene editing technology, if fresh fertilized fish eggs are prepared and cultured. On the other hand, micro-manipulation, such as micro-operation of embryos, also opens a new possibility of surrogate production. Gametes have been induced through germ-line chimera induced artificially by germ-cell transplantation between different species. In this context, the intercellular interaction between species with different genomes is an important subject to be analyzed. In this section, general methods are described for artificial fertilization and cultivation in teleosts, and a few methods useful for experimental embryology are introduced. Then, observation procedures and development are described in several species. Finally, some experiments are introduced to study embryonic mechanisms in freshwater species. These experiments may be possible in other species if chorion can be removed at the early embryonic stage.