ABSTRACT
This chapter aims to describe and discuss the roles of Chondrichthyes models in science and how this group has contributed to the field of experimental biology. The authors discuss the ways in which this diverse class of cartilaginous fish has had a historical position in the development of experimental biology (embryology, developmental biology). Current trends in Chondrichthyes science are detailed, as different species have helped develop specific research topics. Chondrichthyan models are described in terms of life cycles, embryogenesis, anatomy and genomic data. Descriptive and functional approaches that have been successfully tested on Chondrichthyes models are presented. Finally, challenging questions in biomedical research on Chondrichthyes biomolecules as well as evo-devo research topics are addressed. Chondrichthyes are the sister group of Osteichthyes, and this phylogenetic position makes them excellent models to understand how developmental processes have changed during the evolution of vertebrates. Additionally, because of the ecological niches they occupy, they have intrinsic properties that are unique and that may be valuable for biomedical research, for example.
