The acquisition of fundamental information by the use of recent technologies, including omics-based molecular analyses and total RNA sequencing, has opened the door to further advances in physiological studies on new animal models. Currently, we are endeavoring to develop a comparative hematology protocol in order to build a discovery platform. All vertebrates, with the exception of a few species, have universally peripheral erythrocytes and hemoglobin, suggesting erythropoiesis to be an evolutionary index.