Changes in juvenile sturgeon erythrocytes across age classes reflects evolutionary development

Erythrocytes are important for gas transport and exchange in animals and play an important role in maintaining normal functions of the body. The purpose of this study was to observe the changes in erythrocyte morphology during the development of juvenile sturgeon (Acipenser baeri ♀×Acipenser schrenckii ♂ hybrid F1) and to describe the relationship between erythrocyte morphology and development. We compared the erythrocyte morphology of juvenile sturgeon in three developmental stages. The results showed that the blood index of the sturgeon in different age classes was significantly different. The erythrocyte volume in the blood became smaller and the shape of erythrocytes changed from circular to elliptical. With the increase in age, the number of self-dividing erythrocytes, and the types and numbers of organelles in the erythrocytes, decreased. The results demonstrated that the morphology and the internal structure of erythrocytes develop to be more beneficial for gas transport reflecting the needs for juvenile sturgeon maintenance and environmental changes.