Vertebral Development and Ossification in the Siberian Sturgeon (Acipenser Baerii), with New Insights on Bone Histology and Ultrastructure of Vertebral Elements and Scutes.

In order to improve our knowledge on the vertebral development, structure and mineralization in Acipenseriformes, we undertook a study in a growth series of reared Siberian sturgeons (Acipenser baerii) using in toto clear and stain specimens, histological and ultrastructural observations, X-ray micro-tomography, and solid state NMR analyses. Scutes were also studied to compare the tissue structure and mineralization of endoskeletal and dermal skeletal elements. This study completes and clarifies previous investigations on vertebral development and architecture in sturgeons, and brings original data on the structure of (i) the perichondral bone that is progressively deposited around the vertebral elements during ontogeny, (ii) the typical cartilage composing these elements, and (iii) the scutes. In addition we provide data on the mineralization process, on the nature of the bone mineral phase, and on the growth dynamics of the vertebral elements. Anat Rec, 300:437-449, 2017.