Fig. 12

Chondrification of the cranial skeleton in A. burtoni. Chondrified elements of the cranio-facial skeleton are detected using staining with Alcian blue. At 3 dpf, no chondrogenic differentiation of the craniofacial skeleton is yet detected At 4 dpf, the first elements corresponding to the pharyngeal skeleton become vissible and differentiate rapidly, so that at 5 dpf, the full complement of pharyngeal cartilages has formed. The schematic illustration of the chondrogenic cartilages present is for 6 dpf. Abbreviations: dpf: days post fertilization