Fig. 4

ARS staining of fixed zebrafish samples. Panels a-b show a vertebral column of a 10 dpf larva stained with 0.01 % ARS in 70 % ethanol. a Bright field observation provides less detail of the early mineralization deposits than b fluorescence observation (arrowheads). Panels c-d show cranial structures of a juvenile (30 dpf, 8 mm TL) stained with 0.01 % ARS and observed under c bright field and d fluorescent light, evidencing the higher power of detection of, e.g., the operculum (arrowheads) under fluorescent conditions. Scale bars (a, b) = 0.04 mm; (c, d) = 0.2 mm