Low magnification confocal images demonstrate dynamics of morphology and complexity during zebrafish craniofacial development. Lateral view of fli1a:EGFP zebrafish at 32 hpf (A) illustrates apparent simple and homogenous arrangement of cells in the anterior two pharyngeal arches. Lateral view of Alizarin red-stained sox9a:EGFP zebrafish at 55 hpf (B) demonstrates that most cartilages, including dorsal and ventral elements, have begun to form in these pharyngeal arches, while no bones are visible. Compared to 55 hpf, Alizarin red-stained sox9a:EGFP zebrafish by 14 dpf (C) show that cartilage elements have changed in morphology and size, but the addition of many bones results in a major increase in complexity. Abbreviations: A= anterior; ch = ceratohyal; d = dentary; dpf = days post-fertilization; hpf = hours post-fertilization; hs = hyosymplectic; Mk = Meckel’s cartilage; oe = oral ectoderm; P = posterior; pa = pharyngeal arch; pp = pharyngeal pouch; pq = palatoquadrate. Scale bars: A = 50 μm; B = 100 μm; C = 200 μm.