FishFace

By 55 hpf, developing cartilage cells of the craniofacial skeleton are apparent in discrete cartilage elements, such as the trabecula (t) and the ethmoid (e) of the neurocranium, Meckel’s cartilage (Mk); and the palatoquadrate (pq), which are derived from the first pharyngeal arch, and the ceratohyal (ch) and the hyosymplectic (hs), which are derived from the second pharyngeal arch. All of these cartilage cells are surrounded by a secreted cartilage matrix at this timepoint (data not shown).