Fig. 7. Propidium iodide stained sagittal sections through trunk muscles of larval zebrafish, aged 16 (A,B), 18 (C,D), 24 (E,F) and 72 h.p.f. (G,H). For each stage, two sections are shown, one close to the medial plane and one at a more lateral position. Hs, horizontal septum; m, myoseptum; nc, notochord; nt, neural tube. Horizontal scale bars, 20 µm.