Figure 4

Investigated morphological features of different semaphoronts of G. falcatus (Stomatopoda) and S. ingentis (Dendrobranchiata). External morphology and developing nervous system of G. falcatus (a–d) and developing nervous system/muscular tissue of S. ingentis (e–h). (a) Semaphoront Gf EN1, showing naupliar appendage buds. (b) Same semaphoront, showing acetylated alpha-tubulin signal. Ganglion anlagen are not yet visible. (c) Semaphoront Gf V, ventral view of complete embryo, showing anlagen of all appendages. (d) Same semaphoront, developing pleon and telson anlage. Ganglion anlagen are not developed posterior to the fourth pleomeres. Continuous longitudinal neurite bundles extend into the telson. (e) S. ingentis semaphoront Si En 17. Anlagen of naupliar ganglia are present in the embryo. (f) semaphoront Si N3. The larva shows four pairs of postnaupliar appendage buds. (g) Semaphoront Si N4. Ganglion anlagen are present in the first and second maxilla segment. (g) Semaphoront Si N5. Ganglion anlagen of the first and second thoracic segments are present. (a, c) Blend projection of nuclear signal (TOPRO-3) from confocal image stack; (b) maximum intensity projection of acetylated alpha-tubulin signal; (d) extended section of acetylated alpha-tubulin (red)- and TOPRO-3-signal (blue); (e–h) extended sections of phallacidin-BODIPY-labeled specimens, with permission of Phil Hertzler. Abbreviations: BA brain anlage, Ol optic lobes, A1–P6 appendage anlagen of respective segments, T telson anlage, pc protocerebrum, dc deutocerebrum, tc tritocerebrum, md-g–P6-g ganglion anlagen of respective segments, lonb longitudinal neurite bundles, md-m medial extrinsic mandible muscle precursor, lmp longitudinal muscle precursor, P proctodeum, CP caudal papilla. Scale bars 50 μm in (a, b, e–h); 200 μm in (c), 100 μm in (d).