Figure 6

Investigated morphological features of different semaphoronts of P. fallax forma virginalis (Pleocyemata). Developing nervous system of P. fallax forma virginalis. (a) Semaphoront Pf I, ventral view of embryo. The naupliar ganglia are present, as well as posterior pioneer neurons [NGA], [PPN]. Appendage anlagen of the first antennal to the second thoracic segments are present. (b) Semaphoront Pf III, pleon and telson anlage. Ganglion anlagen are observed in none of the pleonal segments, but continuous longitudinal neurite bundles extend anteriorly from the posterior pioneer neurons. (c) Semaphoront Pf As8, posterior pleon and telson anlage. Developing ganglia are observed in all pleomeres, including the sixth pleomere [p6-g]. All panels show maximum intensity projections of acetylated alpha-tubulin signal (red) and nuclear signal (TOPRO-3), (blue), from confocal image stacks. In (a–c), appendage anlagen are demarcated with dotted lines. Abbreviations: 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, CP caudal papilla. Scale bars 100 μm in all panels.