Figure 4 in Five invaginations and shedding of the larval epidermis during development of the hoplonemertean Pantinonemertes californiensis (Nemertea: Hoplonemertea)

Figure 4. Confocal micrographs of phalloidin-labelled early rudiment stage Pantinonemertes californiensis larvae. (A, C, D) Three-day-old larvae (12–13◦C); (B) 2-day-old larva (15–16◦C); apical pole up, ventral to the left in (A, C, D). (A) Lateral view, showing apical plate (ap) and the two shallow dimples at the anterior end – remnants of one of the anterior invaginations (ai1 and ai2); (B) a 15-µm frontal sub-stack showing the two forks of anterior invaginations (ai1 and ai2), the remnants of posterior invaginations (pi∗), posterior cirrus (pc) and midgut lumen (arrowhead); (C) a single sagittal 1-µm section showing the cerebral ganglia (cg) and lateral nerve cord (lnc); (D) same embryo as in (C), different 1-µm section showing the proboscis (pb), dorsal commissure (dc), and ventral commissure (vc) of the brain.