Fig. 6
Development of the ciliary bands in the pilidium nielseni of Micrura sp. “dark.” Confocal z-projections of 3–5 day old larvae stained with phalloidin, and oriented with the apical plate up. Ciliary bands are marked by arrowheads. a. A slightly oblique lateral-vegetal view showing the “pileus” stage (3-day old). Anterior lobe (al) left and posterior lobe (pl) right. Posterior lobe can be identified by the position of the larval cirrus (lc). Shows the two separate segments of the future “telotroch” spanning the two lateral lappets (lp1, lp2) and the two segments of the future “prototroch” (arrowheads) spanning the larval lobes (lb). Blastopore is marked with an asterisk. b. Lateral view of a larva at the “pileus” stage. Shows the lateral gap between the two segments of the future “prototroch.” c. Lateral view of a larva several hours past the “pileus” stage. Shows the two “prototroch” segments (arrowheads) making contact. d. Frontal view of a larva several hours following the “pileus” stage, showing the formation of the complete “telotroch” as the ciliary bands spanning the lappets (lp) make contact. Scale bars 50 μm