Fig. 11

Early metamorphosis in Schizocardium californicum. Maximum intensity projections of confocal stacks. a-g Larvae labeled with phalloidin (green), anti-acetylated tubulin antibody (red) and DAPI (blue). h-j Larvae labeled with anti-serotonin (yellow) antibodies, and DAPI (blue). All panel are anterior to the top and lateral views are ventral to the left. a Onset of metamorphosis, same stage as Fig. 10a. b Larva during early metamorphosis, same stage as Fig. 10b. The primary lobes are disappearing as the loops of the circumoral ciliary band begin to move toward each other. c Larva during mid-metamorphosis, similar stage as Fig. 10c. d-g Close-up views of coeloms and associated musculature, same individuals as panel a (f-g) and panel c (d-e). h-i Serotonergic nervous system during early metamorphosis (similar stage as panel b), showing neurites and cell bodies scattered throughout the future proboscis, collar and anterior trunk down to the telotroch. Neurite bundles are still present in the lobes and lateral grooves of the forming proboscis. j Serotonergic nervous system during early metamorphosis (similar stage as panel c). Neurite bundles are no longer present in the lobes and lateral grooves. Neurites of the anterior trunk are less abundant. A dorsal nerve tract runs along the trunk midline. cm, circular muscle fibers; dn, dorsal nerve tract; dv, dorsal view; gp, gill pore; lm, longitudinal muscle fibers; ln, lateral nerve tract; lv, lateral view; mes, mesocoel; met, metacoel; pdl, primary dorsal lobe; pds, primary dorsal saddle; pof, postoral field; prf, preoral field; pvl, primary ventral lobe; pvs, primary ventral saddle; t, telotroch; tn, telotroch nerve tract; vv, ventral view. Scale bars: 500 μm