Posterior ciliary belts of the
larva. Bottom views of developing larvae showing the changing region of the future pygidium. Nuclei are stained with DAPI (grey) and cilia with an anti-acetylated tubulin antibody. Views are 3D renderings of confocal stacks of images, made with Image J. The telotroch cilia have been false-colored in green whereas prototroch and paratroch cilia are colored in red. A: schematic representation of the perspective chosen for the 3D rendering, the presumptive pygidial territory is colored in cyan. B-D: 3D reconstructions of larvae at 30, 48 and 60 hpf, respectively. The presumptive pygidium is delineated with blue dashed lines. pr – prototroch; p2 and p3 – paratrochs of the second and third chaetigerous segments respectively; tt – telotroch; st – stomodeum; cp – pygidial cirri.