Fig. 1

Confocal z-projections of subsets of z-stacks of developmental stages of Carinina ochracea stained with antibodies against acetylated α-tubulin (orientation indicated by compass, apical/frontal is up, upper and lower sections omitted to make internal structures visible). a 20-hpf (17.6 µm of 54.56 µm projected) newly hatched embryo, apart from the vegetal pole the surface is uniformly ciliated. b 1-dpf (26.4 µm of 54.56 µm projected) complete gastrula, the epidermis and the blastopore are uniformly ciliated, the archenteron shows faint ciliary signals. c 3-dpf (33.44 µm of 52.8 µm projected) feeding larva, an apical tuft of elongated cilia has formed, the frontal epidermal invaginations are clearly visible. The stomodaeum shows the same ciliation as the epidermis, while the midgut cilia are less densely set. Internally the neurites of the brain ring and the ciliated nephridia are visible. Note the unspecific signals of epidermal mucus gland cells frontal of the brain ring. d 10-dpf (22 µm of 45.76 µm projected) most advanced larval stage observed, the epidermis and the stomodaeum are uniformly ciliated apart from the apical tuft of elongated cilia. The nephridia (only left side shown) and the midgut cilia appear less bright due to strong unspecific signal of the epidermal gland cells obscuring the internal structures. ap: apical, at: apical tuft, bp: blastopore, br: brain ring, do: dorsal, eci: epidermal cilia, fi: frontal epidermal invaginations, gc: mucus gland cells, l: left, mgc: midgut cilia, nep: nephridium, r: right, sto: stomodaeum, ve: ventral, vg: vegetal, vp: vegetal pole