Fig. 2

Myogenesis in Dinophilus gyrociliatus females. Phalloidin-labelled actin-filaments shown in green, labelling of DNA with DAPI shown in blue, animals are oriented with the anterior end up (a-e, g, h) or to the left (f). Stages are indicated by silhouettes next to the figure capture, and the assignment to the respective stage next to them. The first signs of difference between the two species D. gyrociliatus and D. taeniatus are emphasized by a yellow dashed-lined frame around the picture. a Ventral view of the onset of myogenesis in the early embryo (3 days after the egg is deposited), b Ventral view of the female D. gyrociliatus with ventrolateral and dorsolateral longitudinal muscles developed in the early embryo (3.5–4 days after the egg is deposited), c ventral view of the exogastrically curled females in the late embryo (5–5.5 days after the egg is deposited), d prehatching females (left female still curled exogastrically inside the egg layer, right female free inside the cocoon with the dorsolateral side up, 5.5–6 days after the egg is deposited), e dorsal view of the head musculature in an early juvenile female, f dorsoventral view of the trunk musculature with longitudinal, circular and diagonal elements in an early juvenile female, g ventral view of the head musculature in an adult female, h lateral view of the posterior region of an adult female. Abbreviations: cb1-2 –ciliary band 1–2, cm – circular muscle, cmds – circular muscle of the digestive system, dlca – contralatero-anterior branch of the dorsolateral longitudinal muscle, dlcb – contralateral branch of the dorsolateral longitudinal muscle, dldb – dorsal branch of the dorsolateral longitudinal muscle, dlia – ipsilatero-anterior branch of the dorsolateral longitudinal muscle, dlib – ipsilateral branch of the dorsolateral longitudinal muscle, dllm – dorsolateral longitudinal muscle, dlvb – ventral branch of the dorsolateral longitudinal muscle, dm – diagonal muscle, lmds – longitudinal muscle of the digestive system, mo – mouth opening, mrmo – muscular ring around the mouth opening, np – neuropil, phb – pharyngeal bulb, phm – pharyngeal muscle, pyg – pygidium, sm – sigmoid muscle, vca - contralatero-anterior branch of the ventral longitudinal muscle, vcf – ventral ciliary field, vlcb – contralateral branch of the ventrolateral longitudinal muscle, vldb – contralatero-dorsal branch of the ventrolateral longitudinal muscle, vldb – dorsal branch of the ventrolateral longitudinal muscle, vlib – ipsilatero-anterior branch of the ventrolateral longitudinal muscle, vllm – ventrolateral longitudinal muscle, vlm – ventral longitudinal muscle, vlvb – ventral branch of the ventrolateral longitudinal muscle