Fig. 12.

Neurogenesis in female Dinophilus gyrociliatus (a-e) and D. taeniatus (f-k) as revealed by FMRFamide-LIR. FMRFamide-like immunoreactive elements shown as white structures on black background, animals are oriented with the anterior end up. 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 FMRFamide-like immunoreactive nervous system in early embryos of D. gyrociliatus with a detail of the first immunoreactive cell, b detail of the brain and anterior nervous system in a hatching female, c detail of the anterior trunk nervous system in an early juvenile female, d nerve ring around the midgut-hindgut-transition in a juvenile female, e ventral view of the FMRFamide-like immunoreactive nervous system in an adult female with detail of the nerve ring around the midgut-hindgut-transition, f ventral view of an embryo at ventral ciliary field stage of D. taeniatus with two immunoreactive cells with a process in the head region with a detail of these cells, g lateral view of a late embryo with multiple FMRFamide-like immunoreactive perikarya surrounding the neuropil and throughout the ventral nervous system, h dorsal view of a late embryo, i ventral view of a juvenile specimen j ventral view of an adult, k dorsal view of an adult. Abbreviations: acom – anterior commissure, cec – circumesophageal connective, cfhg – connection between the FMRFamide-like immunoreactive nervous ring around the midgut-hindgut-transition and the ventrolateral nerve cords, cmvn – circumesophageal commissure forming the medioventral nerve, com1-6 – commissure 1–6, cvln – circumesophageal commissure forming the ventrolateral nerve cord, fhg – FMRFamide-like immunoreactive ring around the midgut-hindgut transition, fp – FMRFamide-like immunoreactive perikaryon, fpbr – FMRFamide-like immunoreactive perikarya of the brain, fphg – FMRFamide-like immunoreactive perikaryon associated with the ring around the midgut-hindgut transition, fpl – FMRFamide-like immunoreactive plexus in the neuropil, fpst – FMRFamide-like immunoreactive perikaryon of the stomatogastric nerve ring, lpn – longitudinal peripheral nerve, mcom – median commissure, mo – mouth opening, mvn – medioventral nerve, nar – nerves innervating the anterior rim, pcom – posterior commissure, tcom – terminal commissure, vlnc – ventrolateral nerve cord