Characteristics of the stomatogastric ganglion supplying the oesophagus and midgut in the tardigrade Macrobiotus cf. <i>harmsworthi</i>.

<p>Projections of confocal z-series. (A) Anterior half of a specimen in dorsal view. Anti-serotonin immunolabelling. Maximum projection of a confocal z-series. Note serotonin-like immunoreactivity in the stomatogastric ganglion. Arrowheads point to three posterior neurites. (B) Detail of the stomatogastric ganglion. Combined anti-tyrosinated and anti-acetylated α-tubulin immunolabelling. Neuronal cell bodies are marked by asterisks. (C) Detail of a lateral posterior neurite (arrowhead), which has an input into the second trunk ganglion (arrow). Anti-serotonin immunolabelling. Projection of a confocal z-series. Abbreviations: br, position of the brain; cn, connective; en, oesophageal neurite; ex, somata of extra-cerebral neurons innervating the mouth cone; ga1–ga2, position of the first and second trunk ganglia; lp, lateral neurite; mc, mouth cone; pp, posterior neurite; sg, stomatogastric ganglion; so, neuronal somata; un, unpaired posterior neurite/nerve. Scale bars: 10 µm (A–C).