Fig. 1

HA-like elements in palps and prostomium of Pygospio elegans. a, b HA-like elements in distal (a) and middle (b) parts of the palp. Yellow arrows label receptor cells. c High magnification of HA-positive palp receptor cells. d – f Partial z-projections through the cerebral ganglion in dorsoventral direction. HA-positive cell somata are labeled by yellow arrowheads. Abbreviations: dc – dorsal cerebral commissure, drcc – dorsal roots of the circumesophageal connectives, fpn – frontal posterior nerves, nn – nuchal nerve, no – nuchal organs, pln – palp nerve, vc – ventral cerebral commissure, vrcc – ventral root of circumesophageal commissure. HA-like elements – cyan to white, acetylated α-tubulin-like elements – magenta