Fig. 1

Schematic drawings of female Osedax mucofloris nervous system, based upon immunohistochemical studies. a Drawing of the nervous system visualized with acetylated α-tubulin IR in CLSM (entire nervous cytoskeleton). b Drawing of the serotonin LIR. c Drawing of the FRMFamide LIR in female Osedax nervous system. Color codes: blue, ventral nerves; green, oviduct nerves; grey, body outline; orange, palp nerves; pink, dorsal nerves; purple, dorso-lateral nerves; white, ciliary bands. Abbreviations: adn – antero-dorsal nerve, aon – anterior oviduct nerve, br – brain, cb – ciliary band, cvc – commissure of the vc, cvn – crossing neurites of the vc, ddn – dorso-diagonal nerve, dn – dorsal nerve, dln1-5 – dorso-lateral nerves 1-5, dlpn1,2 – dorsal left palp nerve 1, 2, dpnn – dorsal posterior nerve net, drpn1, 2 – dorsal right palp nerve 1, 2, mn – median nerve, oln – ovisac longitudinal nerves, pac – perikarya of the cvc, pcb – palp ciliary band, ron – ring ovisac nerve, rtn – ring nerve at the base of the trunk, svn – straight ventral neurites of the vc, vc – ventral cord, vcp – ventral cord projection, vcpp – posterior process of the vc, vln – ventro-lateral nerve, vlpn1, 2 – ventral left palp nerve 1, 2, vrpn1, 2 - ventral right palp nerve 1, 2