Hermadion Kinberg 1856

Genus Hermadion Kinberg, 1856, emended Type species. Hermadion magalhaensi Kinberg, 1856 Diagnosis. Body dorsoventrally flattened, short, with up to 50 segments; in large specimens mid-dorsum not completely covered by elytra and short tail uncovered. Fifteen pairs of elytra on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 26, 29, and 32. Prostomium bilobed, without cephalic peaks, with three antennae; lateral antennae inserted ventrally to median antenna; two pairs of eyes and a pair of palps present. Parapodia biramous, both rami with elongate acicular lobe; notopodia shorter and on anterodorsal side of neuropodia; neuropodia without supra-acicular process; tips of noto- and neuroacicula penetrating epidermis. Notochaetae stouter than neurochaetae, with numerous rows of spines and blunt tip; neurochaetae more numerous, with numerous rows of spines distally and unidentate tip. Remarks. The genera Harmothoe and Hermadion were both established by Kinberg (1856) with Harmothoe showing lateral antennae inserted ventrally, a rather short body, and 15 pairs of elytra covering the dorsum completely, while in Hermadion lateral antennae are also inserted ventrally, but the body is more elongate, 15 pairs of elytra leave the middorsum and the posterior segments uncovered, and neurochaetae have rows of spines reaching to the tip. Unfortunately, the body length and the degree of coverage of the dorsum by the elytra are difficult to evaluate in younger specimens (or insufficient for identification of anterior fragments). Moreover, in neurochaetae the amount of surface covered by rows of spines is an inadequate character, since in both Hermadion and Harmothoe this varies within the same bundle: in uppermost neurochaetae rows of spines can reach almost to the tip, while in middle and lower neurochaetae there is always a distinct bare area below the tip. Some authors, like Bergstr��m (1916), considered the differences insufficient and synonymized Hermadion with Harmothoe, while Augener (1932) regarded Hermadion as a valid genus. Our examination of the type material of Hermadion showed, that there are indeed additonal significant differences between these two genera: in Hermadion cephalic peaks are absent and the neuropodia have no supra-acicular process, but both structures are present in Harmothoe. For a detailed description of the characters of Harmothoe, see the revisions by Barnich et al. (2006) and Barnich and Fiege (2009) and Tables 1 and 2 below. The following discussion of species referred to other genera either by earlier authors or in the present study is summarized in Table 3. Malmgreniella, Polynoe, Subadyte: cf. Barnich and Fiege 2003; Hermadion: this study; Hermadionella: cf. Uschakov 1982). * in Barnich and Fiege (2003) neuroacicula of Polynoe described as not penetrating, but re-evaluation showed that both, noto- and neuroacicula are penetrating.
Published as part of Bock, Gordon, Fiege, Dieter & Barnich, Ruth, 2010, Revision of Hermadion Kinberg, 1856, with a redescription of Hermadion magalhaensi Kinberg, 1856, Adyte hyalina (G. O. Sars, 1873) n. comb. and Neopolynoe acanellae (Verrill, 1881) n. comb. (Polychaeta: Polynoidae), pp. 45-61 in Zootaxa 2554 on pages 46-47, DOI: 10.5281/zenodo.196874
{"references":["Kinberg, J. G. H. (1856) Nya slagten och arter af Annelider. Ofversigt af Kongliga Vetenskaps-Akademiens Forhandlingar, 12 (9 - 10), 381 - 388 [read 1855; printed 1856].","Bergstrom, E. (1916) Die Polynoiden der schwedischen Sudpolarexpedition 1901 - 1903. Zoologiska Bidrag fran Uppsala, 4, 269 - 304.","Augener, H. (1932) Polychaeten. Zoologische Ergebnisse der Reisen von Dr. Kohl-Larsen nach den Subantarktischen Inseln bei Neuseeland und nach Sudgeorien. 8. Senckenbergiana, 14 (3), 95 - 117.","Barnich, R., Fiege, D., Micaletto, G. & Gambi, M. C. (2006) Redescription of Harmothoe spinosa Kinberg, 1856 (Polychaeta, Polynoidae) and related species from Subantarctic and Antarctic waters, with the erection of a new genus. Journal of Natural History, 40 (1 - 2), 33 - 75.","Barnich, R. & Fiege, D. (2009) Revision of the genus Harmothoe Kinberg, 1856 (Polychaeta: Polynoidae) in the Northeast Atlantic. Zootaxa, 2104, 1 - 76.","Barnich, R. & Fiege, D. (2003) The Aphroditoidea (Annelida: Polychaeta) of the Mediterranean Sea. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 559, 1 - 167.","Uschakov, P. V. (1982) Polychaetes of the suborder Aphroditiformia of the Arctic Ocean and the northwestern part of the Pacific. Families Aphroditidae and Polynoidae. Fauna of the USSR. Polychaetes, 2 (1), 1 - 271 [in Russian]."]}