Hauchiella Levinsen, 1893

Nogueira, João Miguel Matos, Hutchings, Pat & Carrerette, Orlemir, 2015, Polycirridae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 437-483 : 440

Genus Hauchiella Levinsen, 1893

Hauchiella .— Hutchings & Glasby 1986: 323.

Type-species. Polycirrus tribullata McIntosh, 1869 , by original designation.

Diagnosis. Transverse prostomium attached to dorsal surface of upper lip; basal part usually as thick horseshoeshaped crest, frequently covering segment 1 laterally and terminating lateral to mouth; distal part as flaring lobe restricted to base of upper lip. Buccal tentacles of at least two types, short ones uniformly cylindrical, long ones spatulated; stouter and longer tentacles specialised at tips may also be present. Peristomium forming lips; upper lip relatively short, hood-like, circular to elliptical; swollen lower lip, button-like, restricted to oral area. Segments throughout biannulated or with more annulations, segment 1 reduced, usually visible dorsal and ventrally, laterally covered by expanded prostomium. Segment 2 distinctly short, narrower than following segments, usually with rectangular or pentagonal mid-ventral shield at beginning of mid-ventral groove, sometimes extending anteriorly through segment 1 until near posterior margin of lower lip. Body wall with transverse rows of papillae throughout or only anteriorly, papillae distinctly larger and more abundant on ventro-lateral pads of anterior segments, these usually present from segment 2. Parapodia absent throughout. Nephridia usually visible by transparency through body wall, genital papillae or pores only usually present. Pygidium smooth to crenulated, or with rounded ventral papilla.

Remarks. Hauchiella is a very unusual genus of polychaetes. The genus lacks both noto- and neuropodia, and, consequently, completely lacks chaetae; therefore members of Hauchiella challenge the definition of polychaetes as a whole. However, the affiliation of the species of Hauchiella to Terebelliformia and, consequently, to polychaetes, is undeniable, requiring the name Polychaeta to include forms with no chaetae at all. On the other hand, the absence of both noto- and neuropodia, characters used to distinguish between species of the other genera of polycirrids, results in very few characters available to distinguish between species of Hauchiella . Two species of Hauchiella were known prior to this study, we describe a third species herein.