Euthelepus McIntosh, 1885

Hutchings, Pat, Nogueira, João Miguel Matos & Carrerette, Orlemir, 2015, Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 240-274 : 251

Genus Euthelepus McIntosh, 1885

Euthelepus . — Hutchings & Glasby 1986b: 105.

Type-species. Euthelepus setubalensis McIntosh, 1885 , by original designation.

Diagnosis. Transverse prostomium attached to dorsal surface of upper lip; basal part usually with eyespots; distal part low, restricted to base of upper lip. Buccal tentacles all uniformly cylindrical. Peristomium forming lips, continuing dorsally as narrow annulation, with nuchal organs on anterior margin; short, hood-like upper lip, about as long as wide or wider than long; lower lip also short, button-like, restricted to oral area. Short anterior segments, usually visible all around body, segment 1 with ventral lobe marginal to mouth, segments 2–3 or 2–4 with lateral or ventro-lateral lobes. Three pairs of branchiae, beginning from segment 2, each pair with relatively few, thick and elongate branchial filaments progressively tapering to tips, mid-dorsal gap between filaments of each side within pairs absent or very narrow, at least on segment 2. Anterior body highly glandular ventrally, swollen, smooth to corrugated between neuropodia. Notopodia beginning from segment 3, extending for variable number of segments; distally bilobed notopodia, post-chaetal lobe sometimes longer, chaetae emerging between lobes. Winged notochaetae in anterior row, posterior row with winged or serrated notochaetae, sometimes changing types from anterior to posterior segments with notopodia. Neuropodia beginning from segments 4 or 5, as fleshy ridges anteriorly, as raised pinnules after termination of notopodia. Neurochaetae throughout as short-handled avicular uncini, with dorsal button at anterior third of base, short, conspicuous prow, and strongly curved, convex base; uncini in single, straight rows. Nephridial and genital papillae frequently absent. Pygidium unknown ( Hutchings & Glasby 1986b).

Remarks. Hutchings & Glasby (1986b) revised this genus and considered that only three species belong to this group. The remaining species previously allocated in Euthelepus were transferred to Streblosoma (2 species) and Thelepus (4 species) ( Hutchings & Glasby 1986b). Two additional species were later described ( Hutchings 1997a; Londoño-Mesa 2009) and a sixth one is described herein.

The most important characters to distinguish the species of Euthelepus are the morphology of the lobes of anterior segments and branchiae, the number of pairs of notopodia, the segment on which neuropodia begin, and the morphology of notochaetae and uncini.