Terebellides Sars 1835

Genus Terebellides Sars, 1835, emended

Terebellides. — Hutchings & Peart 2000: 238 –239; Muir 2011: 144.

Type-species. Terebellides stroemii Sars, 1835, by monotypy.

Diagnosis. Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part extending along dorsal margin of upper lip until near anterior margin. Buccal tentacles usually of two types, uniformly cylindrical and expanded at tips. Peristomium forming lips, continuing dorsally as narrow annulation; relatively large upper lip, circular and slightly convoluted; lower lip expanded, forming scoop-like process. Short anterior segments, segment 1 visible ventrally, posterior to lower lip, sometimes also conspicuous dorsally; following anterior segments with lobes as low ventral collars. Single 1–5 lobed lamellate branchia inserted by thick branchial stem between segments 2–3 or 2–4. Anterior body poorly glandular ventrally, smooth. Notopodia beginning from segments 3 or 4, terminating on segment 20; if beginning from segment 3, first pair shorter than following ones; short, conical notopodia, not bilobed. Narrowly-winged notochaetae in both rows, wings inconspicuous under light microscopy, visible as short and fine hairs under SEM. Neuropodia beginning from segments 7 or 8, uncini emerging directly from body wall. Neurochaetae of first 1–2 segments as thin, distally tapered acicular spines, following neuropodia with acicular uncini until end of notopodia; abdominal neuropodia as foliaceous pinnules, bearing avicular uncini. Nephridial papillae only on segment 3, genital papillae, if present, on segments 6–7, at bases of notopodia, posterior and dorsal. Pygidium smooth to slightly crenulate.

Remarks. Terebellides is a well known genus, characterized by the highly unusual branchia. The type species, T. stroemii Sars, 1835, has been reported worldwide and is clearly a case of a complex of sibling species. In a recent redescription of T. stroemii, Parapar & Hutchings (2014) designated a neotype, redefined this species and suggested it is restricted to Northern Atlantic waters. Work in progress utilising both molecular and morphological tools is revealing many other species currently undescribed in this region of the North Atlantic (Parapar, Hutchings & others, in prep.), all closely resembling T. stroemii morphologically, but differing genetically.

Hutchings & Peart (2000) reviewed this genus in Australia and described four new species, but we suspect additional species occur. This is confirmed by the present study, in which we describe a new species from Lizard Island.