Reteterebella lirrf, Nogueira, João Miguel Matos, Hutchings, Pat & Carrerette, Orlemir, 2015

Nogueira, João Miguel Matos, Hutchings, Pat & Carrerette, Orlemir, 2015, Terebellidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 484-576 : 506-508

Reteterebella lirrf n. sp.

( Figs 1 E–H, 14–15)

Type material. Holotype: AM W.47708, Coconut Beach, Lizard Island, 14°40'S, 145°28'E, 20 Nov 1985, posteriorly incomplete, 60 mm long, 20 mm maximum width. Paratypes: AM W.44545, MI QLD 2416, posteriorly incomplete, 65 mm long, 15 mm maximum width; AM W.47709 (2), CReefs, LI–10–052, MI QLD 2206, Turtle Bay, 14°39'14"S, 145°26'59"E, 1 complete specimen in excellent shape, 500 mm long, 12 mm maximum width, other posteriorly incomplete; AM W. 200132, Coconut Beach, Lizard Island, 14°40'S, 145°28'E, 20 Nov 1985, well preserved, complete but in 3 pieces, anterior section 70 mm long, 15 mm maximum width, mid section 30 mm long, 6 mm wide, posterior section 60 mm long, 5 mm wide; AM W.29559, off Mermaid Cove, North Point, 14°39'S, 145°27', Mar 1995, complete but in 2 pieces, anterior 70 mm long, 12 mm maximum width and posterior piece 35 mm long, 8 mm maximum width.

Other material examined. AM W.47710 (incomplete), CReefs, LI–10–052, MI QLD 2206, Turtle Bay, 14°39'14"S, 145°26'59"E.

Comparative material examined. Holotype of Reterebella queenslandia Hartman, 1963 , AM W.3755.

Description. In life pinkish white body with dark red, brownish branchiae ( Fig. 1 E–H). Transverse prostomium attached to dorsal surface of upper lip; basal part with eyespots in a continuous row, mid-dorsal gap absent; distal part shelf-like. Long, bright white buccal tentacles lacking any pigmentation, several times longer than body length, highly extensile ( Figs 1 E–H; 14A–H). Peristomium forming lips, hood-like upper lip short, nearly circular, as long as wide; short and swollen lower lip button-like. Segment 1 narrow, ventrally fused to lower lip, segment 2 with thickened anterior margin, protruding as a ventral crest; low, flaring, mostly ventro-lateral lobes present on segments 2–5, wider on segment 2, from sides of mouth to lateral body, progressively narrower until segment 5 ( Fig. 14 B, F–H). Anterior segments inflated dorsally. Paired dorso-lateral arborescent branchiae present on segments 2–4, each with short, dichotomously branching basal stem, ending by relatively short filaments; progressively shorter pairs, all longitudinally aligned ( Fig. 14 A–H). Ventral shields from segment 4 to last with notopodia, rectangular, deeply corrugated, progressively narrower until last, on segment 20, last 2–3 pairs much narrower, only mid-ventral ( Fig. 14 B, F–H). Notopodia beginning on segment 5, extending until segment 20; notopodia short, rectangular, all longitudinally aligned, first pair slightly shorter ( Fig. 14 A–H). Narrowly-winged notochaetae in both rows, those from posterior row with wings at distal half only ( Fig. 14 I–L). Neuropodia present from segment 5, as low, almost sessile ridges until termination of notopodia, as low rectangular pinnules thereafter; wide tori on anterior segments, ventral edges of tori of last 4 segments with notopodia almost reaching ventral midline ( Fig. 14 A–H). Neurochaetae throughout as short-handled avicular uncini, arranged in double rows from segment 10 to last with notopodia, segment 20; rows partially intercalated, dorsal buttons aligned; angular, sharpangled uncini throughout, with short triangular heel, distally pointed prow, dorsal button at mid-length, and crest with 2 teeth above main fang and perhaps a second row as single, minute tooth between teeth of first row ( Fig. 15 A–D). Nephridial and genital papillae on segments 3–8, those on segments 3 and 4 elongate, inserted ventrally to branchiae, those on segments 5–8 rounded, situated between notopodia and neuropodia, more ventral than those of segments 3 and 4. Pygidium smooth to slightly crenulate. Lives in flimsy tube which lines the burrow deep within the coral, made of very fine coralline sediment.

Remarks. Morphologically, R. queenslandia and R. lirrf n. sp. are very similar species, sharing similar body measurements, number of pairs of notopodia, beginning of noto- and neuropodia, and of double rows of uncini, and morphology of lobes on segments 2–5, notochaetae and uncini. These species differ, however, in addition to the different life habitats, because specimens from Lizard Island R. lirrf n. sp. have deeply corrugated mid-ventral shields extending through all segments with notopodia, although the last pairs are much shorter, while R. queenslandia material only has mid-ventral shields on anterior segments with notopodia, and these are smooth. In addition, there is a slight difference in the morphology of the uncini, as in R. lirrf n. sp. the prow is more abruptly inclined (compare Figs 13 J– O and 15A–D). Both these species can easily be distinguished from the other species of the genus, R. aloba Hutchings & Glasby, 1988 , which completely lacks lobes and is a much smaller species.

Although not a borer, this new species lives deep inside crevices within the reef substrate, and spreads its highly extensile buccal tentacles over the substrate, from narrow openings on the reef structure. The Australian Museum database has no other records from the GBR other than those from Lizard Island, which all represent Reterebella lirrf n. sp. We also know that it occurs at Milln Reef, off Cairns (OC pers observ.). The lack of museum records is almost certainly due to the difficulty in extracting this species from deep down in the reef structure. However, this has not prevented numerous photographs of this genus occurring in coral reef books, with the white buccal tentacles extending over the reef floor, and we suggest that any specimen photographed in waters below 3– 5 m belong to this new species, especially where surrounded by living coral.

Etymology. This species is called “ lirrf ”, after the acronym of the Lizard Island Reef Research Foundation, which generously supported this polychaete workshop.

Type locality. Coconut Beach, 14°40'S, 145°28'E, Lizard Island, GBR, Australia.

Distribution. Currently only known from Lizard Island, but likely occurs elsewhere on the GBR.

Figures

FIGURE 1. Live specimens. A – B. Nicolea murrayae n. sp. AM W. 44603, MI QLD 2397; C. Nicolea vaili n. sp. AM W. 44487, MI QLD 2335; D. Pista anneae n. sp. AM W. 44513, MI QLD 2370; E – H. Reteterebella lirrf n. sp. AM W. 44545, MI QLD 2416; I – J. Pista chloroplokamia n. sp., AM W. 44613, MI QLD 2400. Photos: A – J—Alexander Semenov.

FIGURE 13. Reteterebella queenslandia AM W. 47705, MI QLD 2261: A – B. Entire worm, right and left lateral views, respectively; C – D, G. Anterior end in progressively higher magnifications, right lateral views, respectively; E – F. Progressively closer views of the anterior end, left lateral view; H – I. Notochaetae, segments 8 and 18, respectively; J – M. Uncini, segments 8, 18 (2), 24, respectively; N – O. Posterior uncini. Numbers refer to segments. Abbreviations: ul = upper lip. Scale bars: A – B = 1 cm, C = 0.6 mm, D, F = 0.3 mm, E, G = 0.4 mm, H = 100 µm, I = 80 µm, J – M, O = 20 µm, N = 40 µm.

FIGURE 14. Reteterebella lirrf n. sp. AM W. 47708: A – B. Entire incomplete worm, left and right lateral views, respectively; C – H. Anterior end in progressively higher magnifications, left dorso-lateral and right ventro-lateral views, respectively; I – J. Notochaetae, segment 7; K – L. Notochaetae, segment 19. Numbers refer to segments. Abbreviations: ul = upper lip; * = distal part of prostomium. Scale bars: A – B = 1 cm, C, F = 5 mm, D, G = 4 mm, E, H = 3 mm, I – K = 100 µm, L = 50 µm.

FIGURE 15. Reteterebella lirrf n. sp. AM W. 44545: A – D. Uncini, segments 7, 19, 23 and posterior uncini, respectively. Scale bars: A – D = 20 µm.