Lanicola rectangulata, 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 : 545

Lanicola rectangulata n. sp.

( Figs 39–40 )

Type material. Holotype: NTM W. 023131, Day Reef, Outer Barrier, 14°28'35"S, 135°32'38"E, 12 m, 13 mm long, 2 mm wide, posteriorly incomplete. Paratype: AM W.44604, MI QLD 2399.

Comparative material examined. Non types of Lanicola lobata Hartmann-Schröder, 1986 , MV F.91199, NTM W.3667.

Description. Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots, distal part shelf-like ( Fig. 39 A–G, I–K). Peristomium forming lips, hood-like upper lip, short, wider than long; short and swollen lower lip, button-like ( Fig. 39 A, C, G, J–K). Segment 1 dorsally narrow, developed ventrally with high ventral lobe marginal to mouth; anterior margins of segments 2–6 as progressively lower protruding crests ventrally; segment 3 with pair of low rectangular lobes, with straight lateral and distal margins, ventral margins fused to mid-ventral shield of segment 2, with conspicuous scar at line of fusion extending until anterior margin of segment 3, dorsal margins inserted near line of notopodia; from segment 4, lobes absent ( Fig. 39 A–G, I–K). Anterior segments slightly inflated dorsally. Paired dorso-lateral arborescent branchiae present on segments 2–3, dorsal to line of notopodia, with branchial filaments branching dichotomously at few levels from short basal stems; first pair longer, more than half of body width of segment 2, dorsally aligned to second pair ( Fig. 39 A–F, I, K). Mid-ventral shields present on segments 2–19, rectangular, compact on anterior segments, progressively longer on segments 6–11, then of uniform length until segment 18, last shield shorter; all shields slightly crenulate ( Fig. 39 A, C, G, J–K). Notopodia beginning on segment 4, extending until segment 20; notopodia short, rectangular, first pair shorter, notopodia of segments 4–7 inserted progressively more laterally, then longitudinally aligned ( Fig. 39 A–I). Narrowly-winged notochaetae in both rows throughout, those from posterior row with wings at distal half ( Fig. 40 A–C). Neuropodia present from segment 5, as low, almost sessile ridges until termination of notopodia, as low, rectangular pinnules thereafter ( Fig. 39 A–D, G–K). Short-handled uncini throughout, with dorsal button at midlength, distally rounded prow and 3 transverse rows of secondary teeth, on anterior segments, and 2 rows from segment 11 ( Fig. 40 D–F). Nephridial papillae on segments 3 and 4, posterior to notopodia, genital papillae on segments 6 and 7, dorsal to notopodia ( Fig. 39 B, D–F, I). Pygidium and tube unknown.

Remarks. Lanicola rectangulata n. sp. is the second species of this genus found in Australian waters; the other species is L. lobata , the type species of the genus, which was described from SA. These species differ because L. lobata is a distinctly larger species, with triangular, distally rounded lobes on segment 3, while in L. rectangulata n. sp. these lobes are rectangular and proportionally longer than in L. lobata .

Etymology. We name this species after the rectangular shape of the lobes of segment 3.

Type locality. Day Reef, 14°28'35"S, 135°32'38"E, Outer Barrier, GBR, Australia.

Distribution. Known only from the type locality.

Figures

FIGURE 39. Lanicola rectangulata n. sp. NTM W. 023131: A – B. Incomplete worm, left ventro-lateral and right dorso-lateral views, respectively; C – G. Anterior end, left ventro-lateral, right dorso-lateral, dorsal (2) and ventral views, respectively; H. Transition between anterior and posterior body, right dorso-lateral view; I – K. Close ups of the anterior end, right dorso-lateral, ventral and left ventro-lateral views, respectively. Numbers refer to segments, unspecified arrows point to nephridial and genital papillae. Abbreviations: ll = lower lip, P = prostomium, ul = upper lip. Scale bars: A – B = 1 mm, C – D, G = 0.5 mm, E = 0.4 mm, F, H – K = 0.3 mm.

FIGURE 40. Lanicola rectangulata n. sp. NTM W. 023131: A, C. Notochaetae under higher magnifications, segment 9, general and chaetae from posterior row, respectively; B. Notochaetae, segment 17; D – F. Uncini from the segments 5, 11, 23, respectively. Scale bars: A – B = 50 µm, C = 30 µm, D – F = 20 µm.