Loimia juani, 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 : 558-561

Loimia juani n. sp.

( Figs 3 D–F, 49–50)

Type material. Holotype: AM W.44961, MI QLD 2429, Casuarina Beach , 14°40'46"S, 145°26'49"E. Paratypes: AM W.47825, MI QLD 2336; AM W.44518, MI QLD 2381; AM W.44261, MI QLD 2335; AM W.44263, MI QLD 2336.

Comparative material examined. Holotype of Loimia batilla Hutchings & Glasby, 1988 , AM W.5162. Paratypes of Loimia batilla , AM W.7097, AM W.7098; AM W.7106, AM W.7107. Non-types of Loimia ingens ( Grube, 1878) , NTM W.6764, NTM W.6775, NTM W.17330. Holotype of Loimia ochracea ( Grube, 1878) , ZMB 906, MPW 583. Holotype of Loimia triloba Hutchings & Glasby, 1988 , BMNH ZB 1986.97.

Description. In life, body anteriorly reddish with paler, yellowish mid-ventral shields, buccal tentacles frequently with iridescent red and yellow inclusions ( Fig. 3 D–F). Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots, distal part shelf-like ( Fig. 49 B, E, G, K). Peristomium forming lips, hoodlike upper lip, short, almost circular, partially covered by lobes of segment 1; short and swollen lower lip, buttonlike ( Fig. 49 A, C–F, I–K). Segment 1 dorsally narrow, with pair of large lobes directed anteriorly and almost reaching tip of upper lip; lobes almost circular, dorsal margins inserted at level of branchiae; lobes higher laterally to mouth, mid-ventrally indented to partially expose lower lip. Segment 2 reduced, dorsally conspicuous, covered by lobes of segment 3 laterally and fused to it ventrally. Segment 3 with pair of almost circular lobes, almost same length as lobes of segment 1 laterally; lobes with narrow base, ventral edges fused to upper corners of first midventral shield, far from level of ventral edge of neuropodia, dorsal margins inserted at level of midlength of neuropodia; lobes of segment 4 shorter than lobes of segment 3, with distinctly narrow bases, ventral margins inserted at mid-length of neuropodial tori, dorsal margins at level of notopodia ( Fig. 49 A–G, I–K). Anterior segments laterally swollen. Paired dorso-lateral arborescent branchiae present on segments 2–4, dorsal to line of notopodia, with short branchial filaments branching dichotomously from secondary stems originating in a spiral from short basal stems; first pair slightly longer, about half body width at segment 2; pairs inserted progressively more laterally ( Fig. 49 A–G, I–K). Trapezoidal mid-ventral shields present on segments 2–13, those of segments 2– 4 almost completely fused into single crenulated structure, following shields slightly crenulated; blood red region on segments 12 to 15–16 ( Fig. 3 E–F); first 2 shields, on segments 2–4 and 5, much wider than those of following segments, then about same width, indented posteriorly by tori ( Fig. 49 A, C–D. F, I–J). Dorsum smooth throughout, rows of rounded tubercles absent. Notopodia beginning on segment 4, extending until segment 20; notopodia short, cylindrical to oblong, notopodia of segments 4–7 inserted progressively more laterally, then longitudinally aligned ( Fig. 49 A–K). Narrowly-winged notochaetae in both rows throughout, those from posterior row with wings at distal half ( Fig. 50 A–C). Neuropodia present from segment 5, as low, almost sessile ridges until termination of notopodia, as elongate and thin, rectangular pinnules, from segment 21, inserted progressively more ventrally, lateral to mid-ventral groove on posterior segments ( Fig. 49 A, C–F, H–J). Pectinate short-handled avicular uncini, arranged in partially intercalated to completely separate double rows, in back to back arrangement, from segment 11 until termination of notopodia, on segment 20; uncini with short base, poorly defined dorsal button at midlength of base, prow distally curved downwards, and crest with single vertical series of 5–6 progressively shorter secondary teeth throughout; main fang larger but not clearly defined, line of teeth aligned with tip of prow ( Fig. 50 D–H). Nephridial papillae on segment 3, between dorsal margins of lobes and bases of branchiae, genital papillae on segments 6–8, posterior to notopodia; all papillae minute. Pygidium crenulate to slightly papillate ( Fig. 3 D). Tube mucous, with small stones and shell fragments embedded.

Remarks. Loimia juani n. sp. is characterized by the presence of lateral lobes on segment 4. Such lobes are also present in the Australian species L. triloba Hutchings & Glasby, 1988 and L. pseudotriloba n. sp., described below, but the morphology of these lobes varies, as in L. pseudotriloba n. sp., they extend to the level of mid-length of neuropodia, whereas in both the other species they extend to the level of notopodia. Loimia juani n. sp. can be distinguished from L. triloba by the absence of prostomial eyespots and the shape of the ventral pads of segments 2–4, almost completely fused to form a single crenulated structure, in the former species, which differs to that found in L. triloba , where all the pads are clearly separated. The habitats occupied by these two species also differ as L. juani n. sp. is associated with the reef, whereas L. triloba was dredged from inter-reefal sediments. For more detailed comparisons, see Carrerette & Nogueira (2015).

Etymology. We have named this after Juan Gonzalez-Vallarino, our wonderful chef during LIRS workshop, who provided us with wonderful food throughout the workshop, and his two young children provided an endless source of amusement.

Type locality. Casuarina Beach , 14°40'46"S, 145°26'49"E, Lizard Island, GBR, Australia.

Distribution. Only known from Lizard Island.

Figures

FIGURE 3. Live specimens. A – C. Loimia pseudotriloba n. sp. AM W. 47810, MI QLD 2336; D – F. Loimia juani n. sp.; D. AM W. 44261, MI QLD 2335; E. AM W. 44518, MI QLD 2381; F. AM W. 44263, MI QLD 2336; G – I. Lanice viridis n. sp. AM W. 44611, MI QLD 2400. Photos: A – I—Alexander Semenov.

FIGURE 49. Loimia juani n. sp. AM W. 44961: A. Incomplete worm, ventral view; B – C. Thorax, dorsal and right ventrolateral views, respectively; D – G. Anterior end, right ventro-lateral, left lateral, ventral and dorsal views, respectively; H. Close up of the transition between anterior and posterior body, right ventro-lateral view; I – K. Close ups of the anterior end, ventral, right ventro-lateral and dorsal views, respectively. Numbers refer to segments. Abbreviations: ul = upper lip. Scale bars: A – C = 1.5 mm, D – H = 1 mm, I – J = 0.7 mm, K = 0.6 mm.

FIGURE 50. Loimia juani n. sp. AM W. 44961: A – C. Notochaetae of segments 6 and 17 (2), respectively; D – H. Uncini, segments 23 (2), posterior body, 5, 11, respectively. Scale bars: A – B = 50 µm, C = 30 µm, D, F = 40 µm, E, G – H = 20 µm.