Pista kristiani, 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 : 522-525

Pista kristiani n. sp.

( Figs 2 A–B, 26–27)

Type material. Holotype: AM W.45451, MI QLD 2445, north of North Point, 14°38'35"S, 145°27'9"E. Paratypes: AM W.40291, off Station Beach, Lizard Island, 14°40'S, 145°28'E, 6 Jan 1975, posteriorly incomplete, 5 mm long, 1.5 mm wide; AM W.47740, CReefs, LI–10–62, MacGillivray Reef, 14°39'24"S, 145°29'34"E, complete specimen, with 86 segments, more or less in good state of preservation, with anterior end damaged, body almost severed in two pieces between segments 26 and 27, 17 mm long, 1.4 mm wide.

Comparative material examined. Holotype of Pista curtiuncinata Hartmann-Schröder, 1981 , HZM P16500. Holotype of Pista kimberliensis Hutchings & Glasby, 1990 , AM W.203525. Holotype of Pista pectinata Hutchings, 1977 , AM W.6795. Holotype of Pista pegma Hutchings & Smith, 1997 , AM W.22574. Holotype of Pista trina Hutchings, 1977 , AM W.6798. Holotype of Pista trunca Hutchings, 1977 , AM W.6973. Holotype of Pista typha Grube, 1878 , MPW 518. Holotype of Pista violacea Hartmann-Schröder, 1984 , NTM W.1644.

Description. In life, pink to red body and branchiae, with white lobes and colourless buccal tentacles ( Fig. 2 A–B). Transverse prostomium attached to dorsal surface of upper lip; basal part with few eyespots dorso-laterally, covered by lobes of segment 1, a single row of eyespots at base of of prostomium, terminating far away from dorsal mid-line, leaving wide mid-dorsal gap; distal part shelf-like. Short buccal tentacles, reaching around mid-length of region with notopodia ( Figs 2 A–B; 26A–H, J–M). Peristomium forming lips, hood-like upper lip, short, about as wide as long, circular; short and swollen lower lip button-like ( Fig. 26 C, L). Segment 1 narrow, with pair of large, almost rectangular lobes directed anteriorly and reaching tip of upper lip; lobes originating ventro-laterally, at level of dorsal edges of neuropodia; dorsal and distal edges straight, lobes connected to each other by thinner indented membrane ventrally, partially exposing lower lip; anterior margins of anterior segments as protruding crests dorsally, segment 2 also with mid-ventral crest, with pair of rounded ventro-lateral lobes; segment 3 with pair of developed lateral lobes, larger than those segment 2, reaching mid-length of lobes of segment 1, lobes distally rounded, triangular to semi-circular, aligned with line of notopodia dorsally and ventral edges of neuropodia, ventrally; segments 4 and 5 with much lower, progressively shorter lateral lobes, those of segment 4 continuing dorsally as low collar (= sinus) ( Figs 2 A–B; 26A–H, J–M). Anterior segments not very inflated dorsally. Paired dorso-lateral arborescent branchiae present on segments 2–3, usually first pair distinctly larger and inserted more dorsally, but frequently missing one or both branchiae of a pair; each branchia with conspicuous, crenulate basal stem, and secondary stems originating all at same point and further branching dichotomously for few levels ( Figs 2 A–B; 26A–H, J–M). Smooth, slightly corrugated anteriorly mid-ventral shields present on segments 2–20, rectangular to trapezoidal, about same size until segment 11, then progressively longer and narrower to segment 17, last 3 pairs much shorter, almost inconspicuous ( Fig. 26 A, C, I, L–M). Notopodia beginning on segment 4, extending until segment 20; notopodia short, rectangular, first pair much shorter, notopodia of segments 4–8 inserted progressively more laterally, then longitudinally aligned ( Fig. 26 A–K, M). Broadly-winged notochaetae in both rows, those of anterior row with wings broader on one side, bulbous, and chaetae in posterior row with wings almost throughout, except for basal third ( Fig. 27 B–D). Neuropodia present from segment 5, as low, almost sessile ridges until termination of notopodia, as low rectangular pinnules thereafter ( Figs 26 A–M; 27A). Neurochaetae as long-handled avicular uncini on segments 5–20, until termination of notopodia, with well developed handles originating from heel only; uncini arranged in completely intercalated double rows on segments 11–20; avicular uncini throughout, with short, triangular and distally rounded heel, rounded prow, dorsal button at mid-length, conspicuous throughout, and crest with 4 rows of numerous, progressively shorter secondary teeth, on anterior segments and after notopodia terminate, 3 rows on segments 11–20, and 5 rows posteriorly ( Fig. 27 E–K). Nephridial papillae of segment 3 not visible, genital papillae on segments 6–7, posterior notopodia and dorsal to notopodia or longitudinally aligned to them, visibility depending on maturity of specimens ( Fig. 26 J). Pygidium crenulate, with larger and rounded ventral papillae ( Fig. 27 A). Tube unknown.

Remarks. Pista kristiani n. sp., which has two pairs of dichotomous branchiae and all thoracic uncini with well developed handles, most closely resembles P. sinusa Hutchings & Glasby, 1988 , P. t runca Hutchings & Glasby, 1988 and P. turawa Hutchings & Glasby, 1988 . However, the new species can easily be distinguished from P. sinusa and P. t r u nc a because in these two species the lobes of segment 3 form a dorsal sinus, which is also present in P. kristiani n. sp., but on segment 4, and not connected to the lobes of segment 3.

Pista turawa can be separated from Pista kristiani n. sp. as P. turawa completely lacks lobes on segment 2, which are present ventro-laterally in the new species. For this reason Pista kristiani n. sp. is described as a new species.

Etymology. This species is named after Dr Kristian Fauchald, who visited Lizard Island several times, and inspired all of us to study polychaetes and to continue to investigate their diversity and beauty.

Type locality. North of North Point, 14°38'35"S, 145°27'9"E, Lizard Island, GBR, Australia.

Distribution. Known only from the Lizard Island region.

Figures

FIGURE 2. Live specimens. A – B. Pista kristiani n. sp. AM W. 45451, MI QLD 2445; C – D. Lanicides rubra n. sp. AM W. 44272, MI QLD 2344; E – G. Eupolymnia chlorobranchiata n. sp. AM W. 45455, MI QLD 2446; H – I. Pistella franciscana n. sp. H. Discarded specimen; I. AM W. 44593, MI QLD 2394; J – L. Loimia tuberculata n. sp; J – K. Spec. AM W. 44280, MI QLD 2359; L. Discarded specimen. Photos: A – K—Alexander Semenov, L—Gary Cranitch.

FIGURE 26. Pista kristiani n. sp. AM W. 45451: A – B. Entire worm, left ventro-lateral and right dorso-lateral views, respectively; C – H. Anterior end in ventral, right dorso-lateral, right and left lateral, dorsal and right ventro-lateral views respectively; I. Transition between anterior and posterior body; J – M. Close ups of the anterior end, dorsal, right lateral, ventral and left lateral views, respectively; arrows point to genital papillae. Scale bars: A – B = 1 mm, C – D = 0.6 mm, E – F, H = 0.7 mm, G, I = 0.5 mm, J – M = 0.3 mm.

FIGURE 27. Pista kristiani n. sp. AM W. 45451: A. Posterior end (damaged), left lateral view; B – D. Notochaetae, segments 6, 18 (2), respectively; E – F. Anterior uncini, segment 6; G. Mid-body uncini, segment 18; H – I. Posterior uncini, segment 70; J – K. Posterior uncini, segment 22. Scale bars: A = 0.2 mm, B – D = 30 µm, E, H – I, K = 10 µm, F – G, J = 15 µm.