Amaeana brasiliensis, Nogueira, João Miguel De Matos, Carrerette, Orlemir & Hutchings, Pat, 2015

Nogueira, João Miguel De Matos, Carrerette, Orlemir & Hutchings, Pat, 2015, Review of Amaeana Hartman, 1959 (Annelida, Terebelliformia, Polycirridae), with descriptions of seven new species, Zootaxa 3994 (1), pp. 1-52 : 47-50

Amaeana brasiliensis sp. nov.

Figures 17 E–F, 24F–I, 28, 29

Amaeana sp. Nonato 1981: 208 –210. Alves 2008: 113 –118, Figs 42–43. Amaeana sp. nov. Carrerette 2015: 24–27, Figs 5–7 .

Material examined. Project HABITATS/PETROBRAS: State of Rio de Janeiro—Campos Basin: Mouth of River Paraíba do Sul: Holotype MZUSP 2349 (coll. 22°11'30.342"S, 40°55'30.995"W, 44 m, 17.Jul.2009): complete, in good state of preservation. Paratypes: MZUSP 2726 (coll. 22°11'27.630"S, 40°55'30.234"W, 44 m, 12.Mar.2009): complete, in good state of preservation, in two fragments, anterior piece ~ 13 mm long, ~ 2.1 mm maximum width, posterior piece 8 mm long, ~ 1 mm wide. MZUSP 2727 (coll. 22°11'26.173"S, 40°55' 30.544"W, 44 m, 17.Jul.2009): complete, in good state of preservation, in two fragments, anterior piece ~ 7 mm long, ~ 1.5 mm maximum width, posterior piece ~ 6 mm long, ~ 1 mm wide. MZUSP 2728 (coll. 22°11'27.630"S, 40°55'30.234"W, 44 m, 12.Mar.2009): complete, in good state of preservation, in two fragments, anterior piece ~ 9 mm long, ~ 2.1 mm maximum width, posterior piece 10 mm long, ~ 1 mm wide. MZUSP 2729 (coll. 22°6'16.830"S, 40°43'45.468"W, 47 m, 12.Mar.2009): complete, in good state of preservation, in two fragments, anterior piece ~ 12 mm long, ~ 2.1 mm maximum width, posterior piece 6 mm long, ~ 2 mm wide. MZUSP 2730 (coll. 22°11'26.173"S, 40°55'30.544"W, 44 m, 17.Jul.2009): incomplete, in good state of preservation, in two fragments, anterior piece ~ 9 mm long, ~ 2.1 mm maximum width, posterior piece 6 mm long, ~ 1 mm wide. MZUSP 2731 (coll. 22°11'26.173"S, 40°55'30.544"W, 44 m, 17.Jul.2009): complete, in good state of preservation, in two fragments, anterior piece ~ 8 mm long, ~ 2 mm maximum width, posterior piece 4 mm long, ~ 2 mm wide. MZUSP 2732 (coll. 22°8'4.874"S, 40°27'33.592"W, 65 m, 23.Feb.2009): incomplete, in good state of preservation, ~ 14 mm long, ~ 4 mm maximum width. MZUSP 2733 (coll. 22°11' 27.491"S, 40°55'30.498"W, 44 m, 19.Jul.2009): incomplete, in good state of preservation, ~ 8 mm long, ~ 2 mm maximum width. MZUSP 2734 (coll. 22°12'48.612"S, 40°51'18.120"W, 55 m, 26.Jul.2009): incomplete, in good state of preservation, ~ 10 mm long, ~ 2 mm maximum width. MZUSP 2735 (coll. 21°33'48.690"S, 40°43'1.692"W, 21 m, 10.Mar.2009): incomplete, in good state of preservation, mounted on SEM stub.

Additional material examined: Project HABITATS/PETROBRAS: State of Rio de Janeiro—Campos Basin: Mouth of River Paraíba do Sul: MZUSP 2736 (coll. 22°11'27.733"S, 40°55'30.228"W, 44 m, 12.Mar.2009): 1 incomplete specimen, in good state of preservation. MZUSP 2737 (coll. 22°8'4.874"S, 40°27'33.592"W, 65 m, 23.Feb.2009): 1 incomplete specimen, in good state of preservation. MZUSP 2738 (coll. 22°11'27.630"S, 40°55'30.234"W, 44 m, 12.Mar.2009): 5 incomplete specimens, in good state of preservation. MZUSP 2739 (coll. 22°11'27.738"S, 40°55'30.216"W, 45 m, 12.Mar.2009): 3 incomplete specimens, in good state of preservation. MZUSP 2740 (coll. 22°6'17.598"S, 40°43'45.318"W, 47 m, 12.Mar.2009): 1 incomplete specimen, in good state of preservation. MZUSP 2741 (coll. 22°3'33.980"S, 40°7'5.610"W, 90 m, 07.Jul.2009): 1 incomplete specimen, in good state of preservation. Project “ BIOTA /FAPESP/Benthic Marine Biodiversity on the State of São Paulo”— Ubatuba: MZUSP 2742 (coll. 23°32'S, 44°43'W, 45 m, 17.Mar.2001): 1 incomplete specimen, in poor state of preservation.

Type locality. Campos Basin, Mouth of River Paraíba do Sul, State of Rio de Janeiro. 22°11'30.342"S, 40°55'30.995"W, 44 m.

Description. Holotype complete specimen, 13 mm long, 1.5 mm wide at segment 8, maximum width of body, counting on ~40 segments.

Prostomium at base of upper lip, both basal and distal parts developed, basal part as thickened crest, distal part with large, flaring lobes, and short and rounded mid-dorsal process not as clearly defined as in other species, raised; prostomium covering segment 1 laterally and terminating laterally to lower lip, near mouth ( Figs 28 A–F; 29A–C, E–F). Three types of buccal tentacles, short ones thin, uniformly cylindrical; intermediate tentacles distally broader, spatulate; long buccal tentacles progressively widening towards clearly marked subdistal cylindrical inflation, with short and pointed tips ( Figs 28 A–B, D–E, G; 29A).

Peristomium restricted to lips, upper lip elliptical, higher than broad, slightly convoluted; lower lip short, rounded ( Figs 28 A–D, F; 29B–C, E–F). Body progressively broader until segments 7–8, then tapering on segments 10–11 and again, more abruptly, on segments 15–19, to an uniformly cylindrical posterior body, beginning from segment 21, tapering posteriorly towards pygidium ( Figs 28 A–F, H; 29A–B, D, F); most specimens anterior fragments, broken at segment 19, at termination of tapering zone; achaetous gap between termination of notopodia and beginning of neuropodia, corresponding to segments 14–20, with poorly marked segmentation and fragile, thin body wall dorsally, as long as region with notopodia, or slightly shorter ( Figs 28 A–C, F; 29A, D).

Segments biannulated, segment 1 short, visible dorsally and ventrally, laterally covered by expanded prostomium; segment 2 narrower and shorter than following segments, with relatively short, pentagonal midventral shield at beginning of mid-ventral groove, extending anteriorly through segment 1 to near ventral edge of lower lip ( Figs 28 A–F; 29A–C, E–F). Ventrum highly glandular, covered with small papillae, arranged in paired ventro-lateral pads on segments 2–13, papillae progressively less abundant on segments 12–13, then smooth body wall, with paired longitudinal crests bordering mid-ventral groove through posterior body ( Figs 28 A–F; 29A–F).

Notopodia extending through 11 segments, until segment 13; elongate, cylindrical notopodia, with equal sized lobes and elongate and distally blunt tips ( Figs 28 A–F; 29B, D, F–G). Acicular, narrowly-winged notochaetae in both rows, wings barely visible under higher magnifications of light microscopy ( Fig. 24 F–G), as numerous short and fine hairs under SEM ( Figs 17 E–F; 29G).

Neuropodia present from segment 21, laterally to mid-ventral groove; neurochaetae up to 2–3 relatively stout, distally tapered spines, in different lengths, longer ones usually protruding from neuropodial lobes; tips of spines thinner, flattened, longer spines distally blunt, remaining spines with somewhat oblique tips ( Figs 24 H–I; 29H–J).

Nephridial and genital papillae anterior and slightly ventral to bases of all notopodia, enlarged on segments 6– 10. Pygidium with rounded ventral papilla ( Fig. 28 H).

Remarks. Members of A. brasiliensis sp. nov., were first described in an unpublished thesis ( Nonato 1981). The species was later redescribed in two other theses ( Alves 2008; Carrerette 2015), but a formal description was not provided until now. Amaeana brasiliensis sp. nov., is characterised by having notopodia extending to segment 13 (11 pairs of notopodia), achaetous gap of 7 segments between termination of notopodia and beginning of neuropodia, on segments 14–20, and 2–3 stout spines per neuropodium. Since A. antipoda is now a nomem nudum, the only other species of Amaeana with 11 pairs of notopodia is A. dampierensis sp. nov., but in this species the achaetous gap between the termination of the notopodia and the beginning of the neuropodia is longer, with the neuropodia beginning from segment 26–27 and bearing 4–5 spines each ( Table 1). In addition, the mid-ventral shield of segment 2 of members of A. dampierensis sp. nov. is distinctly larger than that of specimens of A. brasiliensis sp. nov.

Figures

FIGURE 5. Amaeana hsiehae sp. nov., ASIZW 0000935. A – D, entire worm, right ventro-lateral, right lateral, left lateral and left dorso-lateral views, respectively; arrows point to beginning of neuropodia; E – F, progressively closer views of the anterior end, ventral view; G – H, thorax, right and left lateral views, respectively; I – K, close ups of the anterior end, left dorso-lateral, ventral and right lateral views, respectively; L, posterior end, left dorso-lateral view; M, close up of the anterior end, left dorsolateral view; N, abdominal segments; arrows point to neuropodia; O, posterior end, right ventro-lateral view. Paratype AM W. 47363: P, entire worm, left lateral view (anteriorly); Q, thorax, left lateral view. Numbers refer to segments; ll = lower lip, P = basal part of prostomium; ul = upper lip. Scale bars: A = 0.6 mm; B – D, H = 0.5 mm; E, G = 0.4 mm; F, I – L, N = 0.2 mm; M, O = 0.15 mm; P = 1.5 mm; Q = 1 mm.

FIGURE 6. Amaeana hsiehae sp. nov., holotype ASIZW 0000935. A – B, progressively closer views of the notochaetae of segment 6; C – E, neurochaetae, segments 21 and two consecutive posterior ones, respectively. Scale bars: A = 30 µm; B = 15 µm; C – E = 7 µm.

FIGURE 7. Amaeana hsiehae sp. nov., paratype AM W. 47362. A – B, thorax right and left lateral views, respectively; C – F, anterior end, ventral, right lateral, dorsal and left lateral views, respectively; G, close up of the anterior end, ventral view; H, anterior end, dorsal view; I, anterior end, right ventro-lateral view. Numbers refer to segments; ll = lower lip, P = basal part of prostomium; ul = upper lip; * = distal part of prostomium. Scale bars: A – B, D, H = 200 µm; C, F = 100 µm; E = 150 µm; G, I = 70 µm.

FIGURE 17. Amaeana ellobophora sp. nov., paratype AM W. 7050. A, notopodium segment 8; B, tips of notochaetae from segment 8; C – D, progressively closer views of one neuropodium with protruding spines. Amaeana brasiliensis sp. nov., paratype MZUSP 2735. E – F, close up of notochaetae. Scale bars: A = 40 µm; B – C = 10 µm; D = 7 µm; E = 5 µm; F = 2 µm.

FIGURE 24. Chaetae. Amaeana yirrarn paratype AM W. 21888. A, notochaetae, segment 11. B, close up of the notochaetae from posterior row, segment 11. C, neurochaetae, segment 36. Amaeana dampierensis sp. nov. AM W. 47405. D, tips of notochaetae from posterior row, segment 7. E, neurochaetae, segment 29. Amaeana brasiliensis sp. nov. paratype MZUSP 2726. F – G, notochaetae, segment 4. H, neurochaetae, segment 34. I, neurochaetae, segment 36. Scale bars: A = 50; B – D, H – I = 5 µm; E = 10 µm; F = 40 µm; G = 2 µm.

FIGURE 28. Amaeana brasiliensis sp. nov. holotype MZUSP 2349. A – C, thorax, ventral, dorsal and left lateral views, respectively. D – E, close ups of the anterior end, ventral and dorsal views, respectively. F, anterior end, right lateral view. G, buccal tentacles. H, posterior end, right dorso-lateral view. Numbers refer to segments; li = lower lip; P = basal part of prostomium; PP = prostomial process; ls = upper lip. Scale bars: A – C, F, H = 1 mm; D – E, G = 0.5 mm.