Amaeana ellobophora, 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 : 29-33

Amaeana ellobophora sp. nov.

Figures 1 , 15 , 16 and 17 A–E

Amaeana trilobata .— Hutchings 1977 (in part): 9. — Hutchings & Glasby 1986 (in part): 321–323, Fig. 1 f–i.

Material examined. Holotype AM W.7055 (coll. Moreton Island, southwest of Tangalooma Point): incomplete, in good state of preservation, with thorax plus ~16 abdominal segments. Paratypes: AM W.5065 (Peel Island, 1.6 km south east of South West Rocks, 27°31'48"S, 153°21'E): incomplete, in good state of preservation, 35 mm long, 5 mm maximum width, thorax plus 26 abdominal segments. AM W.5066 (coll. Peel Island, 2.4 km south of South West Rocks, 27°30'S, 153°21'E): incomplete, in good state of preservation, 20 mm long, 4 mm maximum width, thorax plus ~18 abdominal segments. AM W.5069 (coll. Peel Island, 1.6 km south east of South West Rocks, 27°31'48"S, 153°21'E): 2 specimens, both incomplete, in good state of preservation, one 25 mm long, 4 mm maximum width, thorax plus ~14 abdominal segments, another 30 mm long, 4 mm wide, thorax plus ~20 abdominal segments. AM W.7050 (coll. Moreton Island, southwest of Tangalooma Point, 27°12'S, 153°22'E, Sep 1972): complete, in good state of preservation, mounted on SEM stub. AM W.10341 (coll. Calliope River, north of Gladstone, 23°51'S, 151°10'E, 7.Oct.1975): incomplete, in good state of preservation, with four egg cocoons attached to mid-dorsal prostomial process ( Fig. 1 A–B); slides: notochaetae, segment 10; anterior neuropodium; posterior neuropodium.

Additional material examined. AM W.201648: coll. Queensland, Calliope River, near Gladstone, 23°51'S, 151°10'E, 1974. AM W.199467: Queensland, Gladstone area, 23°50'S, 151°15'E, 1974.

Type locality. Australia, Queensland, Moreton Bay, Southwest of Tangalooma Point, 27°12'S, 153°22'E, 4– 6 m.

Description. Holotype incomplete specimen, 16 mm long, 3 mm wide at segment 7, maximum width of body.

Prostomium at base of upper lip, both basal and distal parts developed, basal part as thickened crest, distal part with large, flaring lobes and also raised rounded mid-dorsal process; prostomium covering segment 1 laterally and terminating laterally to lower lip, near mouth ( Figs 15 A–E, G–J; 16A–G). Few buccal tentacles remaining, uniformly cylindrical and distally spatulate; modified type of tentacles missing or lacking.

Peristomium restricted to lips, upper lip elliptical, higher than broad, folded into three lobes; relatively large, button-like lower lip, rounded ( Figs 15 A–E, G–J; 16A–G). Body anteriorly swollen from segment 3, progressively broader until segments 7–8, then progressively narrower until segment 10, and of relatively uniform width until segment 12, tapered on segments 13–18, then of uniform width through posterior body, tapering to pygidium ( Figs 15 A–K; 16A–G); achaetous gap between termination of notopodia and beginning of neuropodia, corresponding to segments 13–17, half to 2/3 length of all region with notopodia, with poorly marked segmentation and fragile, with thin body wall dorsally ( Figs 15 A–B; 16A–C).

Segments biannulated, segment 1 short, visible dorsal and ventrally, laterally covered by expanded prostomium; segment 2 narrower and shorter than following segments, with large pentagonal mid-ventral shield at beginning of mid-ventral groove, extending anteriorly through segment 1 until near ventral edge of lower lip ( Figs 15 A–C, E–I; 16A–G, I–J). Ventrum highly glandular, covered on small papillae, arranged in paired ventro-lateral pads on segments 2–12; papillae larger and more numerous on anterior segments, covering segmental annulations, papillae progressively less numerous and conspicuous on segments 10–12, then smooth body wall, with paired longitudinal crests bordering mid-ventral groove through posterior body ( Figs 15 A–B, D–F, H–K; 16B–D, G–H, J).

Notopodia extending through 10 segments, until segment 12; elongate, cylindrical notopodia, with equal sized lobes and elongate and distally blunt tips ( Figs 15 A–E, G–J; 16A–E, H). Acicular notochaetae, nearly alimbate capillaries in both rows, wings not visible under higher magnifications of light microscopy ( Fig. 15 L), as short and fine hairs under SEM ( Fig. 17 A–B).

Neuropodia present from segment 18, laterally to mid-ventral groove, on outer margins of longitudinal crests ( Figs 15 A–B, F, K; 16J). Neurochaetae as thin, distally tapered spines, with thinner knob-like tip, ~8 spines on anterior neuropodia, up to ~11 on posterior ones, ( Figs 15 M–O; 17C–D).

Nephridial and genital papillae at anterior bases of all notopodia, all short and difficult to distinguish from glandular pads papillae ( Fig. 15 E, H, J). Pygidium with rounded ventral papilla ( Fig. 16 I–J).

Biology. Paratype AM W.10341 with four egg cocoons of different sizes, attached to mid-dorsal prostomial process ( Fig. 1 A–B). Such brooding method has never been observed in any other species of Terebelliformia.

Remarks. Amaeana ellobophora sp. nov., is another species with 10 pairs of notopodia previously identified as A. trilobata ( Hutchings 1977; Hutchings & Glasby 1986). It differs from that species, however, in having an achaetous gap of 5 segments between termination of notopodia and beginning of neuropodia, with neuropodia beginning on segment 18 and bearing 8–11 spines each, while in A. trilobata , as discussed above, neuropodia begin from segment 16, so the achaetous gap extends only for 3 segments, and bear 4–5 spines each.

Five other species of Amaeana have 10 pairs of notopodia, A. apheles , A. angulus sp. nov., A. crassispinulata sp. nov., A. hsiehae sp. nov., and A.ellobophora sp. nov. Members of A. apheles differ from those of A. ellobophora sp. nov., in having 9–10 achaetous segments between termination of notopodia and beginning of neuropodia, with neuropodia from segments 21–22, each with 1–2 stout, distally sharp spines.

Amaeana angulus sp. nov., described above, has ventral pads extending to segment 15, while in A. ellobophora sp. nov. they do not extend beyond segment 12. In addition, members of A. angulus sp. nov. have an achaetous gap of 8 segments between termination of notopodia and beginning of neuropodia, and neuropodia begin from segment 21 and bear 4–5 spines each.

In A. crassispinulata sp. nov, also described herein, the achaetous gap between termination of notopodia and beginning of neuropodia also extends for 8 segments and each neuropodium has a single spine, basally bulbous and distally truncate.

Finally, members of A. hsiehae sp. nov., also described above, differ from A. ellobophora sp. nov., in having pinnate chaetae in both rows of notochaetae, while in A. ellobophora sp. nov., only acicular chaetae are present. In addition, the achaetous gap between termination of notopodia and beginning of neuropodia extends for 7 segments among members of A. hsiehae sp. nov., with neuropodia beginning from segment 20 and bearing 2–3 spines each.

Etymology. The specific name refers to the cocoons found in some individuals, a character which has not been found in any other species examined to date. The epithet comes from “ellobos”, Greek word for “pod”, plus “phoras”, greek word for “bearer”.

Figures

FIGURE 1. Amaeana ellobophora, paratype 1 AM W. 10341, with egg cocoons: A, entire worm, dorsal view. B, anterior end, dorsal view. Scale bars: A = 0.5 mm; B = 0.3 mm.

FIGURE 15. Amaeana ellobophora sp. nov., holotype AM W. 7055. A – B, entire worm, ventral and right lateral views (anteriorly), respectively; arrows point to first neuropodium. C – E, anterior end, dorsal, ventral and right dorso-lateral views, respectively. F, posterior end of fragment. G – J, close ups of the anterior end, dorsal, left lateral, ventral and right lateral views, respectively; arrows point to nephridial / genital papillae. K, close up of the posterior end of fragment. L, notochaetae, segment 10; M, anterior neurochaetae. N – O, progressively closer views of the neurochaetae of a posterior neuropodium. Numbers refer to segments; ll = lower lip, P = basal part of prostomium; PP = mid-dorsal prostomial process; ul = upper lip; * = distal part of prostomium. Scale bars: A – B = 1 mm; C – E = 0.4 mm; F = 0.5 mm, G – I, K = 0.2 mm; J = 0.3 mm; L = 50 µm; M = 40 µm; N = 30 µm; O = 10 µm.

FIGURE 16. Amaeana ellobophora sp. nov., paratype AM W. 7050. A – C, thorax, dorsal, ventral and right lateral views, respectively. D, close up of the anterior end, right lateral view. E – F, progressively closer close ups of the anterior end, dorsal views. G, close up of the anterior end, ventral view. H, notopodia, segments 7 – 10; arrows point to genital papillae. I – J, posterior end, dorsal and left lateral views, respectively. Numbers refer to segments; ll = lower lip, P = basal part of prostomium; PP = mid-dorsal prostomial process; ul = upper lip; P * = distal part of prostomium. Scale bars: A – C = 0.3 mm; D, J = 0.2 mm; E = 0.15 mm; F – H = 0.1 mm; I = 60 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.