Amphictene lizardensis Wong & Hutchings, 2015

Zhang, Jinghuai & Hutchings, Pat, 2019, A revision of Australian Pectinariidae (Polychaeta), with new species and new records, Zootaxa 4611 (1), pp. 1-70 : 14-16

Amphictene lizardensis Wong & Hutchings, 2015

Fig. 7 , Table 1

Amphictene lizardensis Wong & Hutchings, 2015: 733 – 744 , figs 1 – 3.

Material examined. Australia, Queensland: AM W.47432 (Holotype) , AM W.47429 (Paratypes), 2 specs, Lizard Island, Watsons Bay , 14°39’26”S 145°27’03”E, 6.5 m, sand, coll. P.A. Hutchings & M. Capa, 28 Aug 2010 .

Additional material examined. Australia, Queensland: AM W.45850, 1 spec. Lizard Island, North Point, Mermaid Cove , 14°38’46”S 145°27’13”E, 8 – 12 m, coral rubble in sand, coll. M. Capa, M.T. Aguado & V.I. Radashevsky, 20 Aug 2013 . Papua New Guinea: AM W.32720, 1 spec., North Rasch Passage, Madang Lagoon , 5°09’S 145°49’E, 30 m, algal covered rubble, coll. J.D. Thomas, 16 May 1991 .

Description. Based on all specimens examined. Preserved specimen pale reddish in colour, small, conical in shape ( Fig. 7A – B ). Body length 3.2 – 6.5 mm (holotype 6.5 mm) including paleae and scaphe, width 0.6 – 1.3 mm (holotype 1.3 mm) at cephalic regions.

Cephalic veil oval, free from operculum, with 10 – 13 (holotype 11) smooth cirri on anterior and lateral margins ( Fig. 7A, C ). Pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil. Prostomial buccal tentacles with deep medial grooves and inserted ventrally to cephalic veil ( Fig. 7A, C ).

Operculum semicircular; with 15 – 19 (holotype 15) triangular lappets with cirri on dorsal and lateral margins; with 12 – 14 (holotype 14) pairs of golden paleae, curved dorsally, acute with extended tips; with small median papilla between both rows of paleae ( Fig. 7B, D – E ).

Segments 1 – 2 each with pair of tentacular cirri on lateral sides of body, with annuli, second pair inserted more dorsally ( Fig. 7C ). Pair of small ventral lappets present ventrally to tentacular cirri, near cephalic veil, on segment 1. Segment 2 with several lobes on margin of ventral region ( Fig. 7C ). Comb-like branchiae present on segments 3 – 4, first pair larger and inserted more ventrally ( Fig. 7C – D ). Segment 3 with pair of dorso-lateral pads. Segment 5 with transverse dorsal ridge ( Fig. 7A – B, D – E ). Ventral glandular lobes present on segments 3 – 6 ( Fig. 7C ).

Notopodia other than those of segment 1 which bear paleae, on segments 5 – 21 (17 pairs), each bearing two kinds of notochaetae. Neuropodia, 13 pairs on segments 8 – 20, each with slightly raised torus with a transverse row of uncini; each uncinus with U-shaped anterior peg embedded into torus, several rows of minor teeth, and 3 – 6 longitudinal rows of major teeth, each with 6 – 9 teeth ( Wong & Hutchings, 2015: fig. 3).

Scaphe wide ovoidal, flattened dorsally, divided into four anterior narrow lobes with triangular tips and two posteriorly rounded lobes on each lateral margin ( Fig. 7F – G ). Anal flap triangular, with smooth margin and short anal cirrus ( Fig. 7F – G ). Scaphal hooks 3 – 4 (holotype 3) pairs, broad, golden or yellow-brown, tips curved and pointed ( Fig. 7F – G ).

Methyl Green stained body distinctly green on ventral lobes of segments 2–6, dorso-lateral pads of segment 3, and dorsum of anal flap ( Fig. 7 A–C). Additionally, dorsum of segment 2 with transverse row of about four green dots ( Fig. 7 D–E).

Distribution. Lizard Island, Queensland ( Fig. 1 ); Madang, Papua New Guinea.

Habitat. Sandy substrates in shallow waters.

Remarks. We have expanded the description of this species and the diagnostic features of this species to include having pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil, pair of small ventral lappets on segment 1, and a dorsal ridge on segment 5 which is visible on all the specimens examined ( Wong & Hutchings, 2015: figs 1 – 3). Amphictene lizardensis is very similar to A. uniloba Hutchings & Peart, 2002 which has 3 – 4 pairs of scaphal hooks, but differs from A. uniloba which has four longitudinal rows of major uncinial teeth, blunt lobes on opercular margin, pair of dorso-lateral pads on segments 3–4 and lacking dorsal ridge on segment 5. In contrast, A. lizardensis has 3 – 6 longitudinal rows of major uncinial teeth, triangular lobes more acute on opercular margin, a dorsal ridge on segment 5, a small papilla between two rows of paleae and only one pair of dorso-lateral pads on segment 3. All the specimens of A. lizardensis are small between 2.8 – 5.7 mm long, whereas a specimen (AM W.32720) from Madang Lagoon, Papua New Guinea, is similar (3.2 mm long, 0.6 mm wide) and which we believe belongs to the same species, as it has 13 pairs of cirri of cephalic veil, 12 pairs of paleae, 15 sharply pointed triangular lobes on the opercular rim, a dorsal ridge on segment 5, a small median papilla between the two rows of paleae, as well as the shape of the scaphe being similar with a terminal cirri on the anal flap, and three pairs of distinctly curved scaphal hooks (Table 1) which therefore extends its geographical range to Papua New Guinea.

Figures

FIGURE 1. Distribution of the species of Amphictene, Lagis and Pectinaria in Australia.

FIGURE 7. Amphictene lizardensis Wong & Hutchings, 2015 Methyl Green stained body (AM W.45850): A. Ventro-lateral view of entire body; B. Dorso-lateral view of entire body; C. Ventral view of anterior end; D. Dorsal view of anterior end; E. Dorso-lateral view of anterior end; F. Lateral view of posterior end; G. Ventro-lateral view of posterior end. Abbreviations: ac, anal cirrus; af, anal flap; br, branchiae; bt, buccal tentacles; cv, cephalic veil; dlp, dorso-lateral pad; dr, dorsal ridge; mpo, median papilla of operculum; nec, neurochaetae; noc, notochaetae; op, operculum; or, opercular rim; p, paleae; s, segment; sc, scaphe; sh, scaphal hooks; tc, tentacular cirri; vl, ventral lappet.