Amphictene undulata, Zhang & Hutchings, 2019

Zhang, Jinghuai & Hutchings, Pat, 2019, A revision of Australian Pectinariidae (Polychaeta), with new species and new records, Zootaxa 4611 (1), pp. 1-70: 23-27

publication ID

https://doi.org/10.11646/zootaxa.4611.1.1

publication LSID

lsid:zoobank.org:pub:178FED38-5FEA-417F-B5DC-807D943B641C

DOI

http://doi.org/10.5281/zenodo.5670291

persistent identifier

http://treatment.plazi.org/id/586F0669-FF9F-FF96-FF7B-F9A5BCCB28D7

treatment provided by

Plazi

scientific name

Amphictene undulata
status

n. sp.

Amphictene undulata   n. sp.

Figs 13–15 View FIGURE 13 View FIGURE 14 View FIGURE 15 , Table 1

Material examined. Australia, West Australia: Holotype: MV F151408, off Ningaloo North, Western Australia, 21°58'08–42”S 113°45’14–40”E, 726 – 732 m, coll. Poore, Gary C., 11 Dec 2005.  

Description. Holotype, preserved specimen pale reddish in colour, conical in shape ( Fig. 14A – B View FIGURE 14 ). Body length 38.8 mm including paleae and scaphe, width 7.3 mm at cephalic regions.

Cephalic veil oval, broken, free from operculum, with more than 50 smooth cirri on anterior margin and 2/3 of lateral margin, broken part with fine and thick cirri ( Figs 13B View FIGURE 13 ; 14C View FIGURE 14 ). Pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil. Long buccal tentacles with wide longitudinal grooves, arising posterior to cephalic veil ( Figs 13B View FIGURE 13 ; 14B – C View FIGURE 14 ).

Operculum semicircular; dorsal and lateral margin well developed, with about 40 small triangular lappets on undulating margin ( Figs 13A View FIGURE 13 ; 14A, E View FIGURE 14 ); ventral margin (opercular ridge) with 15 pairs of stout and amber paleae, curved dorsally, acute with extended tips ( Figs 13A View FIGURE 13 ; 14E View FIGURE 14 ).

First pair of tentacular cirri extending beyond tips of paleae, with several faint annuli at base, arising from connection of opercular margin and paleal ridge ( Figs 13A – B View FIGURE 13 ; 14C, E View FIGURE 14 ). Pair of small ventral lappets present behind tentacular cirri near cephalic veil, on segment 1 ( Figs 13B View FIGURE 13 ; 14C View FIGURE 14 ).

Second pair of tentacular cirri long, extending beyond opercular anterior margin, with several obscure annuli at base, on latero-median connecting ridge on segment 2, inserted more dorsally than 1 st pair of tentacular cirri ( Figs 13A View FIGURE 13 ; 14E View FIGURE 14 ). Segment 2 with ventral lobes as pairs of narrow ventro-lateral lobes separated by shallow grooves from base of 2 nd pair of tentacular cirri, and pair of broad mid-ventral lobes about twice as wide as ventro-lateral lobes, with slightly crenulated margin ( Figs 13B View FIGURE 13 ; 14C View FIGURE 14 ). Dorsal lobe absent on segment 2 ( Figs 13A View FIGURE 13 ; 14A, E View FIGURE 14 ).

Comb-like branchiae on segments 3 – 4, consisting of series of dense, flat lamellae. Branchiae on segment 3 larger and inserted more ventrally than those of segment 4 ( Figs 13A View FIGURE 13 ; 14B View FIGURE 14 ). Pair of small dorso-lateral glandular pads present adjacent to branchiae on segments 3 and 4 ( Figs 13A View FIGURE 13 ; 14A, E View FIGURE 14 ).

Distinct ventral glandular lobes present on segments 3 – 6, becoming progressively more lateral and broader on segments 3 – 5 ( Figs 13B View FIGURE 13 ; 14C View FIGURE 14 ). No hump visible near branchiae on segment 4. Segment 3 with broad ventral lobe, swelling and higher at mid-line. Segment 4 with pair of ventro-lateral lobes and mid-ventral lobe about 1/3 width of ventro-lateral lobes, separated from those by deep grooves. Segment 5 with pair of ventro-lateral lobes and midventral lobe about 1/5 width of ventro-lateral lobes, separated from those by shallow grooves. Segment 6 with pair of ventro-lateral lobes and narrow mid-ventral lobe about 1/6 width of ventro-lateral lobes, separated from those by shallow grooves ( Figs 13B View FIGURE 13 ; 14B – C View FIGURE 14 ).

Notopodia other than those of segment 1 which bear paleae, on segments 5 – 21 (17 pairs), each bearing two kinds of notochaetae; one winged from anterior row, bordered with serrations along distal portion, short, covered progressively with more spines from about middle to front of wing, on anterior surface; others stout, long and straight, tapering to an acute tip, covered progressively with more spines from mid-anterior portion to tip, on anterior surface ( Figs 13E View FIGURE 13 ; 14A – B View FIGURE 14 ; 15A – C View FIGURE 15 ). 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, one large tooth and two longitudinal rows of teeth, each with about seven teeth ( Figs 13G – F View FIGURE 13 ; 14A, F View FIGURE 14 ; 15D – F View FIGURE 15 ). Segment 21 with ventral lobe near each notopodium ( Figs 13D View FIGURE 13 ; 14F View FIGURE 14 ).

Scaphe long ovoidal, flattened dorsally; with five anterior pointed lobes and single posterior rounded lobe on lateral margin; without dorsal cirri under margin of each lateral lobe ( Figs 13C – D View FIGURE 13 ; 14A – B, F View FIGURE 14 ). Anal flap triangular, with smooth margin, with short anal cirrus. Scaphal hooks five pairs, amber, slightly curved dorsally, with pointed tips, present near dorsal margin ( Figs 13H View FIGURE 13 ; 14D, F View FIGURE 14 ).

Tube not retained.

Methyl Green stained body distinctly green on cirri of cephalic veil, ventral lobes of segments 2–6, base of 2 nd pair of tentacular cirri, dorso-lateral pads of segments 3–4, ventro-lateral regions adjacent to neuropodia, regions between segment 21 and scaphe, margins of scaphe, and ventro-lateral regions near posterior four pairs of lateral lobes on scaphe ( Fig. 14 View FIGURE 14 ).

Type Locality. NW of Western Australia ( Fig. 1 View FIGURE 1 ), currently only known from type locality   .

Habitat. Soft sediments from 726 – 732 m.

Etymology. The species is named from the Latin word “undulata” as opercular margin of the species is slightly undulated.

Remarks. The holotype of A. undulata   n. sp., has a damaged rim of the cephalic veil with numerous fine cirri on anterior-left margin which almost certainly represent regenerating cirri ( Figs 13B View FIGURE 13 ; 14C View FIGURE 14 ). Amphictene undulata   n. sp. is distinguished from all other species of Amphictene   by the following characters: slightly undulating dorsal and lateral margins of operculum; 15 pairs of paleae; and uncini with one enlarged tooth and two longitudinal rows of major teeth (Table 1). Amphictene undulata   n. sp. is very similar to A. uniloba Hutchings & Peart, 2002   , as they both have one enlarged medial tooth on each uncinus and almost rounded lobes on the opercular margin, but can be distinguished from A. uniloba   which has more longitudinal rows (3 – 4 rows) of major uncinial teeth, triangular lobes on opercular margin and distinctly curved scaphal hooks (Table 1).

MV

University of Montana Museum