Amphictene jianqingi, Zhang & Hutchings & Qiu, 2022

Zhang, Jinghuai, Hutchings, Pat & Qiu, Jian-Wen, 2022, Pectinariidae (Annelida, Polychaeta) from the coastal waters of China, with description of new species and new records, Zootaxa 5151 (1), pp. 1-74 : 12-13

publication ID	https://doi.org/ 10.11646/zootaxa.5151.1.1
publication LSID	lsid:zoobank.org:pub:135CC8D7-CAFA-4B23-9006-AB8613E982A0
DOI	https://doi.org/10.5281/zenodo.6630897
persistent identifier	https://treatment.plazi.org/id/039E87CF-FFFA-FFFD-C39A-F9D3BBBFFEC5
treatment provided by	Plazi
scientific name	Amphictene jianqingi
status	sp. nov.

Treatment

Amphictene jianqingi View in CoL n. sp.

Figs 1 View FIGURE 1 , 4–6 View FIGURE 4 View FIGURE 5 View FIGURE 6 .

Material examined. Holotype: SCSMBC030870 (tissue sample sequenced), complete, Daya Bay, northern South China Sea , Guangdong Province, 114°33'10.8"E 22°35'34.8"N, 11 m, mud, coll. J. Zhang, Y. Gao & K. Chen, Jun 2015, sta. D05 GoogleMaps . Paratype: SCSMBC030871, 1 spec. complete, mounted for SEM, collected from the same location and time as holotype GoogleMaps .

Description. Holotype, pale in colour after preservation, conical in shape ( Fig. 4A–B View FIGURE 4 ). Body length 39.1 mm including paleae and scaphe, width 5.4 mm at cephalic region.

Cephalic veil oval, free from operculum, with 12 smooth cirri on anterior and lateral margins ( Figs 4D View FIGURE 4 ; 5B View FIGURE 5 ). Pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil. Buccal tentacles arising from posterior to cephalic veil, long grooved lobes, extending to margin of cephalic veil ( Figs 4D View FIGURE 4 ; 5B View FIGURE 5 ).

Operculum semicircular; dorsal and lateral margins well developed, with three pairs of long lateral cirri and 17 ventral triangular lappets; ventral margin (opercular ridge) with left 9 and right 10 golden paleae, curved dorsally, acute with extended tips ( Figs 4C View FIGURE 4 ; 5A View FIGURE 5 ).

First pair of tentacular cirri extending beyond paleae, with annuli, arising from connection of opercular margin and paleal ridge ( Figs 4C–D View FIGURE 4 ; 5A–B View FIGURE 5 ). Pair of small ventro-lateral lappets present behind tentacular cirri, near cephalic veil, on segment 1 ( Fig. 5C View FIGURE 5 ). Ventral region of segment 1 covered by ventral lobes of segment 2 ( Figs 4D View FIGURE 4 ; 5B View FIGURE 5 ).

Second pair of tentacular cirri long, extending beyond opercular anterior margin, with annuli, on latero-median connecting ridge on segment 2, inserted more dorsally than 1 st pair ( Figs 4C View FIGURE 4 ; 5A, C View FIGURE 5 ). Pair of broad ventro-lateral lobes and a mid-ventral lobe on segment 2; ventro-lateral lobes with three continuous small papillae on the inner portion and a smooth lateral lobe about 1/3 width of ventro-lateral lobes; mid-ventral lobe more posterior with two lobes with many papillae, separated by shallow grooves ( Figs 4D View FIGURE 4 ; 5B View FIGURE 5 ). Dorsal lobe absent on segment 2 ( Figs 4C View FIGURE 4 ; 5A, C View FIGURE 5 ).

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 4C–D View FIGURE 4 ; 5A, C View FIGURE 5 ). Pair of dorso-lateral glandular pads smooth adjacent to branchiae on segment 3 ( Figs 4C View FIGURE 4 ; 5A, C View FIGURE 5 ). Dorso-lateral glandular pads absent on segment 4.

Distinct ventral glandular lobes present on segments 3–6, becoming progressively more lateral and broader on segments 3–5 ( Figs 4D View FIGURE 4 ; 5B View FIGURE 5 ). Segment 3 with broad ventral lobe, swelling and higher mid ventrally. Segment 4 with pair of humps near branchiae and pair of ventro-lateral lobes about equal width with hump, separated by shallow grooves. Segment 5 with pair of ventro-lateral lobes and mid-ventral lobe about 1/4 width of ventro-lateral lobes, separated from them by shallow grooves. Segment 6 with pair of ventro-lateral ventral lobe, and mid-ventral partions more posteriorly, separated by shallow groove ( Figs 4D View FIGURE 4 ; 5B View FIGURE 5 ).

Notopodia other than those of segment 1 which bear paleae, on segments 5–20 (16 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; posterior row with stout, long and straight, tapering to an acute tip chaetae, covered with spines from mid-anterior portion to tip, on anterior surface ( Fig. 6E–J View FIGURE 6 ). Neuropodia, 13 pairs on segments 8–20, each with raised torus with a transverse row of uncini; each uncinus with U-shaped anterior peg embedded into torus, several rows of minor teeth, two longitudinal rows of major teeth, each with about seven teeth ( Fig. 6A–D View FIGURE 6 ). Segment 21 with pair of major lateral lobes without chaetae ( Figs 4E–F, H View FIGURE 4 ; 5D, F View FIGURE 5 ).

Scaphe long ovoidal, flattened dorsally; with five pairs of lobes on lateral-posterior margin including two pairs of narrow anterior lobes with triangle tip and three pairs of posterior rounded lobes; with three pairs of dorsal cirri under margin of the last three pairs of lobes; the last lobe with smooth lateral-posterior margin and a lappet adjacent to mid-line ( Figs 4E–H View FIGURE 4 ; 5D–F View FIGURE 5 ; 6K–M View FIGURE 6 ). Anal flap round-leaf shaped, with smooth margin, with short anal cirrus (absent on paratype) ( Figs 6E–G, H View FIGURE 6 ; 7D–G View FIGURE 7 ). Scaphal hooks about 26 pairs, amber, spear-shaped, almost straight, with blunt tip, arranged in transverse row on dorsal margin of scaphe ( Figs 4E, I View FIGURE 4 ; 6N–O View FIGURE 6 ). A small rounded lobe on dorsal margin of scaphe in between rows of scaphal hooks ( Figs 4E, H–I View FIGURE 4 ; 5D View FIGURE 5 ; 6K View FIGURE 6 ).

Tube not collected.

Methyl Green stained body distinctly green on cephalic veil, ventral lobes of segments 2–6, base of 2 nd pair of tentacular cirri, dorso-lateral pads of segment 3, neuropodia, regions between segment 20 and scaphe, margins of scaphe, and the posterior ventral half of the scaphe ( Fig. 4A–B View FIGURE 4 ).

Distribution. Daya Bay, northern South China Sea ( Fig. 1 View FIGURE 1 ).

Habitat. Collected in mud in shallow water.

Etymology. The species is named after the first name of Jinghuai’s son Jianqing Zhang for he was a lovely boy and gave the senior author some moral support on the taxonomy of polychaetes.

Remarks. The new species Amphictene jianqingi n. sp. can be distinguished from other species of pectinariids by the following characters: cephalic veil free from operculum, with numerous cirri on margins; opercular margin with cirri or lappets; comb-like branchiae present on segments 3–4; dorso-lateral glandular pad smooth on segment 3; dorso-lateral glandular pads absent on segment 4; capillary notochaetae on segments 5–20; neurochaetae (uncini) on segments 8–20; dorsal cirri under lateral margin of the last three lobes on scaphe. The new species is very similar to A. alata Zhang, Zhang & Qiu, 2015 collected from the same locality and A. japonica ( Nilsson, 1928) from Japan, as all have capillary notochaetae on segments 5–20, neurochaetae (uncini) on segments 8–20, numerous scaphal hooks, but A. jianqingi n. sp. differs from A. alata and A. japonica by having dorsal cirri on the lateral margin of scaphe. Otherwise, dorso-lateral pads of A. jianqingi n. sp. are smooth on segment 3, whereas those of A. alata have a crenulated margin on segment 3. Amphictene cercusa Zhang & Hutchings, 2019 is the other species with dorsal cirri on the lateral margin of scaphe, but differs from the new species by having capillary notochaetae on segments 5–21, and crenulated posterior margin (cirri) on the last lobes of scaphe.