Pectinaria xiukaii, 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 : 50-55

publication ID	https://doi.org/ 10.11646/zootaxa.5151.1.1
publication LSID	lsid:zoobank.org:pub:135CC8D7-CAFA-4B23-9006-AB8613E982A0
persistent identifier	https://treatment.plazi.org/id/039E87CF-FFC0-FFC7-C39A-FCFABD71FE99
treatment provided by	Plazi
scientific name	Pectinaria xiukaii
status	sp. nov.

Treatment

Pectinaria xiukaii n. sp.

Figs 17 View FIGURE 17 ; 31–34 View FIGURE 31 View FIGURE 32 View FIGURE 33 View FIGURE 34 .

Material examined. Holotype: SCSMBC030929, complete, Chang Island , Bohai Sea, Shangdong Province, 120°38'52.8"E 38°15'55.4"N, 28 m, muddy sand, coll. J. He & Y. Wang, Sep 2018, sta. DQ060 GoogleMaps . Paratypes: SC- SMBC030930 , 2 specs, complete, Chang Island , Bohai Sea , Province (Bo Sea), 120°38'52.8"E 38°15'55.4"N, 28 m, mud, coll. J. He, Y. Wang, Sep 2018, sta. DQ060. TIO908 GoogleMaps SUMST01 LDW007, 1 spec. complete, Bohai Sea , 121°05'48.0"E 40°23'44.0"N, 23 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Aug 2006, sta. LDW007. TIO908 GoogleMaps SUMST01 LDW039, 1 spec. complete, Bohai Sea , 120°45'56.0"E 40°19'30.0"N, 20 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Aug 2006, sta. LDW039. TIO908 GoogleMaps SUMST01 LDW031, 1 spec. complete, Bohai Sea , 121°51'46.0"E 40°17'02.0"N, 16.7 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Aug 2006, sta. LDW031. TIO908 GoogleMaps SUMST01 BH002, 1 spec. complete, Bohai Sea , 121°13'56.0"E 39°51'45.0"N, 24.5 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Aug 2006, sta. BH002. TIO908 GoogleMaps SUMST01 BH006, 1 spec. complete, Bohai Sea , 121°06'03.0"E 39°42'00.0"N, 31.4 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Aug 2006, sta. BH006. TIO908 GoogleMaps WINST01 B DH066, 1 spec. complete mounted for SEM, Bohai Sea , 119°26'47.0"E 39°21'31.0"N, 17 m, mud, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Jan 2007, sta. BDH066. TIO908 GoogleMaps SUMST01 BH018, 1 spec. complete, Bohai Sea , 120°15'00.0"E 39°00'00.0"N, 21.9 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Jul 2006, sta. BH018. TIO908 GoogleMaps SUMST01 BH026, 2 specs, complete, Bohai Sea , 120°15'00.0"E 38°45'00.0"N, 25.3 m, muddy sand, coll. Beihai Branch of State Oceanic Administration, China Marine Monitoring Vessel 17, Aug 2006, sta. BH026. TIO908 GoogleMaps AUTST02 C702, 1 spec. posteriorly incomplete, northern Yellow Sea , 122°10'17.0"E 38°54'40.4"N, 47 m, mud, coll. the study group of benthos, Ocean University of China, Oct 2007, sta. C702. TIO908 GoogleMaps SUMST02 B102, 1 spec. complete, Yellow Sea , 122°44'33.3"E 36°59'59.6"N, 32 m, sand, coll. the study group of benthos, Ocean University of China, Dongfanghong 2, Aug 2006, sta. B102 GoogleMaps .

Description. Preserved specimen pale or reddish in colour, conical in shape ( Figs 31A–C View FIGURE 31 ; 32A–B View FIGURE 32 ; 33A View FIGURE 33 ). Body length 9.1–28.5 mm (holotype 9.6 mm) including paleae and scaphe, width 1.1–4.5 mm (holotype 2.1 mm) at cephalic regions.

Cephalic veil oval, free from operculum, with 9–20 smooth cirri (holotype 11) on anterior and lateral margins ( Figs 31F–G View FIGURE 31 ; 32A View FIGURE 32 ; 33C View FIGURE 33 ). Pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil ( Fig. 33I View FIGURE 33 ). Buccal tentacles broad and short, with long mid-groove, arising from posterior to cephalic veil, extending to margin of cephalic veil ( Figs 31F–G View FIGURE 31 ; 32A View FIGURE 32 ; 33C View FIGURE 33 ).

Operculum semicircular; dorsal and lateral margins well developed, smooth; ventral margin (opercular ridge) with 10–13 pairs of golden paleae (holotype 13 pairs), curved dorsally, acute with extended tips ( Figs 31E–F View FIGURE 31 ; 32A–B View FIGURE 32 ; 33B–C View FIGURE 33 ).

First pair of tentacular cirri extending beyond paleae, with annuli, arising from connection of opercular margin and paleal ridge ( Figs 31E–G View FIGURE 31 ; 33B–C View FIGURE 33 ). Pair of small ventral-lateral lappets present behind tentacular cirri, near cephalic veil, on segment 1 ( Fig. 31F View FIGURE 31 ). Ventral region of segment 1 covered by buccal tentacles and ventral lobes of segment 2 ( Figs 31F View FIGURE 31 ; 32A View FIGURE 32 ).

Second pair of tentacular cirri almost same size as 1 st pair, extending beyond opercular anterior margin, with annuli, on latero-median connecting ridge of segment 2, inserted more dorsally than 1 st pair of tentacular cirri ( Figs 31G View FIGURE 31 ; 33B View FIGURE 33 ). Pair of broad smooth ventro-lateral lobes on segment 2, separated by deep mid-groove; each ventrolateral lobe with two continuous small lobes close to tentacular cirrus. Dorsal lobe absent on segment 2 ( Figs 31E View FIGURE 31 ; 32B View FIGURE 32 ; 33B View FIGURE 33 ).

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 31E–G View FIGURE 31 ; 33B View FIGURE 33 ). Pair of dorso-lateral glandular pads present adjacent to branchiae on segments 3 and 4, dorso-lateral glandular pads on segment 3 larger ( Figs 31E, G View FIGURE 31 ; 32B View FIGURE 32 ; 33B View FIGURE 33 ).

Distinct ventral glandular lobes present on segments 3–6, becoming progressively more lateral and broader on segments 3–5 ( Figs 31F–G View FIGURE 31 ; 32A, C View FIGURE 32 ; 33C View FIGURE 33 ). Segment 3 with broad ventral lobe with shallow median indentation about 1/7 width of ventral lobe. Segment 4 with pair of ventro-lateral lobes and a mid-ventral lobe, separated from these by shallow groove; each ventro-lateral lobe with a large lateral hump adjacent to branchia and a relatively small and acute hump off mid-ventral lobe; mid-ventral lobe narrow about 1/2 width of ventro-lateral lobe, short rectangular, with pair of papillae adjacent to corner ( Figs 31J View FIGURE 31 ; 32C–D View FIGURE 32 ; 33C, F View FIGURE 33 ). 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 lobes, separated by mid shallow groove.

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; others stout, long and straight, tapering to an acute tip, covered progressively with more spines from mid-anterior portion to tip, on anterior surface ( Fig. 34A–E View FIGURE 34 ). 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, 3–4 longitudinal rows of major teeth, each with about seven teeth ( Fig. 34A–B, F–K View FIGURE 34 ). Segment 21 with pair of broad lateral lobes without chaetae, each lateral lobe with a transverse row of continuous numerous lappets, size of lappets decreases from ventrum to dorsum ( Figs 31H–I, L View FIGURE 31 ; 32F–G View FIGURE 32 ; 33E View FIGURE 33 ).

Scaphe wide ovoidal, flattened dorsally; with five pairs of lobes on lateral-posterior margin including four pairs of anterior narrow lobes with triangular tip and last pair with rounded lobes with continuous cirri on lateral-posterior margins, first cirrus on lateral margin of last lobes larger than the following ones ( Figs 31H–I, L View FIGURE 31 ; 32F–H View FIGURE 32 ; 33D–E, G–H, J View FIGURE 33 ). Anal flap long tongue-shaped, with numerous cirri on lateral-posterior margin, with long, thin mid-dorsal anal cirrus ( Figs 31K View FIGURE 31 ; 32H View FIGURE 32 ; 33J View FIGURE 33 ). Scaphal hooks 3–6 pairs (holotype 6 pairs), amber, hooked, distinctly curved dorsally, with acute tips, arranged in almost perpendicular row to dorsal margin of scaphe ( Figs 31I, L View FIGURE 31 ; 32E View FIGURE 32 ; 33K View FIGURE 33 ). Dorsal margin between rows of scaphal hooks smooth, arched dorsally.

Tube ice-cream shape, consisted by sand, shell and sediment fragments held together by cement ( Fig. 31D View FIGURE 31 ).

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 segments 3–4, ventral region of some neuropodia, regions between segment 20 and scaphe, ventral regions of scaphe, and dorsum of anal flap ( Figs 31–32 View FIGURE 31 View FIGURE 32 ).

Type locality. Bohai Sea , northern Yellow Sea ( Fig. 17 View FIGURE 17 ) .

Habitat. Collected in muddy or muddy sand sediment in shallow water.

Etymology. The species is named after the first name of one of collectors for Xiukai Li, who collected three complete specimens (including holotype) with his team from Chang Island, Shandong Province.

Remarks. The new species Pectinaria xiukaii n. sp. can be identified by the following characters: cephalic veil free from operculum, dorsal and lateral margins of semicircular operculum smooth, branchiae present on segments 3–4, mid-ventral lobe of segment 4 narrow about 1/2 width of ventro-lateral lobe and with a pair of papillae adjacent to corner, capillary notochaetae on segments 5–20, neurochaetae (uncini) on segments 8–20, more than one longitudinal row of major teeth on uncinus. The new species can be easily distinguished from P. torquata Zhang & Qiu, 2017 as P. xiukaii n. sp. lacks a dorsal lobe on segment 2, whereas P. torquata has a distinct complete dorsal lobe on segment 2. Pectinaria xiukaii n. sp. differs from P. antipoda Schmarda, 1861 and P. papillosa Caullery, 1944 as P. xiukaii n. sp. has capillary notochaetae on segments 5–20, while the other two species have capillary notochaetae on segments 5–21. Pectinaria xiukaii n. sp. is similar to P. dayaensis n. sp. and P. lizhei n. sp., but they can be distinguished as outlined in the previous Remarks for P. dayaensis n. sp. and P. lizhei n. sp. The number of cirri on the cephalic veil of P. xiukaii n. sp. increases significantly with body size ( Fig. 35 View FIGURE 35 ). The number of pairs of paleae, and pairs of scaphal hooks of Pectinaria xiukaii n. sp. also increases with body size, but not significantly ( Fig. 35 View FIGURE 35 ).