Pectinaria lizhei, 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 : 41-50

Pectinaria lizhei n. sp.

Figs 17 ; 23–29 .

Material examined. Holotype: SCSMBC030897 (tissue sample sequenced), complete, Eyu Island, Xiamen Fujian Province, 118°10'33.6"E 24°35'14.6"N, intertidal, muddy sand, coll. J. Zhang & D. Yang, May 2019 . Paratypes: SCSMBC030901, SCSMBC030902, and SCSMBC030903 (tissue sample sequenced), 3 specs complete, Xianshan Harbor , Zhejiang Province, 121°27'44.9"E 29°27'29.8"N, 7.5 m, muddy sand, coll. Y. Liao, Aug 2019 . SC- SMBC030898 (tissue sample sequenced), 1 spec. complete, Eyu Island, Xiamen Fujian Province, 118°10'33.6"E 24°35'14.6"N, intertidal, muddy sand, coll. J. Zhang & D. Yang, May 2019 . SCSMBC030899(mounted for SEM) and SCSMBC030900, 2 specs complete, Eyu Island, Xiamen Fujian Province, 118°10'33.6"E 24°35'14.6"N, intertidal, muddy sand, coll. J. Zhang & D. Yang, May 2018 . SCSMBC030904, SCSMBC030905, and SCSMBC030906 (tissue sample sequenced), 3 specs complete, Guizhou Island, Daya Bay , Guangdong Province, 114°47'11.3"E 22°49'04.3"N, intertidal, muddy sand, coll. D. Yang, Apr 2021 .

Non type material examined. TIO908SPRFJMJK549(551), 1 spec. complete, greated distorted, East China Sea, Fujian Province, 120°07'30.0"E 25°52'48.0"N, 44 m, mud, coll. Third Ocean Institute, Ministry of Natural and Resources Yanping 2, Apr 2007 sta. MJK549(551). SCSMBC030907, 1 spec. complete, but with distorted body, Daya Bay , northern South China Sea, Guangdong Province, 113°45'35.0"E 22°25'09.0"N, 23 m, mud, coll. J. Zhang & Y. Gao, Dec 2019 , sta. SZ07. SCSMBC030908, 1 spec. complete, distorted, Hainan Island , South China Sea, 108°34'27.6"E 21°39'25.2"N, 9.7 m, mud, coll. J. Zhang, Aug 2015 , sta. D02. SCSMBC030909, 1 spec. complete, distorted, Hainan Island , South China Sea, 108°34'27.6"E 21°39'25.2"N, 9.7 m, mud, coll. J. Zhang, Aug 2015 , sta. D02. TIO908 SUMST09 H11, 1 spec. complete, Beibu Gulf , South China Sea, 109°05'43.0"E 18°17'18.0"N, 20 m, mud, coll. Xiamen University Experiment 2, Aug 2006 , sta. H11. SCSMBC030910, 1 spec. complete, Beibu Gulf , northern South China Sea, 109°11'43.0"E 18°10'42.0"N, 15 m, mud, coll. G. Liu, Aug 2018 .

Description. Preserved specimen pale in colour, conical in shape ( Figs 23A–C ; 25A–B ; 26A–B ). Body length 9.9–31.1 mm (holotype 16.4 mm) including paleae and scaphe, width 2.2–7.0 mm (holotype 2.4 mm) at cephalic regions.

Cephalic veil oval, free from operculum, with 12–21 smooth cirri (holotype 12) on anterior and lateral margins ( Figs 23E, G ; 25D ; 26D ). Pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil ( Fig. 26D, F ). Buccal tentacles long with long mid-groove, arising from posterior to cephalic veil, extending beyond margin of cephalic veil ( Figs 23E, G ; 25D ; 26D, H ).

Operculum semicircular; dorsal and lateral margins well developed, smooth; ventral margin (opercular ridge) with 10–16 pairs of golden paleae (holotype left 12, right 13), curved dorsally, acute with extended tips ( Figs 23F ; 25C ; 26C ).

First pair of tentacular cirri extending beyond paleae, with annuli, arising from connection of opercular margin and paleal ridge ( Figs 23E ; 25C–D ; 26C–D ). Pair of small ventro-lateral lappets present behind tentacular cirri, near cephalic veil, on segment 1 ( Figs 23E, G ; 25D ; 26C–D ). Ventral region of segment 1 covered by ventral lobes of segment 2 ( Figs 23E ; 25B ; 26D ).

Second pair of tentacular cirri almost same size with 1 st pair of tentacular cirri, extending beyond opercular anterior margin, with annuli, on latero-median connecting ridge on segment 2, inserted more dorsally than 1 st pair of tentacular cirri ( Figs 23E ; 25D ; 26C ). Pair of narrow ventro-lateral lobes and pair of broad ventral lobes on segment 2; ventro-lateral lobes connected with 2 nd pair of tentacular cirri, separated by narrow groove; ventral lobes smooth about 4x width of ventro-lateral lobes, separated by a little narrow groove. Dorsal lobe absent on segment 2 ( Figs 23F–G ; 25C ; 26C ).

Comb-like branchiae on segments 3–4, consisting of series of dense, flat lamellae. Branchiae on segment 3 larg- er and inserted more ventrally than those of segment 4 ( Figs 23E, G ; 25D ; 26C, I–J ). Pair of dorso-lateral glandular pads present adjacent to branchiae on segments 3 and 4; dorso-lateral glandular pads on segment 3 more developed than those of segment 4 ( Figs 23F–G ; 25C–D ; 26C ).

Distinct ventral glandular lobes present on segments 3–6, becoming progressively more lateral and broader on segments 3–5 ( Figs 23E, G ; 25D ; 26D ). Segment 3 with broad ventral lobe with shallow mid indentation about 1/5 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 more acute hump off mid ventral lobe; mid-ventral lobe almost same width as ventro-lateral lobe, with 5–6 continuous triangular lappets, lappets on corners of mid-ventral lobe larger and more acute than others ( Figs 23E, G–H ; 25D–E ; 26G ). Segment 5 with pair of ventro-lateral lobes and pair of mid-ventral lobes about 1/6 width of ventro-lateral lobes, separated by shallow grooves. Segment 6 with pair of ventro-lateral lobes and mid-ventral lobe, mid-ventral lobe more posterior about 1/7 width of ventro-lateral lobes, separated by shallow grooves.

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 ( Figs 27A–G ; 28A–D ). 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, 2–3 longitudinal rows of major teeth, each with about seven teeth ( Figs 27A, H–K ; 28A, E–G ). Segment 21 with pair of broad lateral lobes without chaetae, each lateral lobe with a transverse row of continuous numerous lappets, size of lappets decreasing from ventrum to dorsum ( Figs 24A–D ; 25F ; 26E ).

Scaphe long ovoidal, flattened dorsally; with five pairs of lobes on lateral-posterior margin included three pairs of anterior narrow lobes, 4 th pair relatively broad lobe, and pair of posterior rounded lobes with continuous cirri on lateral-posterior margins, 1 st cirrus on lateral margin of most posterior lobes larger than following cirri ( Figs 24A–C ; 25F ; 26E ). Anal flap long tongue-shaped, with numerous lappets or cirri on lateral-posterior margin; with long, thin mid-dorsal anal cirrus ( Figs 24A–C, E ; 25F ; 26E, K ). Scaphal hooks 3–7 pairs (holotype 6 pairs), amber in colour, hooked, distinctly curved dorsally, with acute tip, arranged in a straight row almost 45° angle to dorsal margin of scaphe ( Figs 24F ; 25G ; 26L ). Dorsal margin of scaphe smooth, slightly arched dorsally.

Tube ice-cream shape, made of sand, shell and sediment ( Figs 23D ; 29B–C ).

Methyl Green stained body distinctly green on cirri of cephalic veil, ventral-lateral lappets on segment 1, 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 23–25 ).

Type locality. Xiangshan Bay and Xiamen Island of East China Sea. Daya Bay , northern South China Sea ( Fig. 17 ) . Additional material collected from Beibu Gulf , northern South China Sea .

Habitat. Collected in muddy or muddy sand sediment from intertidal areas to shallow waters ( Fig. 29 ).

Etymology. The species is named after the first name of one of collectors for Professor Lizhe Cai and his student Deyuan Yang who provided us some material, including the holotype from Xiamen, Fujian Province and Daya Bay, Guangdong Province. Prof. Cai works at the the University of Xiamen, and makes a significant contribution to the study of the ecology of marine benthos in China.

Remarks. The new species Pectinaria lizhei n. sp. can be identified by the following characters: cephalic veil free from operculum, dorsal and lateral margins of operculum smooth, branchiae present on segments 3–4, midventral lobe of segment 4 almost equal width with ventro-lateral lobe and with 5–6 continuous triangular lappets, capillary notochaetae on segments 5–20, neurochaetae (uncini) on segments 8–20, with more than one longitudinal row of major teeth on uncinus. Pectinaria lizhei n. sp. is very similar to P. dayaensis n. sp. and P. xiukaii n. sp. in terms of the scaphal characters with continuous cirri on lateral-posterior margins on the posterior lobes of scaphe and numerous lappets or cirri on margin of anal flap. They can be separated by the mid-ventral lobe on segment 4, which in P. lizhei n. sp. is broad and almost the same width as the ventro-lateral lobe and has 5–6 continuous triangular lappets; segment 4 of P. dayaensis n. sp. has a broad mid-ventral lobe almost equal or much broader than ventro-lateral lobe, and with a pair of papillae at corners; whereas segment 4 of P. xiukaii n. sp. has a narrow midventral lobe about 1/2 width of ventro-lateral lobes, and with a pair of papillae at corners. Pectinaria lizhei n. sp. can be easily distinguished from P. torquata ( Zhang & Qiu, 2017) , which has a distinct complete dorsal lobe on segment 2, whereas P. lizhei n. sp. lacks this lobe. Pectinaria lizhei n. sp. differs from P. antipoda Schmarda, 1861 and P. papillosa Caullery, 1944 which have capillary notochaetae on segments 5–21, whereas P. lizhei n. sp. has capillary notochaetae on segments 5–20. The numbers of paleae, cirri on cephalic veil, and number of scaphal hooks of P. lizhei n. sp. increase with body size, but not significantly ( Fig. 30 ).

Figures

FIGURE 17. Map illustrating the distribution of Pectinaria torquata Zhang & Qiu, 2017, P. dayaensis n. sp., P. lizhei n. sp. and P. xiukaii n. sp. in the coastal waters of China

FIGURE 23. Pectinaria lizhei n. sp. Methyl Green stained body of Holotype (SCSMBC030897): A. Ventral view of entire body; B. Dorsal view of entire body; C. Lateral view of entire body; D. Tube; E. Ventro-lateral view of anterior end; F. Dorsal view of anterior end; G. Lateral view of anterior end; H. Ventral view of segment 4. Abbreviations: br, branchiae; bt, buccal tentacles; cv, cephalic veil; dlp, dorso-lateral pad; lh, lateral hump; op, operculum; or, opercular rim; p, paleae; s, segment; tc, tentacular cirri; vl, ventral lappet.

FIGURE 24. Pectinaria lizhei n. sp. Methyl Green stained posterior end of body of Holotype (SCSMBC030897): A. Dorsal view of posterior end; B. Lateral view of posterior end; C. Ventral view of posterior end; D. Lateral lobe on segment 21; E. Anal flap; F. Scaphal hooks. Abbreviations: ac, anal cirrus; af, anal flap; an, anus; nep, neuropodium; s, segment; sc, scaphe; sh, scaphal hooks.

FIGURE 25. Pectinaria lizhei n. sp. Methyl Green stained body of Paratype (SCSMBC030900): A. Lateral view of entire body; B. Ventral view of entire body; C. Dorsal view of anterior end; D. Lateral view of anterior end; E. Ventral view of segments 4; F. Lateral view of posterior end; G. Scaphal hooks. Abbreviations: ac, anal cirrus; af, anal flap; br, branchiae; bt, buccal tentacles; cv, cephalic veil; dlp, dorso-lateral pad; lh, lateral hump; nep, neuropodium; op, operculum; or, opercular rim; p, paleae; s, segment; sc, scaphe; tc, tentacular cirri; vl, ventral lappet.

FIGURE 26. Pectinaria lizhei n. sp. Paratype (SCSMBC030899), under the SEM: A. Ventro-lateral view of entire body; B. Dorso-lateral view of entire body; C. Lateral view of anterior end; D. Ventral view of anterior end; E. Ventral view of posterior end; F. Close up of lateral region between cephalic veil and segment 1. G. Ventral view of segments 3–4; H. Close up of buccal tentacle; I. Close ups of branchial lobes; J. Dorsal view of left branchiae; K. Anal flap; L. Close ups of scaphal hooks; M. Internal structure of scaphal hooks. Abbreviations: ac, anal cirrus; af, anal flap; br, branchiae; bt, buccal tentacles; cv, cephalic veil; dlp, dorso-lateral pads; lel, lateral ear-shaped lobe; nep, neuropodium; op, operculum; or, opercular rim; p, paleae; s, segment; sc, scaphe; tc, tentacular cirri; vl, ventral lappet.

FIGURE 27. Pectinaria lizhei n. sp. chaetae on anterior segments of Paratype (SCSMBC030899), under the SEM: A. Parapodia on segments 7–9; B–G. Close ups of notochaetae on segment 9; H. Dorsal uncini of neuropodia on segment 9; I. Median uncini of neuropodia on segment 9; J–K. Ventral uncini of neuropodia on segment 9. Abbreviations: nec, neurochaetae; s, segment.

FIGURE 28. Pectinaria lizhei n. sp. chaetae on posterior segments of Paratype (SCSMBC030899), under the SEM: A. Parapodia on segments 18–20; B–D. Close ups of notochaetae on segment 9; E. Ventral uncini of neuropodia on segment 18; F. Median uncini of neuropodia on segment 18; G. Dorsal uncini of neuropodia on segment 18. Abbreviations: noc, notochaetae; s, segment.

FIGURE 29. Habitat from which Pectinaria lizhei n. sp. was collected at Eyu Island of Xiamen City, Fujian Province, China in May 2019.

FIGURE 30. Relationship between body width and body length, number of cirri on cephalic veil, number of pairs of paleae, number of pairs of scaphal hooks, for Pectinaria lizhei n. sp.