Pectinaria ningalooensis Zhang & Hutchings 2019, n. sp

Autor: Zhang, Jinghuai, Hutchings, Pat
Rok vydání: 2019
Předmět:
DOI: 10.5281/zenodo.5670300
Popis: Pectinaria ningalooensis n. sp. Figs 32���34, Table 3 Material examined. Holotype: MV F161406, off Ningaloo South, West Australia, 22��00'14��� ��� 22��03'34���S 113��40���44��� ��� 113��43���44���E, 658 ��� 754 m, coll. Poore, Gary C., 10 Dec 2005. Description. Preserved specimen pale reddish in colour, conical in shape (Fig. 33A, B). Body length 36.8 mm including paleae and scaphe, width 6.1 mm at cephalic regions. Cephalic veil oval, with 24 smooth cirri on anterior margin and 1/3 of lateral margin (Figs 32A; 33A, D). Pair of ear-shaped lobes adjacent to both sides of dorsal base of cephalic veil (Figs 32A; 33D ��� E). Buccal tentacles broken, arising posterior to cephalic veil (Figs 32A; 33A, D). Operculum semicircular; dorsal and lateral margins well developed, smooth; ventral margin (opercular ridge) with 13 pairs of amber paleae, curved dorsally, acute with extended tips (Figs 32B; 33B). First pair of tentacular cirri extending beyond tips of paleae, with annuli, arising from connection of opercular margin and paleal ridge (Figs 32A ��� B; 33A ��� C). Pair of small ventral lappets present behind tentacular cirri near cephalic veil on segment 1 (Figs 32A; 33C). Ventral region of segment 1 covered by ventral lobes of segment 2 (Figs 32A; 33A, D). Second pair of tentacular cirri with annuli, extending beyond opercular anterior margin, on latero-median connecting ridge on segment 2, inserted more dorsally than 1 st pair of tentacular cirri (Figs 32B; 33C). Segment 2 with ventral lobes as pair 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 5�� as wide as ventro-lateral lobes (Figs 32A; 33A, C). Segment 2 without dorsal lobe (Figs 32B; 33B). Comb-like branchiae on segments 3 ��� 4, consisting of series of loose, flat lamellae (Figs 32B; 33C). Branchiae on segment 3 larger and inserted more ventrally than those of segment 4. Pair of small dorso-lateral glandular pads present adjacent to branchiae on segments 3 and 4 (Figs 32B; 33B ��� C). Distinct ventral glandular lobes present on segments 3 ��� 7, becoming progressively more lateral and broader on segments 3 ��� 5 (Figs 32A; 33A). Hump near branchiae on segment 4 not conspicuous. Segment 3 with pair of broad ventro-lateral lobes and mid-ventral lobe inserted more posteriorly, about 1/3 width of ventro-lateral lobes, separated from those by shallow grooves (Figs 32B; 33A). Segment 4 with pair of broad ventro-lateral lobes and mid-ventral lobe about 1/4 width of ventro-lateral lobes, separated from those by shallow grooves. Segment 5 with pair of ventro-lateral lobes and mid-ventral lobe about 1/5 width of ventro-lateral lobes, separated from those by shallow grooves. Segment 6 with pair of broad ventral lobes separated from each other by deep median notch. Segment 7 with pair of narrow ventro-lateral lobes about 1/4 of ventral width. Notopodia other than those of segment 1 which bear paleae, on segments 5 ��� 21 (17 pairs), each bearing two kinds of chaetae; one short and winged from anterior row, bordered with serrations along distal portion covered progressively with more spines from about middle to front of wing, on anterior surface; other long, stout and straight from posterior row, tapering to pointed tips, covered progressively with more spines from mid-anterior portion to tip, on anterior surface (Figs 32E ��� F; 33A ��� B; 34A ��� C). 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 2���4 longitudinal rows of major teeth, numbers of teeth per row decreasing from centre to sides, up to eight per row (Figs 32D; 34D ��� E). Segment 21 with ventro-lateral lobes near notopodia. Scaphe long ovoidal, flattened dorsally; each lateral margin dorsally rolled with two anterior narrow lobes and four posterior rounded lobes; anterior lobes much larger, 4 th lobe largest with papillae, other lobes without dorsal cirri under margin of each lobe; dorsal margin of scaphe vestigial, with three posterior plates (Figs 32C; 33F ��� G). Anal flap short tongue with crenulated margin, without dorsal anal cirrus (maybe lost) (Figs 32C; 33F ��� H). Scaphal hooks three pairs, stout, amber, with pointed tips, distinctly curved dorsally, present between lateral and dorsal margins of scaphal (Figs 32C; 33F ��� G, I). Tube not retained. Methyl Green stained body distinctly green on cirri of cephalic veil, opercular rim, ventral lobes of segments 2���7, dorso-lateral pads of segments 3���4, ventro-lateral regions adjacent to neuropodia, ventro-lateral regions of segments 20���21, margins on 1���2 nd pair of lateral lobes of scaphe, dorsal margin fused of scaphe, dorsal region between segment 21 and scaphe, ventro-lateral regions on scaphe, and dorsum of anal flap (Fig. 33G, H). Distribution. West Australia (Fig. 1). Known only from type locality. Habitat. Found in depths of 658 ��� 754 m. Etymology. The species is named ���ningalooensis��� as the species is collected from off Ningaloo South. Remarks. Pectinaria ningalooensis n. sp. can be distinguished by the following characters: 13 pairs of paleae with extended pointed tips; segment 2 without dorso-lateral lobes; segments 3 ��� 4 with dorso-lateral glandular pads; segment 6 without continuous papillae on ventral lobes; anal flap short with crenulated margin; one enlarged tooth and 2 ��� 4 longitudinal rows of major teeth on uncini; three pairs of stout scaphal hooks, with distinctly curved tips; dorsal margin of scaphe vestigial (Table 3). Pectinaria ningalooensis n. sp. is very similar to the Australian species P. kanabinos as they both have an anal flap with cirri, few scaphal hooks with distinctly bent tips. Pectinaria ningalooensis n. sp. differs from P. kanabinos which has one enlarged major tooth on the middle of uncini and 2 ��� 4 longitudinal rows of major uncinial teeth, anal flap short, dorsal margin of scaphe vestigial, three pairs of stout scaphal hooks, whereas P. kanabinos has four longitudinal rows of major teeth, anal flap slender and elongated, dorsal margin of scaphe well developed, and 2 ��� 5 pairs of small scaphal hooks. They also differ in their ecology, Pectinaria kanabinos occurs in shallow waters and estuaries whereas P. ningalooensis n. sp. is known only from deeper waters.
Published as part of Zhang, Jinghuai & Hutchings, Pat, 2019, A revision of Australian Pectinariidae (Polychaeta), with new species and new records, pp. 1-70 in Zootaxa 4611 (1) on pages 59-62, DOI: 10.11646/zootaxa.4611.1.1, http://zenodo.org/record/3229987
Databáze: OpenAIRE
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