Diversity and biogeography of scale worms in the subfamily Lepidonotopodinae (Annelida: Polynoidae) from Indian Ocean hydrothermal vents with descriptions of four new species Author Han, Yuru Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China Author Zhou, Yadong Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China & Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China yadong_zhou@sio.org.cn Author Chen, Chong X-STAR, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2 - 15 Natsushima-cho, Yokosuka, Kanagawa Prefecture 237 - 0061, Japan Author Wang, Yueyun Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China text Zoological Journal of the Linnean Society 2024 2023-10-17 201 2 290 304 http://dx.doi.org/10.1093/zoolinnean/zlad140 journal article 10.1093/zoolinnean/zlad140 0024-4082 13220046 F6E6171-16B7-43DA-A064-6D13AFD99FC1 Levensteiniella pettiboneae sp.nov. ( Fig. 2 ) ZooBank registration: urn:lsid:zoobank.org:act: 73D3C46A-9708-436F-8C70-022D17950010 . Polynoidae indet. #4— Zhou et al. 2022 . Diagnosis: Moderate-sized Levensteiniella with oval prostomium; iridescent elytra 11 pairs, with micropapillae on posterior and lateral border; 10 pairs of inconspicuous rounded ventral papillae on segments 11–20 on female; two pairs of long ventral papillae on segments 11 and 12 on male. Figure 2. Levensteiniella pettiboneae sp. nov. Holotype (RSIO35217, female) in dorsal (A) and ventral views (B); C, D, left elytron from segment 7 of the holotype RSIO35217 in dorsal view; head and anterior segments of paratype RSIO35219 in dorsal (E) view and ventral (F) view; anterior (G) view of pharynx of paratype RSIO35290; segments of paratype RSIO35219 in dorsal (H) view; ventral (I) view of female ventral papillae on segments 12–16 of holotype RSIO35217; ventral (J) view of male ventral papillae on segments 11 and 12 of paratype RSIO35221; posterior view (upper position) and anterior view (lower position) of right parapodia from holotype RSIO35217 segment 6 (K); anterior (L) view of segment 6 on holotype RSIO35217; M, notochaetae of segment 6 on holotype RSIO35217; N, neurochaetae of segment 6 on holotype RSIO35217. Scale bars: A, B = 5mm, C, E, F, H–L = 0.5 mm, D, M = 100 μm, G = 0.1 mm, N = 30 μm. Type locality: Tiancheng vent field, SWIR . Type material: Holytype ( RSIO35217 ): female, 25 segments, 13.97 mm in length, 6.95 mm in width, Tiancheng vent field ( 27.95°S , 63.53°E , 2760 m deep), SWIR , Dive87, 23 December 2014 . Paratype 1 ( RSIO35219 ): female, 25 segments, 6.43 mm in length, 4.64 mm in width, Longqi vent field ( 37.78°S , 49.65°E , 2740 m deep), SWIR , Dive100, 3 February 2015 . Paratype 2 ( RSIO35221 ): male, part segments remaining, 5.42 mm in length, 3.48 mm in width, Longqi vent field ( 37.78°S , 49.65°E , 2740 m deep), SWIR , Dive90, 3 January 2015 . Paratype 3 ( RSIO35222 ): female, part segments remaining, 3.18 mm in length, 3.43 mm in width, same collecting data as paratype 2. Paratype 4 ( RSIO35290 ): 4.91 mm in length, 2.55 mm in width, Longqi vent field ( 37.78°S , 49.65°E , 2740 m deep), SWIR , Dive94, 11 January 2015 . Paratype 5 ( RSIO38129 ): female, 7.58 mm in length, 5.01 mm in width, Wocan vent field ( 6.36°N , 69.60°E , 2970 m deep), CR, Dive129, 14 March 2017 . Paratype 6 (NSMTPol_P-920): female, 25 segments, 7.42 mm in length, 4.66 mm in width, Edmond vent field ( 23.88°S , 69.60°E , 3277 m deep), CIR, Dive1451, 15 February 2016 . All paratypes were fixed and stored in 95–100% (v/v) ethanol . Description: Body short, tapering anteriorly and posteriorly ( Fig. 2A, B ). Elytra 11 pairs, subreniform ( Fig. 2C ), iridescent when fresh and pale white in ethanol, attached on prominent elytrophores on segments 2, 4, 5, 7, alternating to 21 ( Fig. 2A ), with micropapillae on posterior and lateral border, which can only be seen under SEM ( Fig. 2D ). Prostomium oval, deeply bilobed ( Fig. 2E ). Anterior lobes subtriangle, with delicate frontal filaments ( Fig. 2E ). Median antenna with short, cylindrical ceratophore inserted into anterior notch; style subulate, with a long, terminal filament ( Fig. 2E ). Palps stout, cylindrical, and tapering with terminal filaments. Eyes lacking ( Fig. 2E, F ). First segment achaetous ventrally fused to prostomium, with two pairs of short, cylindrical tentaculophores; tentacular cirri conical, long, and stout with slender filaments ( Fig. 2E, F ). Segment 2 with biramous parapodia bearing the first pair of elytra ( Fig. 2E ); ventral cirri morphologically similar to tentacular cirri and attached basally to neuropodia, much longer than ventral cirri on following segments ( Fig. 2F ). Mouth ventrally located between segments 1 and 2 ( Fig. 2F ). Pharynx when everted, surrounded by seven pairs of papillae on dorsal and ventral sides, as well as one pair of rounded papillae on lateral sides ( Fig. 2G ). Two pairs of curved jaws without teeth at opening of pharynx ( Fig. 2G ). Biramous parapodia with neuropodium about as long as notopodium ( Fig. 2K, L ). Notopodium with rows of notochaetae ( Fig. 2H, L ). Neuropodium with triangle projecting prechaetal lobe ( Fig. 2L ) and short, rounded postchaetal lobe ( Fig. 2K ). Tapering dorsal cirri with long, cylindrical cirrophores attached on posterior dorsal side of notopodia on non-elytrigerous segments ( Fig. 2H, K ). Rows of notochaetae stout, tapering to pointed tips with serrations in distal part ( Fig. 2L, M ). Neurochaetae very numerous, forming fan-shaped bundle ( Fig. 2K, L ) with two rows of widely-spaced acicular spines to hooked tips on both sides ( Fig. 2N ). Pygidium small, rounded, anal cirri lost during collection ( Fig. 2A, B ). Ten pairs of inconspicuous rounded papillae in segments 11–20 in holotype ( Fig. 2I ), which are difficult to observe on other female paratypes due to their small size. On male, two pairs of long, ventral papillae on segments 11 and 12, which extend to the following three segments ( Fig. 2J ). Etymology: The species is named in honour of the late Marian H. Pettibone, in recognition of her great contribution to polynoid taxonomy. Distribution: Tiancheng vent field and Longqi vent field of SWIR, Edmond vent field of CIR, and Wocan vent field of CR. Remarks: Elytralandventralpapillaeareimportantdiagnostic characteristics within Levensteiniella . The combination of these two features can separate Levensteiniella pettiboneae sp. nov. from most other congeners (e.g. Levensteiniella manusensis Wu and Xu, 2018 and Levensteiniella plicata Hourdez and Desbruyères, 2000 ) except for Levensteiniella kincaidi ( Pettibone 1985a ) , which resemble the new species in elytra-bearing micropapillae in posterior and lateral parts, and two pairs of long, ventral papillae on the male ( Pettibone 1985a , 1989 , 1990 , Hourdez and Desbruyères 2000 , 2003 , Wu and Xu 2018 , Zhang et al. 2018b ). However, the two species differ in the number of small, rounded papillae on the female (10 pairs in Levensteiniella pettiboneae sp. nov. vs. nine pairs in Levensteiniella kincaidi ). Moreover, the number of pharyngeal papillae vary in Levensteiniella kincaidi (13–16, mostly seven pairs), while there is an additional pair of lateral papillae in the new species in addition to the seven pairs on the dorsal and ventral sides ( Pettibone 1985a ).