Lumbrineris sp. NHM_1741

Neal, Lenka, Abrahams, Emily, Wiklund, Helena, Rabone, Muriel, Bribiesca-Contreras, Guadalupe, Stewart, Eva C. D., Dahlgren, Thomas G. & Glover, Adrian G., 2023, Taxonomy, phylogeny, and biodiversity of Lumbrineridae (Annelida, Polychaeta) from the Central Pacific Clarion-Clipperton Zone, ZooKeys 1172, pp. 61-100 : 61

Lumbrineris sp. NHM_1741

Fig. 13A-G

Material examined.

NHM_0125, coll. 11 Oct. 2013, AB01, UK-1, EBS, 13.75833, -116.69852, 4080 m, https://data.nhm.ac.uk/object/3c704b88-d8ae-42cb-aeae-73e7a20a70b7; NHM_0129, coll. 11 Oct. 2013, AB01, UK-1, EBS, 13.75833, -116.69852, 4080 m, https://data.nhm.ac.uk/object/067a1dee-adcb-4c7f-8445-b68176b5c41b; NHM_8899, NHM ANEA 2022.851, coll. 2 Nov. 2020, DG05a, NORI-D, Box core, 10.97448, -116.35427, 4260 m, https://data.nhm.ac.uk/object/462dea9c-52cb-48bb-8e60-43c5f4f5d472; NHM_0229, NHM ANEA 2022.818, coll. 15 Oct. 2013, AB01, UK-1, ROV, 13.96467, -116.54988, 4072 m, https://data.nhm.ac.uk/object/9474abbe-8d3a-4db8-9897-ff206977918f; NHM_0972, NHM ANEA 2022.820, coll. 23 Feb. 2015, AB02, UK-1, EBS, 12.57133, -116.6105, 4198 m, https://data.nhm.ac.uk/object/c570a340-f2e6-405d-b0b8-f335c9056fbd; NHM_1308, NHM ANEA 2022.830, coll. 1 Mar. 2015, AB02, OMS, EBS, 12.25733, -117.30217, 4302 m, https://data.nhm.ac.uk/object/2d378a92-05c4-417a-9cc7-1c392baf0db7; NHM_1741, NHM ANEA 2022.819, coll. 11 Mar. 2015, AB02, OMS, EBS, 12.17383, -117.19283, 4045 m, https://data.nhm.ac.uk/object/86010404-eae6-4c58-943a-1761c81fa201; NHM_1896, NHM ANEA 2022.829, coll. 13 Mar. 2015, AB02, OMS, EBS, 12.0415, -117.21717, 4094 m, https://data.nhm.ac.uk/object/acf2aa8f-3ca5-4728-ab42-782576ab57fd; NHM_2318, NHM ANEA 2022.821, coll. 26 Feb. 2015, AB02, OMS, EBS, 12.1155, -117.1645, 4100 m, https://data.nhm.ac.uk/object/83e28d46-6d21-4fe6-a9a6-2c7360cfbaa4; NHM_2374, NHM ANEA 2022.822, coll. 20 Feb. 2015, AB02, UK-1, EBS, 12.51317, -116.60417, 4425 m, https://data.nhm.ac.uk/object/f1cda422-c3a0-47cb-b63a-40a1d92232d7; NHM_3133, NHM ANEA 2022.828, coll. 17 Feb. 2015, AB02, UK-1, EBS, 12.38624, -116.54867, 4202 m, https://data.nhm.ac.uk/object/0f6f9455-d82a-4afa-9a12-5f6771e66763; NHM_3591, NHM ANEA 2022.824, coll. 3 Mar. 2020, RC01, OMS, Box core, 14.06995, -116.57628, 4120 m, https://data.nhm.ac.uk/object/23c92bc4-3099-45b9-bc63-455e094fd5c7; NHM_4237, NHM ANEA 2022.823, coll. 11 Mar. 2020, RC01, UK-1, Box core, 12.37909, -116.55767, 4196 m, https://data.nhm.ac.uk/object/be32a0a9-56ef-41fc-ae65-cf939128372b; NHM_4738_ECDS2, NHM ANEA 2022.825, coll. 28 Feb. 2020, RC01, UK-1, Box core, 13.98698, -116.47664, 4059 m, https://data.nhm.ac.uk/object/cd4b907b-383e-4a71-8ebb-573a8745a8bc; NHM_7057_HW01, NHM ANEA 2022.827, coll. 13 May 2021, DG05d, NORI-D, Box core, 10.38235, -117.12702, 4309 m, https://data.nhm.ac.uk/object/50895550-0014-46d9-b0ba-76b9e392281b; NHM_7249_HW01, NHM ANEA 2022.831, coll. 14 May 2021, DG05d, NORI-D, Box core, 10.37727, -117.15581, 4302 m, https://data.nhm.ac.uk/object/73e121b5-97fb-4d6e-905f-4387236b9cf6; NHM_8796_HW01, NHM ANEA 2022.826, coll. 6 Nov. 2020, DG05a, NORI-D, Box core, 10.32294, -117.18734, 4282 m, https://data.nhm.ac.uk/object/30460632-eb9b-4655-81c2-c1ce3b2cebdd.

Description.

Species represented by several posteriorly incomplete specimens. Voucher specimen NHM_1741 (Fig. 13A ), 10 mm long 0.8 mm wide for ~ 40 chaetigers long anterior fragment. Live specimens with distinctive spotted pattern across the width of the chaetigers and on prostomium on the dorsum (Fig. 13A ). When preserved in ethanol the body is a milky white, retaining iridescent sheen. Body thick in anterior, tapering towards posterior.

Prostomium conical (e.g., specimen NHM_0229) to slightly longer and distally pointed (e.g., specimen NHM_1741) (Fig. 13A ), as long or slightly longer than wide; some specimens with prostomium appearing distally truncated (e.g., specimen NHM_2374).

Maxillary apparatus with five pairs of maxillae pigmented pale to dark brown (Fig. 13B ). All maxillae with attachment lamellae Carriers ca. equal length as MI and joined entirely to base of MI. MI appears paler with a dark edge; forceps-like, without inner accessory teeth and strongly falcate. MI longer than MII. Connecting plates between MI and MII slightly visible. MII with four pointed teeth, with ligaments (Fig. 13B insert). MIII unidentate, arcuate (Fig. 13B insert), with darkened area on anterior lateral edge. MIV oval shaped and pigmented light brown. MV circular in shape and positioned laterally to MIV. Mandibles fused ~ ½ their length.

Parapodia small and uniramous, increasing in size after the first two chaetigers. Postchaetal lobe longer than pre-chaetal lobe, postchaetal lobe elongated and digitiform, particularly in posterior chaetigers (Fig. 13C ). Chaetigers narrow and ring-like until chaetiger 22 where they become longer and more bead-like.

Chaetae characterised by limbate capillaries, simple multidentate hooded hooks and compound multidentate hooded hooks (Fig. 13D-G ). Approximately four limbate chaetae in anterior chaetigers (Fig. 13D ), increasing in length towards posterior end but decreasing in number. Transition from compound to simple hooks variable (likely size-dependent), with compound multidentate hooded hooks present from chaetiger 1 to 6-15; two or three compound multidentate hooded hooks present. Compound hooks with short blades, with ~ 10 small teeth in lateral view (Fig. 13E ) or fewer (Fig. 13F ). Simple multidentate hooded hooks appear from chaetigers 8-16, simple hooks only from chaetiger 10 onwards, ~ 2 per parapodia. Simple hooks with ~ 12 small teeth in lateral view (Fig. 13G ). Aciculae yellow. Posterior end and pygidium unknown.

Genetic data.

This species falls within a low-support clade containing Lumbrineris and Helmutneris species in our analysis (Fig. 3 ). There were COI matches on GenBank to four unclassified annelid specimens also collected at the CCZ, GenBank accession numbers KJ736511.1-KJ736514.1 ( Janssen et al. 2015).

Remarks.

The maxillary apparatus and chaetae composition of this species are indicative of the genus Lumbrineris de Blainville, 1828. The strongly arcuate cutting edges of MIII (Fig. 13B ) are a typical character of Lumbrineris cingulata Ehlers, 1897 ( Orensanz 1990; Oug pers. comm., 2023), known from the shelf depths of Magellanic biogeographic province ( Carrera-Parra 2006b). Several species reported by Carrera-Parra (2006b), all known from shallow depths, also share this character. CCZ specimens have four teeth on MII, a character further shared by only three known species with MIII with arcuate edge: L. cingulata , L. inhacea Hartman, 1974 and L. mustaquimi Carrera-Parra, 2006b. Some distinguishing characters, mostly based on observation of the hooks, have been summarised in Table 3 . CCZ specimens likely belong to a new species that cannot be currently fully formalised; therefore, we assign CCZ specimens to morphospecies Lumbrineris sp. NHM_1741.

Distribution.

Central Pacific Ocean, Eastern CCZ, found in ‘UK-1’, ‘OMS’ and ‘NORI-D’ exploratory areas (Fig. 1 ).

Figures

Figure 1. Map of CCZ of exploration areas and Areas of Particular Environmental Interest (APEI) with targeted areas (highlighted in colours; see legend) where samples for this study were collected.

Figure 3. Majority rule consensus tree from the Bayesian analyses using combined datasets for COI, 16 S and 18 S genes, with 36 terminal taxa of which Tainokia logachevae (Oenonidae), Eunice rubra (Eunicidae) and Nothria conchylega (Onuphidae) were used as outgroup. Posterior probability values are marked on nodes.

Figure 13. Lumbrineris sp. NHM _ 1741, specimen NHM _ 1741, unless stated otherwise A live anterior fragment of specimen in lateral view B maxillary apparatus specimen NHM _ 0229; insert - the detail of teeth on MII and detail of MIII, showing arcuate edge C 22 nd parapodium with well-developed postchaetal lobe D limbate capillaries on chaetigers 4 and 5 E compound hooks on chaetiger 5, insert - detail of the hook dentition F compound hook from chaetiger 10 G simple multidentate hooded hook chaetiger 12, inset - detail of the hook dentition. Scale bars: 100 µm (C, D); 25 µm (E, F, G).