Lumbrinerides cf. laubieri (NHM_0020)

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

Lumbrinerides cf. laubieri (NHM_0020)

Figs 9A-G , 10A-I , 11A-K

Material examined.

NHM_0020, NHM ANEA 2022.801, coll. 9 Oct. 2013, AB01, UK-1, EBS, 13.8372, -116.55843, 4336 m, https://data.nhm.ac.uk/object/cfc84885-578e-4b87-a14f-e8fc1cf2a5a0; NHM_0028, NHM ANEA 2022.802, coll. 9 Oct. 2013, AB01, UK-1, EBS, 13.8372, -116.55843, 4336 m, https://data.nhm.ac.uk/object/0adcf12b-4027-4893-98a2-588d60e352a3; NHM_1146, NHM ANEA 2022.803, coll. 26 Feb. 2015, AB02, OMS, EBS, 12.1155, -117.1645, 4100 m, https://data.nhm.ac.uk/object/4849b790-53a1-45f8-a7e0-3f60062642cd; NHM_2245, NHM ANEA 2022.805, coll. 1 Mar. 2015, AB02, OMS, EBS, 12.25733, -117.30217, 4302 m, https://data.nhm.ac.uk/object/024a6d28-6775-4d01-823b-3b0a03fcd727; NHM_3492, NHM ANEA 2022.804, coll. 1 Mar. 2020, RC01, OMS, Box core, 14.03696, -116.50802, 4138 m, https://data.nhm.ac.uk/object/e6b00cf4-5c01-453d-a1ff-5c7dc0783960; NHM_4738_ECDS1, NHM ANEA 2022.808, coll. 28 Feb. 2020, RC01, UK-1, Box core, 13.98698, -116.47664, 4059 m, https://data.nhm.ac.uk/object/c78086ef-af8a-4b1c-b9db-e61df25585f4; NHM_4738_ECDS3, NHM ANEA 2022.807, coll. 28 Feb. 2020, RC01, UK-1, Box core, 13.98698, -116.47664, 4059 m, https://data.nhm.ac.uk/object/7d7e9048-38fa-4503-b256-6e6ac3c23687; NHM_4738_ECDS5, NHM ANEA 2022.806, coll. 28 Feb. 2020, RC01, UK-1, Box core, 13.98698, -116.47664, 4059 m, https://data.nhm.ac.uk/object/2806a25b-e00e-4845-9b6a-10ca95b3fd6a; NHM_4743_ECDS1, NHM ANEA 2022.809, coll. 4 Mar. 2020, RC01, UK-1, Box core, 13.99732, -116.52824, 4102 m, https://data.nhm.ac.uk/object/d42c9eb3-2052-4e90-9e00-61e20291d674; NHM_8777_HW01, NHM ANEA 2022.811, coll. 12 Nov. 2020, DG05a, NORI-D, Box core, 10.3781, -117.14689, 4300 m, https://data.nhm.ac.uk/object/18c5a2d0-2bd6-48e2-bd02-9fe7c03ae7a4; NHM_8810, NHM ANEA 2022.815, coll. 23 Nov. 2020, DG05a, NORI-D, Box core, 10.3554, -117.22087, 4289 m, https://data.nhm.ac.uk/object/75d2356a-cfd2-4ea8-b6d4-7d69ee27cb1c; NHM_8855, NHM ANEA 2022.816, coll. 30 Oct. 2020, DG05a, NORI-D, Box core, 10.92904, -116.26351, 4262 m, https://data.nhm.ac.uk/object/2250d689-4b91-4998-8776-05db9d437c89; NHM_8874, NHM ANEA 2022.817, coll. 2 Nov. 2020, DG05a, NORI-D, Box core, 10.9714, -116.16494, 4240 m, https://data.nhm.ac.uk/object/4d437d57-72b5-4f7a-84b7-87b13b6c422d; NHM_8898_LN01, NHM ANEA 2022.812, coll. 2 Nov. 2020, DG05a, NORI-D, Box core, 10.97448, -116.35427, 4260 m, https://data.nhm.ac.uk/object/af52e52a-9c50-432e-a88c-1f03cb6f981c; NHM_8898_LN02, NHM ANEA 2022.813, coll. 2 Nov. 2020, DG05a, NORI-D, Box core, 10.97448, -116.35427, 4260 m, https://data.nhm.ac.uk/object/123e1f28-a76e-4929-9c58-7ffd80db14a2; NHM_8898_LN03, NHM ANEA 2022.814, coll. 2 Nov. 2020, DG05a, NORI-D, Box core, 10.97448, -116.35427, 4260 m, https://data.nhm.ac.uk/object/2c462f72-683e-4fb3-bef9-8a8fe10b98f3; NHM_8798_HW02, NHM ANEA 2022.810, coll. 8 Nov. 2020, DG05a, NORI-D, Box core, 10.32571, -117.17753, 4300 m, https://data.nhm.ac.uk/object/568f9a43-2c36-49be-8829-55edb69ba271.

Comparative material examined.

Fig. 12A-I . Lumbrinerides laubieri Miura, 1980; holotype MNHN.1278. NE Atlantic, Gulf of Gascogne , Biogas IV, DS61, coll. 24 Feb 1974, 24.02.1974, 47.5686111, -9.6355556, 2 250 m.

Description.

All specimens posteriorly incomplete, including voucher specimens NHM_0020, NHM_ 4378_ECDS5, NHM_1146, NHM_2245 and NHM_3492. Body slender, narrow, and cylindrical measuring up to 3.1 mm in length for 11 chaetigers and width of 0.2-0.25 mm. Live specimens iridescent and slightly translucent, with visible spotted pattern along sides of prostomium; preserved specimens milky white in ethanol (Fig. 9A ). Jaws typically visible through body (Fig. 9E ).

Prostomium significantly longer than wide (Figs 9A , 10A , 11A ), narrow, conical, bluntly pointed, with small papilla at the tip; with spotted pigmentation across length of prostomium. Peristomium with two rings (Fig. 10B, C ), the first with a V-shaped notch on the ventral side.

Maxillary apparatus with four pairs of maxillae (Fig. 9D, F ). All maxillae with attachment lamellae. Carriers as long as MI and joined to their entire base (Fig. 9D ). Carriers with wide anterior base and coloured dark brown to black. MI without internal accessory teeth. Attachment lamellae along lateral edge of MI, thin and weakly sclerotised. MII shorter than MI with three rounded teeth. MIII as edentate plate, pigmented dark brown. MIV as edentate plate, appear elongated and slightly pointed, approximately triangular (Fig. 9F ). Mandibles fused for entire length with three pigmented bands (Fig. 9G ).

Parapodia reduced to. Chaetigers 1 and 2 distinctly longer than wide, with reduced parapodia, no lobes developed, situated laterally (Fig. 10D, E, F ). Chaetiger 3 ca. as wide as long, with reduced parapodia shifted dorsolaterally, no lobes developed (Fig. 10D, G ). Chaetiger 4 ca. as wide as long with small tongue-like postchaetal lobe (Figs 10D, H , 11C ), shifted dorsolaterally. From chaetiger 5, chaetigers ca. as wide as long, shifted dorsally, with small tongue-like postchaetal lobes developed (Figs 10D, I , 11B, D ). Pre-chaetal lobes always smaller than postchaetal lobes.

Chaetae of two types observed in all chaetigers: 1. simple bidentate hooded hooks with two teeth at ~ 45° from each other, with subdistal spur, 1-3 hooks per parapodium, usually two present (Figs 9B , 11I, J ) and two winged limbate capillaries (Fig. 9C ), usually two per parapodium; in chaetiger 1-4 capillaries broadly limbate (with elbow) (Fig. 11E-H ), from chaetiger 5 narrowly limbate (Figs 9C , 11K ). Aciculae yellow. Remainder of body and pygidium unknown.

Genetic data.

In our phylogenetic analysis, Lumbrinerides cf. laubieri (NHM_0020) forms a well-supported monophyletic clade with another, as yet unnamed Lumbrinerides species (Fig. 3 ).

There are many identical or near-identical COI matches to unnamed specimens on GenBank that were previously collected at the CCZ ( Janssen et al. 2015, 2019). There are no genetic data from the type or non-type specimens of Lumbrinerides laubieri .

Remarks.

This small species was the most abundant lumbrinerid in our CCZ samples, represented by 211 specimens. Morphologically, this species is similar to Lumbrinerides laubieri Miura, 1980, described from the Gulf of Gascony, France at lower bathyal depths of 1894-2775 m. Outside its type locality, L. laubieri has been reported in the North Aegean Sea at 156-300 m ( Simboura and Zenetos 2005). Following the initial examination of CCZ specimens, these matched L. laubieri in several instances: small body size; greatly elongated prostomium; reduced parapodia in first three chaetigers; maxillae I without accessory teeth; mandibles with "concentric striations" consistent with the coloured bands seen on CCZ specimens (Fig. 9G ); attachment lamellae supporting the maxillary apparatus present (Fig. 9D ); two types of chaetae present, limbate capillary chaetae and simple bidentate hooded hooks (Fig. 9B, C ).

The holotype MNHN.1278 of L. laubieri was re-examined as part of this study (Fig. 12A-I ). The holotype is a small, very slender specimen, consisting of three fragments: the anterior fragment with 15 chaetigers being 4.5 mm long and 0.25 mm wide (Fig. 12A, B ), a body fragment with six chaetigers, and a small 2-chaetiger long body fragment. The jaws were partially damaged during a previous investigation. Chaetae (particularly the limbate type) were often broken off.

In a recent revision of Lumbrinerides from Japanese water, Miura (2017) suggested new characters of taxonomic importance in this genus. Therefore, during the examination of type material particular attention has been paid to the following characters: the chaetiger on which the first hooks arise, the number of hooks per parapodium and the number of anterior reduced parapodia. No obvious differences were observed (Table 2 ), other than the presence of up to three hooks in some parapodia in CCZ specimens, while at most two were observed in the holotype of L. laubieri . However, other more subtle differences were observed that are usually not considered in the discussion of the taxonomic characters in Lumbrineridae . These differences refer to relative size of various features, unlikely to be related to size of specimen as all individuals investigated had small and very slender body of similar dimensions. The hooded hooks in CCZ specimens are very small and slender, with dentition only clearly observable under oil (x100 magnification), while the hooks in L. laubieri are much chunkier and easy to observe even under lower magnification ( × 40) (Fig. 12H, I ). Similarly, the development of broad limbation (elbow) on capillaries of anterior chaetigers is much more distinct in L. laubieri (Fig. 12C, G ) compared to CCZ specimens (Fig. 12E ). Characters discussed by Miura (2017) or in this study are summarised in Table 2 .

Lastly, a bathymetric distributional pattern should be also taken into consideration as L. laubieri has been found in shallower depth (1894-2775 m) in the Atlantic, compared to CCZ specimens (~ 5000 m) in the Pacific. Depth is considered to be a greater barrier to gene flow compared to with horizontal distances (e.g., Atlantic vs. Pacific) ( Taylor and Roterman 2017). Unfortunately, molecular data from L. laubieri is not available for comparison. Thus, it is currently difficult to establish the new species based on CCZ specimens, and these are cautiously ascribed to Lumbrinerides cf. laubieri Miura, 1980.

Two more Lumbrinerides species have a conical, greatly elongated prostomium: Lumbrinerides carpinei (Ramos, 1976) described from Mediterranean Sea (off Monaco, at depths of 200-600 m) and Lumbrinerides yoshioi Miura, 2017 from shallow depths off Hokkaido, Japan. However, they have the following differences from CCZ specimens. Lumbrinerides carpinei has one long apodous segment rather than two peristomial rings, lacks visible mandibles and has accessory tooth on MI ( Miura 1980). Lumbrinerides yoshioi differs in having 9-10 reduced anterior parapodia (as opposed to 3 in CCZ specimens) and in MI having two weakly projected accessory teeth (as opposed to no accessory teeth in CCZ specimens).

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 9. Lumbrinerides cf. laubieri A anterior fragment of specimen NHM _ 1146 in dorsal view B simple bidentate hooded hook on chaetiger 3, specimen NHM _ 1146 C winged limbate capillary chaetae on chaetiger 5 specimen, NHM _ 1146 D maxillary apparatus, specimen NHM _ 1146 E everted jaws in specimen NHM _ 3492 F maxillary apparatus of specimen NHM _ 1146 (MIII = maxilla 3, MIV = maxilla 4) G maxillary apparatus of specimen NHM _ 2245 (md. = mandibles). Scale bars: 50 µm (C); 10 µm (B); 100 µm (D, E, F, G). Abbreviations: ca. = carriers, MI = maxilla 1, MII = maxilla 2, al = attachment lamellae.

Figure 10. Lumbrinerides cf. laubieri (specimen NHM _ 4378 _ ECDS 5) A posteriorly incomplete preserved specimen B anterior end with margins between prostomium and 2 - rigned peristomium C anterior end with margins between prostomium, peristomium and chaetiger 1 D chaetigers 2 - 7 marked by arrows, showing the shift of parapodia from lateral to dorsal position E chaetiger 1 F chaetiger 2 G chaetiger 3 H chaetiger 4 with postchaetal lobe I chaetigers 5 - 6 with postchaetal lobes. Scale bars: 250 µm (A, C, D); 100 µm (B); 25 µm (F, G, H); 50 µm (I).

Figure 11. Lumbrinerides cf. laubieri (specimen NHM _ 0020) A posteriorly incomplete preserved specimen B parapodia of chaetiger 4 and dorsally shifted parapodia of chaetiger 5, both with developed postchaetal lobes C detail of pre- and postchaetal lobes of chaetiger 4 D detail of pre- and postchaetal lobes of chaetiger 5 E chaetae of chaetiger 1, with limbate chaetae showing broad limbation (elbow) F chaetae of chaetiger 2 G chaetae of chaetiger 3 H chaetae of chaetiger 4 I simple hooded hook of chaetiger 4 J simple hooded hook of chaetiger 7 K narrowly limbate capillary from chaetiger 5. Scale bars: 250 µm (A); 50 µm (B); 25 µm (C-K).

Figure 12. Lumbrinerides laubieri, holotype MNHN. 1278 A, B preserved specimen in dorsal view C chaetiger 1 D, E chaetiger 4 with postchaetal lobe F postchaetal lobe from chaetiger 10 G broadly limbate chaetae from chaetiger 1 H, I hooded hooks, with inserts showing the detail of bidentate dentition. Scale bars: 1 mm (A, B); 250 µm (C, F G, H, I); 500 µm (D, E).