Lepechinella naces Lörz & Engel sp. nov. Materials Type status: Holotype. Occurrence: catalogNumber: NHMW-CR- 29747; recordedBy: IceDIVA 2; individualCount: 1; sex: female; lifeStage: adult; associatedSequences: http://www.ncbi.nlm.nih.gov/nuccore/OR839896; occurrenceID: 1426EB5B-F7E9-52CC-9106-BF28033300EC; Taxon: scientificName: Lepechinella naces Lörz & Engel; kingdom: Animalia; phylum: Arthropoda; class: Malacostraca; order: Amphipoda; family: Lepechinellidae; genus: Lepechinella; specificEpithet: naces; taxonRank: species; scientificNameAuthorship: Lörz & Engel; nomenclaturalCode: ICZN; Location: higherGeography: Atlantic Ocean; waterBody: North Atlantic Ocean; locality: Marine Protected Area NACES, SO 286 station 46; verbatimDepth: 3677 m; verbatimCoordinates: latitude longitude start to end 51.96, - 38.989583 — 51.95755, - 38.98883; decimalLatitude: 51.96; decimalLongitude: - 38.989583; Identification: identifiedBy: Anne-Nina Lörz; dateIdentified: 2023; Event: samplingProtocol: Epibenthic sledge, dragged; eventDate: 27 / 11 / 2021; Record Level: institutionCode: NHMW; collectionCode: CR; basisOfRecord: Preserved Specimen Type status: Paratype. Occurrence: catalogNumber: NHMW-CR- 29748; recordedBy: IceDIVA 2; individualCount: 1; lifeStage: juvenile; associatedSequences: http://www.ncbi.nlm.nih.gov/nuccore/OR839894; occurrenceID: 4197F382-6B13-5917-A6A3-5ABC36EFB81C; Taxon: scientificName: Lepechinella naces Lörz & Engel; kingdom: Animalia; phylum: Arthropoda; class: Malacostraca; order: Amphipoda; family: Lepechinellidae; genus: Lepechinella; specificEpithet: naces; taxonRank: species; scientificNameAuthorship: Lörz & Engel; nomenclaturalCode: ICZN; Location: higherGeography: Atlantic Ocean; waterBody: North Atlantic Ocean; locality: Marine Protected Area NACES, SO 286 station 46; verbatimDepth: 3677 m; verbatimCoordinates: latitude longitude start to end 51.96, - 38.989583 — 51.95755, - 38.98883; decimalLatitude: 51.96; decimalLongitude: - 38.989583; Identification: identifiedBy: Anne-Nina Lörz; dateIdentified: 2023; Event: samplingProtocol: Epibenthic sledge, dragged; eventDate: 27 / 11 / 2021; Record Level: institutionCode: NHMW; collectionCode: CR; basisOfRecord: Preserved Specimen Type status: Other material. Occurrence: catalogNumber: NHMW-CR- 29749; recordedBy: IceDIVA 2; individualCount: 1; lifeStage: juvenile; associatedSequences: http://www.ncbi.nlm.nih.gov/nuccore/OR839895; occurrenceID: 664E1AC9-94D1-5F23-A5F6-052733033BAF; Taxon: scientificName: Lepechinella naces Lörz & Engel; kingdom: Animalia; phylum: Arthropoda; class: Malacostraca; order: Amphipoda; family: Lepechinellidae; genus: Lepechinella; specificEpithet: naces; taxonRank: species; scientificNameAuthorship: Lörz & Engel; nomenclaturalCode: ICZN; Location: higherGeography: Atlantic Ocean; waterBody: North Atlantic Ocean; locality: Marine Protected Area NACES, SO 286 station 46; verbatimDepth: 3677 m; verbatimCoordinates: latitude longitude start to end 51.96, - 38.989583 — 51.95755, - 38.98883; decimalLatitude: 51.96; decimalLongitude: - 38.989583; Identification: identifiedBy: Anne-Nina Lörz; dateIdentified: 2023; Event: samplingProtocol: Epibenthic sledge, dragged; eventDate: 27 / 11 / 2021; Record Level: institutionCode: NHMW; collectionCode: CR; basisOfRecord: Preserved Specimen Description Holotype, NHMW-CR- 29747, DZMB 10099, adult female, 7.3 mm, GenBank number OR 839896. Figs 9, 10, 11, 12. Body setose. Head with rostrum slightly curved, 20 % of length of first peduncle art of A 1; first cephalic tooth long, slender, longer than rostrum; second cephalic tooth acute. A 1, almost reaching length of A 2, shorter than length of body; first article 50 % length of second art, bundle of setae at distal end; third art half the length of first art; flagellum 25 art. A 2, art 3, 4 and 5 with setae, art 5 very slender, longer than art 1–4 combined, with fourth art 60 % length of fifth art; flagellum 18 art. Md with incisor process dentate, lacina mobilis dentate, molar triturative, palp broken off. Mx 1, inner plate with two plumose setae; outer plate with 11 dentate spine teeth; palp second art distally expanded and slightly truncate, distal margin with 10 blunt spine teeth. Mx 2, inner plate with one plumose seta, inner plate narrower and shorter than outer. Mxp, inner plate slender, distally rounded, distal setae; outer plate reaches to the last third of second art of palp, distal part of inner margin with short thick spines apically ending in long spines; palp four art, second art twice the length of third art. Hypopharynx, bilobate, inner lobes well developed extending to half of outer lobe. Prn and Pleon, Prn 1 with two upright teeth. Prn 2–7 and pleon dorsally carinate, each carina terminating in a subacute, posteriorly directed tooth. P 1, coxa not bifid, anterodistally produced, distal margin convex, serrate; basis as long as ischium, merus and carpus combined; basis to propodus setose, palm half the length of posterior margin, dactylus smooth. P 2, coxa marginally setose, tapering distally, anterior margin convex; propodus slender, slightly shorter than basis, palm almost half the length of posterior margin; dactylus small setae. P 3 and P 4, similar in shape, coxae slightly bifid, lobes same length. P 5 and P 6, coxa anterior lobe pointed ventrally, setae on all segments. P 7, coxa rounded, basis to propodus setose. Ep convex posteriorly, each with prominent postero-distal tooth. Urosome Urosomite 1 strongly produced dorsally, urosomite 3 produced extending to more than half of telson length. U 1, peduncle and outer ramus subequal; inner ramus broken; strong spines on peduncle and rami. U 2, outer ramus slightly shorter than inner ramus, subequal in length to peduncle; peduncle and rami with strong spines. U 3, peduncle very short, quarter of length of outer ramus; inner ramus similar length to outer ramus. T, cleft 30 %, lobes each with apical spine, telson length equals length of spine. Variation: The paratype NHMW-CR- 29748, juvenile, 3.2 mm, GenBank number OR 839894 (Fig. 13), morphologically differing from the adult (Figs 9, 10, 11, 12) in the absence of teeth on pereonite 1, weakly-developed carinae on the pereonites and pleonites. Morphological characters are known to vary between age and stages of growth amongst lepechinellid amphipods (Barnard 1973, Thurston 1980, Lörz et al. 2020). The non-type specimen NHMW-CR- 29749, juvenile, 3 mm, collected at the same station as the holotype and paratype, was heavily damaged, but a barcode analysis (GenBank number OR 839895) confirmed 100 % similarity to the holotype. Diagnosis Lepechinella naces Lörz & Engel, sp. nov. is characterised by a setose body, antenna subequal in length, shorter than body, two dorsal teeth on pereonite 1, coxa 1 tapering non-bifid, coxa 7 being rounded and the telson being cleft 30 %. Etymology The specific epithet naces is a noun in apposition, referring to the high seas North Atlantic Current and Evlanov Sea Basin (NACES), a marine protected area (MPA), which covers nearly 600,000 km 2. Taxon discussion Lepechinella naces Lörz & Engel, sp. nov. is morphologically closest to Lepechinella grimi Thurston, 1980 (Thurston 1980), Lepechinella occlo Barnard, 1973 (Barnard 1973), Lepechinella pangola J. L. Barnard, 1962 (Barnard 1962) and Lepechinella victoriae Johansen & Vader, 2015 (Johansen and Vader 2015); these five species bear two distinct extensions on pereonite 1. Table 4 lists differential characters. The closest hits, when blasting the COI sequences of L. naces sp. nov. in BOLD and GenBank, were a Lepechinella specimen not identified to species level, collected in the Kuril Kamchatka Trench (Jażdżewska and Mamos 2019) with 6 % difference and L. grimi from the North Atlantic (Lörz et al. 2020) with 15 % difference. A further species of Lepechinella, which we identified as Lepechinella sp. (NHMW-CR- 29750, GenBank number OR 839893) was collected at the same station as L. naces sp. nov. This specimen morphologically resembles L. skarphedini, which has not been genetically sequenced to date. It differed from L. naces sp. nov. by comparison of the COI segment by more than 20 %. Notes Methods The IceDIVA 2 expedition, initiated and coordinated by the department German Centre for Marine Biodiversity (DZMB), Senckenberg, took place in November and December 2021 via RV Sonne (Brix et al. 2022) in the North Atlantic. Material collected from the Marine Protected Area NACES SO 286 Station 46 by an epibenthic sledge (Brenke 2005) was sorted on board and in the laboratories of the DZMB Hamburg using a Leica 12.5 stereoscope following the protocol described by Riehl et al. (2014 b) with preservation ensuring an undisturbed cooling chain. All lepechinellid specimens sampled are stored at the Crustacea Division, Zoology Department, Natural History Museum Vienna, Austria. Amphipod length was measured from the tip of the rostrum to the end of the telson. The appendages of the left side of the holotype were dissected and temporarily mounted on a slide in glycerine for illustration. Terminology of setae and spines follows Garm and Watling (2013). Pencil drawings were made under a stereoscope Leica MDG 33 and microscope Leitz Diaplan Type 020-437.035 via a camera lucida and digitally inked via the free software Vectr, Pixlr. Photographs of the specimens were made via a Keyence 6000 microscope. The molecular methods follow the protocol of Schwentner and Lörz (2020) for the cytochrome c oxidase subunit 1 (COI), the primers LCO 1490 - JJ / HCO 2198 - JJ were unchanged from Astrin and Stüben (2008). All specimens have a GenBank reference number for their barcode region of the COI.

Published as part of (SOSA), Senckenberg Ocean Species Alliance, Brandt, Angelika, Chen, Chong, Engel, Laura, Esquete, Patricia, Horton, Tammy, Jażdżewska, Anna M., Johannsen, Nele, Kaiser, Stefanie, Kihara, Terue C., Knauber, Henry, Kniesz, Katharina, Landschoff, Jannes, Lörz, Anne-Nina, Machado, Fabrizio M., Martínez-Muñoz, Carlos A., Riehl, Torben, Serpell-Stevens, Amanda, Sigwart, Julia D., Tandberg, Anne Helene S., Tato, Ramiro, Tsuda, Miwako, Vončina, Katarzyna, Watanabe, Hiromi K., Wenz, Christian & Williams, Jason D., 2024, Ocean Species Discoveries 1 – 12 — A primer for accelerating marine invertebrate taxonomy, pp. e 128431 in Biodiversity Data Journal 12 on page e128431, DOI: 10.3897/BDJ.12.e128431