Neanthes goodayi, Drennan & Wiklund & Rabone & Georgieva & Dahlgren & Glover, 2021

Drennan, Regan, Wiklund, Helena, Rabone, Muriel, Georgieva, Magdalena N., Dahlgren, Thomas G. & Glover, Adrian G., 2021, Neanthes goodayi sp. nov. (Annelida, Nereididae), a remarkable new annelid species living inside deep-sea polymetallic nodules, European Journal of Taxonomy 760 (1), pp. 160-185: 166-181

publication ID

https://doi.org/10.5852/ejt.2021.760.1447

publication LSID

lsid:zoobank.org:pub:F96F56AC-158A-400C-A096-ABF06D8C21C0

DOI

http://doi.org/10.5281/zenodo.5167177

persistent identifier

http://treatment.plazi.org/id/C5CDA152-0C73-46BB-955F-9BD5F02BE0F6

taxon LSID

lsid:zoobank.org:act:C5CDA152-0C73-46BB-955F-9BD5F02BE0F6

treatment provided by

Felipe

scientific name

Neanthes goodayi
status

sp. nov.

Neanthes goodayi   sp. nov.

urn:lsid:zoobank.org:act:C5CDA152-0C73-46BB-955F-9BD5F02BE0F6

Figs 2–6 View Fig View Fig View Fig View Fig View Fig , 8 View Fig

Diagnosis

Anterior eye pair very large, distinct, posterior eyes minute. Posterio-dorsal tentacular cirri reaching chaetigers 8–12. Two pigmented spots on dorsum of apodous segment. Palpostyles and palpophores rounded, spherical to ovoid. Paragnaths in pharangeal areas: I = 1–2, II = 9–12, III = 6, IV = 12–16, V = 0, VI = 1–4, VII-VIII = 12–19; area VI–I–VI pattern λ-shaped on oral ring. Chaetigers 1–2 uniramous, remaining chaetigers biramous. Parapodial lobes conical, becoming narrower in posterior chaetigers. Neuracicular postchaetal lobe longer than or equal to neuraciular ligule on anterior chaetigers, shorter on medial chaetigers, papilliform or absent on posterior chaetigers. Dorsal cirri exceed length of ligules on anterior chaetigers, as long as or slightly shorter than ligules on medial chaetigers, becoming longer and exceeding ligules towards posterior end; on largest specimens, dorsal cirri exceed ligules on all chaetigers. Notochatae with homogomph spinigers throughout, supraciular nerurochaetae with homogomph spinigers and heterogomph falcigers throughout, subacicular neurochaetae with homogomph spinigers, homogomph falcigers and heterogomph falcigers throughout.

Etymology

Named in honor of Andy Gooday, member of the science party of both ABYSSLINE cruises. This etymology is part of the ABYSSLINE naming convention where all new taxon names are based on a randomised list of both crew and scientists of the two research cruises in order to recognise the team effort involved in this extensive sampling program ( Wiklund et al. 2019).

Material examined

Holotype PACIFIC OCEAN • Eastern Central Pacific, Clarion Clipperton Fracture Zone ; 12.53717° N, 116.60417° W; depth 4425 m; 20 Feb. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke epibenthic sled, collected from epi-net; specimen guid:21b3d59f-5ec4-40da-9d65-4177e7674f63, field ID: NHM_739, DNA voucher barcode: 0109493268, GenBank COI gene: MZ407918 View Materials ; NHMUK ANEA 2020.260. GoogleMaps  

Paratypes PACIFIC OCEAN – Eastern Central Pacific , Clarion Clipperton Fracture Zone   1 spec.; 13.75833° N, 116.69852° W; depth 4080 m; 11 Oct. 2013; A.G. Glover, H. Wiklund, T.G. Dahlgren and M.N. Georgieva leg.; Brenke epibenthic sled, collected from epi-net; specimen guid: 2d448c5f-bf70-4ed1-a541-9b505ec46434, field ID: NHM_127, DNA voucher barcode: 0109492959, GenBank 16S gene: MZ408645 View Materials ; NHMUK ANEA 2020.33 GoogleMaps   1 spec.; 13.93482° N, 116.55018° W; depth 4082 m; 14 Oct. 2013; same collectors and collection method as for preceding; specimen guid: f5f08fc7-49b4-446f-9f04-fbbca84f7886, field ID: NHM_171, DNA voucher barcode: 0109492952, GenBank 18S gene: MZ408643 View Materials , 16S gene: MZ408646 View Materials , COI gene: MZ407911 View Materials ; NHMUK ANEA 2020.34 GoogleMaps   1 spec.; 13.81167° N, 116.71° W; depth 4076 m; 16 Oct. 2013; same collectors as for preceding; USNEL box corer, collected from 0–2 cm fraction; specimen guid: fb66da6c-f627-487f-a386-3454541ad33a, field ID: NHM_238, DNA voucher barcode: 0109493276, GenBank 16S gene: MZ408648 View Materials , COI gene: MZ407913 View Materials ; NHMUK ANEA 2020.36 GoogleMaps   1 spec.; 12.41628° N, 116.71485° W; depth 4127 m; 16 Feb. 2015; A.G. Glover, H. Wiklund, T.G. Dahlgren and M. Brasier leg.; USNEL box corer, collected from nodule; specimen guid: e1461d7d-c6c8-46fc-b951-f5ee88550a5b, field ID: NHM_512, DNA voucher barcode: 0109493273, GenBank 16S gene: MZ408651 View Materials ; NHMUK ANEA 2020.1 GoogleMaps   1 spec.; 12.53717° N, 116.60417° W; depth 4425 m; 20 Feb. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from epi net; specimen guid: 0d2be1b6-4348-46a2-a1a7-b214562c7b18; field ID: NHM_790, DNA voucher barcode: 0109493261, GenBank 16S gene: MZ408660 View Materials ; NHMUK ANEA 2020.7 GoogleMaps   1 spec.; 12.25733° N, 117.30216° W; depth 4302 m; 1 Mar. 2015; same collectors and collection method as for preceding; specimen guid: bb93253e-2d66-4592-b569-cfa5976fed33, field ID: NHM_1254, DNA voucher barcode: 0109493252, GenBank 16S gene: MZ408667 View Materials ; NHMUK ANEA 2020.17 GoogleMaps   1 spec.; 12.59688° N, 116.49357° W; depth 4258 m; 9 Mar. 2015; same collectors as for preceding; USNEL box corer, collected from nodule; specimen guid: 333370c7-eb36-429c-96ed-fce5658f2ad2, field ID: NHM_1624, DNA voucher barcode: 0109493249, GenBank 16S gene: MZ408670 View Materials ; NHMUK ANEA 2020.20 GoogleMaps   1 spec.; 12.17383° N, 117.19283° W; depth 4045 m; 11 Mar. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from epi-net; specimen guid: 6d7f58fc-a657-47f4-9261-7517228de6a1, field ID: NHM_1783, DNA voucher barcode: 0109493246, GenBank 16S gene: MZ408673 View Materials , COI gene: MZ407927 View Materials ; NHMUK ANEA 2020.23 GoogleMaps   1 spec.; 12.02738° N, 117.3252° W; depth 4139 m; 17 Mar. 2015; same collectors as for preceding; USNEL box corer, collected from nodule; specimen guid: 8abc43ad-193d-4e35-b548-6d2d0b7777f8, field ID: NHM_2069, DNA voucher barcode: 0109493237, GenBank 16S gene: MZ408681 View Materials ; NHMUK ANEA 2020.31 GoogleMaps   .

Other material

PACIFIC OCEAN – Eastern Central Pacific , Clarion Clipperton Fracture Zone   1 spec.; 13.93482° N, 116.55018° W; depth 4082 m; 14 Oct. 2013; A.G. Glover, H. Wiklund, T.G. Dahlgren and M.N. Georgieva leg.; Brenke epibenthic sled, collected from epi-net; specimen guid: 022c1d2a-8b2a-479f-8ed2-20ff4e9610dd, field ID: NHM_173, DNA voucher barcode: 0109493277, GenBank 18S gene: MZ408644 View Materials , 16S gene: MZ408647 View Materials , COI gene: MZ407912 View Materials ; NHMUK ANEA 2020.35 GoogleMaps   1 spec.; 13.81167° N, 116.71° W; depth 4076 m; 16 Oct. 2013; same collectors as for preceding; USNEL box corer, collected from 0–2 cm fraction; specimen guid: 57002bc8-fa3a-4a55-b823-0af978cd2fcd, field ID: NHM_239, DNA voucher barcode: 0109493275, GenBank 16S gene: MZ408649 View Materials , COI gene: MZ407914 View Materials ; NHMUK ANEA 2020.37 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 4a8718c5-d675-4044-9d2b-613f1d8d5fda, field ID: NHM_240, DNA voucher barcode: 0109493274, GenBank 16S gene: MZ408650 View Materials , COI gene: MZ407915 View Materials ; NHMUK ANEA 2020.38 GoogleMaps   1 spec.; 12.38624° N, 116.54867° W; depth 4202 m; 17 Feb. 2015; A.G. Glover, H. Wiklund, T.G. Dahlgren and M. Brasier leg.; Brenke epibenthic sled, collected from epi-net; specimen guid: f61f9136-a39a-4696-8fdc-68aee0af5101, field ID: NHM_614, DNA voucher barcode: 0109493272, GenBank 16S gene: MZ408652 View Materials , COI gene: MZ407916 View Materials ; NHMUK ANEA 2020.2 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 1033aa6b-4093-41fc-af75-9ad090dd4c56, field ID: NHM_644, DNA voucher barcode: 0109493271, GenBank 16S gene: MZ408653 View Materials , COI gene: MZ407917 View Materials ; NHMUK ANEA 2020.257 GoogleMaps   1 spec.; 12.53717° N, 116.60417° W; depth 4425 m; 20 Feb. 2015; same collectors and collection method as for preceding; specimen guid: 9a97230a-4b78-4823-88a5-d02d9c874db9; field ID: NHM_678, DNA voucher barcode: 0109493270, GenBank 16S gene: MZ408654 View Materials ; NHMUK ANEA 2020.258 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 954c9c61-3e45-45a4-8522-7aadd1c86c60; field ID: NHM_692, DNA voucher barcode: 0109493269, GenBank 16S gene: MZ408655 View Materials ; NHMUK ANEA 2020.259 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 76f62614-0cae-4177-8312-e231f5107f8c; field ID: NHM_743, DNA voucher barcode: 0109492976, GenBank 16S gene: MZ408656 View Materials ; NHMUK ANEA 2020.261 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 3951d751-f1ba-44ae-8368-261047c07b12; field ID: NHM_755, DNA voucher barcode: 0109493257, GenBank COI gene: MZ407919 View Materials ; NHMUK ANEA 2020.3 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 67a9133b-c57b-49c6-b6e4-124eb1315eac; field ID: NHM_757, DNA voucher barcode: 0109493258, GenBank 16S gene: MZ408657 View Materials ; NHMUK ANEA 2020.4 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: b13dc262-c631-44dc-927e-6a04c3608bda; field ID: NHM_766, DNA voucher barcode: 0109493259, GenBank 16S gene: MZ408658 View Materials ; NHMUK ANEA 2020.5 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: d9e557c5-3ffd-4a39-9eed-5ecead5e735f; field ID: NHM_783A, DNA voucher barcode: 0109493260, GenBank 16S gene: MZ408659 View Materials ; NHMUK ANEA 2020.6 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 792a4c9a-9653-4ce1-8683-ca2556c1999a8; field ID: NHM_793, DNA voucher barcode: 0109493262, GenBank COI gene: MZ407920 View Materials ; NHMUK ANEA 2020.8 GoogleMaps   1 spec.; 12.57903° N, 116.68697° W; depth 4237 m; 22 Feb. 2015; same collectors as for preceding; USNEL box corer, collected from 0–2 cm fraction; specimen guid: a933dd63-64d1-4e45-95ad-7d68282dd892; field ID: NHM_865, DNA voucher barcode: 0109493263, GenBank COI gene: MZ407921 View Materials ; NHMUK ANEA 2020.9 GoogleMaps   1 spec.; 12.57133° N, 116.6105° W; depth 4198 m; 23 Feb. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from epi-net; specimen guid: 3e7262c7-fd75-4a53-9d6c-9d01955d1bef; field ID: NHM_950, DNA voucher barcode: 0109493264, GenBank 16S gene: MZ408661 View Materials , COI gene: MZ407922 View Materials ; NHMUK ANEA 2020.10 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 06c15319-2b89-4899-b2e5-1fcd8e4a9413; field ID: NHM_971, DNA voucher barcode: 0109493265, GenBank COI gene: MZ407923 View Materials ; NHMUK ANEA 2020.11 GoogleMaps   1 spec.; 12.13367° N, 117.292° W; depth 4122 m; 24 Feb. 2015; same collectors and collection method as for preceding; specimen guid: 165a459f-8b81-4e97-8e82-cdcd013e1ed1; field ID: NHM_1011, DNA voucher barcode: 0109493266, GenBank 16S gene: MZ408662 View Materials , COI gene: MZ407924 View Materials ; NHMUK ANEA 2020.12 GoogleMaps   1 spec.; 12.1155° N, 117.1645° W; depth 4100 m; 26 Feb. 2015; same collectors and collection method as for preceding; specimen guid: a343e242-410a-4817-98c6-7125db7d03e7; field ID: NHM_1079, DNA voucher barcode: 0109493267, GenBank 16S gene: MZ408663 View Materials ; NHMUK ANEA 2020.13 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 7ead0546-d0bd-4381-83af-89f58d8f8f4c; field ID: NHM_1167A, DNA voucher barcode: 0109492975, GenBank 16S gene: MZ408664 View Materials ; NHMUK ANEA 2020.14 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 6b51d602-83f1-4bb4-b71a-e85cdbcbe8dc; field ID: NHM_1171, DNA voucher barcode: 0109493254, GenBank 16S gene: MZ408665 View Materials , COI gene: MZ407925 View Materials ; NHMUK ANEA 2020.15 GoogleMaps   1 spec.; 12.00945° N, 117.17812° W; depth 4144 m; 27 Feb. 2015; same collectors as for preceding; USNEL box corer, collected from nodule; specimen guid: 9e903864-55e8-4a1a-b532-c47af39b95f4; field ID: NHM_1194, DNA voucher barcode: 0109493253, GenBank 16S gene: MZ408666 View Materials ; NHMUK ANEA 2020.16 GoogleMaps   1 spec.; 12.45433° N, 116.61283° W; depth 4137 m; 3 Mar. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from epi-net; specimen guid: e5797775-7141-4eb5-bb5e-dbcb29f7b42e; field ID: NHM_1480E, DNA voucher barcode: 0109493251, GenBank 16S gene: MZ408668 View Materials ; NHMUK ANEA 2020.18 GoogleMaps   1 spec.; 12.51317° N, 116.49133° W; depth 4252 m; 5 Mar. 2015; same collectors and collection method as for preceding; specimen guid: 35bae0ad-f00e-442b-a8f5-b1b318bf1015; field ID: NHM_1515, DNA voucher barcode: 0109493250, GenBank 16S gene: MZ408669 View Materials , COI gene: MZ407926 View Materials ; NHMUK ANEA 2020.19 GoogleMaps   1 spec.; 12.59688° N, 116.49357° W; depth 4258 m; 9 Mar. 2015; same collectors as for preceding; USNEL box corer, collected from nodule; specimen guid: 29f1c1bf-5bca-4ed1-a893-edcd45493e04; field ID: NHM_1631A, DNA voucher barcode: 0109493248, GenBank 16S gene: MZ408671 View Materials ; NHMUK ANEA 2020.21 GoogleMaps   1 spec.; 12.17383° N, 117.19283° W; depth 4045 m; 11 Mar. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from epi-net; specimen guid: 83507a57-c168-4b6f-b984-1c69ccbebc27; field ID: NHM_1764, DNA voucher barcode: 0109493247, GenBank 16S gene: MZ408672 View Materials ; NHMUK ANEA 2020.22 GoogleMaps   1 spec.; 12.0999° N, 117.1966° W; depth 4051 m; 12 Mar. 2015; same collectors as for preceding; USNEL box corer, collected from 0–2 cm fraction; specimen guid: f79fb7b6-ed29-4cc3-9f7f-8d4ace75c585; field ID: NHM_1836A, DNA voucher barcode: 0109493245, GenBank 16S gene: MZ408674 View Materials ; NHMUK ANEA 2020.24 GoogleMaps   1 spec.; 12.0415° N, 117.21717° W; depth 4094 m; 13 Mar. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from epi-net; specimen guid: 0508d326-ef73-4f52-bdc6-757b2ab745fe; field ID: NHM_1866, DNA voucher barcode: 0109492983, GenBank 16S gene: MZ408675 View Materials , COI gene: MZ407928 View Materials ; NHMUK ANEA 2020.25 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 922ad1d7-bd75-4588-ba2e-be32cfe432c5; field ID: NHM_1891, DNA voucher barcode: 0109492960, GenBank 16S gene: MZ408676 View Materials ; NHMUK ANEA 2020.26 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: e991eafe-0593-4e08-8967-d77e017eabac; field ID: NHM_1929A, DNA voucher barcode: 0109493233, GenBank 16S gene: MZ408677 View Materials , COI gene: MZ407929 View Materials ; NHMUK ANEA 2020.27 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 62b28de1-a797-4ec0-99cf-e38625b0e01c; field ID: NHM_1929B, DNA voucher barcode: 0109493234, GenBank 16S gene: MZ408678 View Materials ; NHMUK ANEA 2020.28 GoogleMaps   1 spec.; same collection data as for preceding; specimen guid: 25953aef-8a48-48d1-9fc2-b0a86ec7d052; field ID: NHM_1947D, DNA voucher barcode: 0109493235, GenBank 16S gene: MZ408679 View Materials ; NHMUK ANEA 2020.29 GoogleMaps   1 spec.; 12.0505° N, 117.40467° W; depth 4235 m; 16 Mar. 2015; same collectors and collection method as for preceding; specimen guid: d8edb41d-51d6-4fbd-a547-92fa290209d4; field ID: NHM_2014, DNA voucher barcode: 0109493236, GenBank 16S gene: MZ408680 View Materials , COI gene: MZ407930 View Materials ; NHMUK ANEA 2020.30 GoogleMaps   1 spec.; 12.57133° N, 116.6105° W; depth 4198 m; 23 Feb. 2015; same collectors as for preceding; Brenke epibenthic sled, collected from supra-net; specimen guid: 1c30624d-19a0-43f0-92dc-9a315a3e43fc; field ID: NHM_3074, DNA voucher barcode: 0109493238, GenBank 16S gene: MZ408682 View Materials ; NHMUK ANEA 2020.32 GoogleMaps   .

Comparative material examined

Holotype of Neanthes heteroculata (Hartmann-Schröder, 1981)  

ATLANTIC OCEAN Northeastern Atlantic , Bay of Biscay; 46º35.0′ N, 7º45.5′ W; depth 4700 m; 24 Oct. 1967; ZMH P-16464 GoogleMaps   .

Paratypes of Neanthes heteroculata (Hartmann-Schröder, 1981)  

ATLANTIC OCEAN • 2 specs; same collection data as for preceding; ZMH P-16465.  

Description

Holotype (NHM_739) complete, TL = 12 mm, L15 = 4.7 mm, W15 = 0.9 mm, for 47 chaetigers. Body somewhat ‘baseball bat-shaped’, wide, swollen anteriorly but tapering gradually posteriorly ( Fig. 2A–B View Fig ). Live specimen pale, iridescent and semi-translucent, with yellow gut and red blood vessels visible through body wall ( Fig. 2A, C View Fig ); specimen in ethanol opaque, pale beige, with some red vasculature still visible ( Fig. 2B, D View Fig ). Two pigmented spots on either side of dorsum of apodous segment visible in both live specimens and in ethanol, with some pigmentation also visible on dorsum of anterodorsal tentacular cirrophores ( Fig. 2C–D View Fig ).

Prostomium short, rounded trapezoid with shallow dorsal depression extending anteriorly from midpoint to distal margin ( Fig. 2C–D View Fig ); antennae cirriform, medium-sized, barely extending beyond palps. Palps nearly as long as prostomium, with both palpophores and palpostyles short, spherical, with palpostyles half as long as palpophores. Tentacular cirri with short, cylindrical cirrophores; posterior-dorsal pair of tentacular cirri longest, extending to chaetiger 12 ( Fig. 2A–B View Fig ). Two pairs of dark red eyes; anterior pair very large, rounded teardrop-shaped, with large, rounded lenses inserted anterolaterally and with an irislike structure visible in preserved specimen ( Fig. 2C View Fig ); posterior pair of eyes minute, rounded, with small anterolateral lenses. Apodous anterior segment collar-like, slightly longer and narrower than chaetiger 1.

Pharynx not everted. Jaws dark red-brown with 6 lateral teeth; All paragnaths brown, conical, arranged as follows ( Fig. 2E View Fig ): area I: 2, one large cone, one smaller cone distally; area II: 12 in cluster; area III: approx. 6 (area damaged), four cones in row with two smaller cones laterally; area IV: 13 in teardropshaped cluster, with curved line of cones extending from jaws posteriorly, ending in cluster of 7 cones; area V: no paragnaths; area VIa: 1; area VIb: 4, one large and three smaller cones in trapezoid arrangement; areas VII–VIII: 19, eight large cones in a single well-spaced row with 11 smaller cones scattered laterally. Areas VI–V–VI with λ-shaped ridge pattern.

Chaetigers 1 and 2 uniramous, with all subsequent chaetigers biramous.

Dorsal cirri inserted at base of median and dorsal ligule in uniramous and biramous chaetigers, respectively, slightly inflated on uniramous chaetigers ( Fig. 3A View Fig ), more slender from chaetiger 3 onwards ( Fig. 3B–H View Fig ); dorsal cirri extending beyond median ligule on anteriormost chaetigers ( Fig. 3A–B View Fig ), as long as or slightly shorter than median ligules from chaetiger 6 onwards ( Fig. 3C–D View Fig ) and extending beyond median ligules from around chaetiger 29 ( Fig. 3E View Fig ), up to twice as long as median ligules on posterior chaetigers from chaetiger 40 ( Fig. 3G–H View Fig ).

Dorsal ligule conical throughout, slightly shorter than median ligules on anterior chaetigers ( Fig. 3B–C View Fig ), approximately two-thirds the length of median ligules from chaetiger 10 onwards. Dorsal and median ligules reduced in size on posterior chaetigers from chaetiger 40, with dorsal ligule vanishing in posteriormost chaetigers ( Fig. 3H View Fig ). Median ligule slightly inflated on uniramous chaetigers ( Fig. 3A View Fig ), conical on biramous chaetigers, narrower from chaetiger 29 ( Fig. 3E View Fig ), bluntly conical on posteriormost chaetigers ( Fig. 3H View Fig ). Notopodial prechaetal lobe indistinct.

Neuracicular ligule shorter than ventral neuropodial ligule on anterior chaetigers ( Fig. 3A–C View Fig ), becoming equal in length or slightly shorter from chaetiger 10, equal or slightly longer from chaetiger 29 ( Fig. 3E View Fig ). Superior neuropodial lobe indistinct, truncate throughout; inferior lobe short, rounded on anterior and medial chaetigers, gradually shortening, giving neuracicular ligule pointed appearance on posterior chaetigers ( Fig. 3G–H View Fig ). Neuracicular prechaetal lobe indistinct. Neuracicular postchaetal lobe conical, longer than neuracicular lobe on anteriormost chaetigers ( Fig. 3A–B View Fig ), equal in length at chaetiger 6 ( Fig. 3C View Fig ), gradually shortening and becoming more digitiform on subsequent chaetigers to papilliform nub around chaetiger 29 ( Fig. 3F View Fig ), absent in posterior chaetigers from around chaetiger 40.

Ventral neuropodial ligule conical throughout, gradually narrowing on medial ( Fig. 3E View Fig ) and posterior chaetigers ( Fig. 3G–H View Fig ). Ligule sub-equal in length to median ligule in anterior and early medial chaetigers ( Fig. 3A–D View Fig ), becoming shorter in remaining chaetigers from chaetiger 29 ( Fig. 3E View Fig ), to two-thirds as long as ligule from chaetiger 40 ( Fig. 3G View Fig ) and half as long on posteriormost chaetigers ( Fig. 3H View Fig ).

Ventral cirri cirriform ( Fig. 3C–F View Fig ), inserted basally to ventral neuropodial ligule throughout, slightly shorter than ligule on anterior and medial chaetigers, subequal in length on posteriormost chaetigers ( Fig. 3F View Fig ).

Pygidium somewhat pyriform, truncate distally, with two filamentous anal cirri attached ventro-laterally, extending 8 chaetigers in length ( Fig. 2A–B View Fig ).

Caecal glands present, small, white, slightly thickened.

Multiple aciculae per parapodial lobe observed on some chaetigers in holotype: double neuraciculae in chaetigers 2, 3, 6 and 20 ( Fig. 3B–D View Fig ), and triple notoaciculae on chaetiger 6 ( Fig. 3C View Fig ). This feature was not observed in parapodial dissections from paratypes.

Notochaetae all homogomph spinigers with long blades, of similar width towards toothed edge but drastically slendering to an aristate distal end ( Fig. 3I View Fig ); 4 present in anterior chaetigers, 5 in medial chaetigers, 3 in posterior chaetigers and absent from chaetiger 46.

Supracicular neurochaetae with homogomph spinigers and heterogomph falcigers, both types present in all falcigers except final two chaetigers, where supracicular falcigers are absent. Homogomph spinigers similar in appearance to those of notopodia ( Fig. 3J View Fig ), though with blades reducing in length moving ventrally (shortest blades two-thirds as long as longest blade), numbering 4 on first two chaetigers, 3–5 on anterior and medial chaetigers and 2 on posterior chaetigers where fascicles remain. Heterogomph falcigers with knob-like tips ( Fig. 3K View Fig ) and blades roughly half the length of shortest spinigers, numbering 1 on anterior chaetigers, 2 on medial chaetigers and 1 on posterior chaetigers where fascicles remain.

Subacicular neurochaetae with homogomph spinigers and both homogomph and heterogomph falcigers. Homogomph spinigers also similar in appearance to those of notopodia ( Fig. 3L View Fig ) but with blades twothirds as long and numbering 1–2 on all chaetigers. Homogomph falcigers with knob-like tips ( Fig. 3L View Fig ), blades three-quarters the length of spinigers ( Fig. 3L View Fig ), numbering 1–3 on all chaetigers. Heterogomph falcigers similar in appearance to those of supracicular fascicles ( Fig. 3M View Fig ), numbering 3 on first two chaetigers, 4–6 on anterior, 2–4 on medial and 2–3 on posterior chaetigers.

Variations

Largest specimen (paratype NHM_2069) damaged, in two parts, TL = 17 mm, L15 = 6.7 mm, W15 = 1 mm for 55 chaetigers. Smallest specimen (paratype NHM_127) with TL = 1 mm for 10 chaetigers (see Juveniles section below). Pigment spots on dorsum as in holotype, consistent across most specimens both live and preserved ( Fig. 4A–D View Fig ), pigmentation on tentacular cirrophores more variable. Palpophores spherical to ovoid in shape (e.g., Fig. 4B View Fig ). Posterior-dorsal pair of tentacular cirri extending to chaetiger 8–12 in most specimens (max. chaetiger 6 in juveniles). Eyes dark red to purple, anterior pair ranging from circular/ovoid ( Fig. 4B–D View Fig ) to teardrop-shaped concave discs or deeper cups ( Figs 4A View Fig , 5A View Fig ), becoming more crescent-shaped with decreasing size ( Fig. 5B–D View Fig ); posterior pair mostly circular ( Fig. 4A–B View Fig ), but occasionally oblong ( Fig. 4A View Fig ) or seeming to fuse with anterior pair ( Fig. 6A–B View Fig ), or with one missing ( Fig. 4D View Fig ). Posterior eye pair often less distinct in smaller specimens ( Fig. 5A–B View Fig ), becoming tiny spots ( Fig. 5A View Fig ) or patchy and irregularly shaped ( Fig. 5B View Fig ), completely absent in smallest specimens ( Fig. 5C–D View Fig ), with trace of lens not obvious. Apodous anterior segment longer and narrower than chaetiger 1, as in holotype, to similar in length and width as chaetiger 1 ( Fig. 4A–D View Fig ).

Jaws with 6–7 lateral teeth; paragnaths in pharangeal areas in non-holotype specimens: I = 1–2, II = 9–12, III = 6, IV = 12–16, V = 0, VI = 2–3, VII–VIII = 12–17 (8 large cones in a row as in holotype, varying number of smaller cones scattered laterally). Only one specimen (epitoke male, paratype NHM_1783) with pharynx everted ( Fig. 6B View Fig ).

In largest specimen, dorsal cirrus exceeds median ligule on all chaetigers, neuracicular ligule remains slightly longer than ventral ligule on median and posterior chaetigers, prechaetal lobe remains as

visible papilliform process on posterior chaetigers, ventral ligule subequal to ventral ligule from medial chaetigers onwards and ventral cirri longer than ventral ligule on posteriormost chaetigers.

Numbers of chaetae greater for most fascicles in largest specimen: notochaetae 6 homogomph spinigers on anterior and medial chaetigers, 4 in posterior chaetigers, 1 in posteriormost chaetigers; supracicular neurochaetae with 5–7 homogomph spinigers on first two chaetigers, 2–4 on anterior and medial chaetigers, 1 on posterior chaetigers, heterogomph falcigers 3 on first two chaetigers, 4–6 on anterior chaetigers, 0–3 on medial chaetigers and 1 on posterior chaetigers; subacicular neurochaetae with 2–4 homogomph spinigers most chaetigers, 1 on posteriormost chaetigers, homogmph falcigers 3–5 on anterior chaetigers, 1–2 on medial chaetigers, 1 on posterior chaetigers, heterogomph falcigers 6–9 on anterior chaetigers, 1–3 on medial and posterior chaetigers.

Description of epitoke paratype

One epitokous specimen observed (paratype NHM_1783) ( Fig. 6A View Fig ). Specimen moderately damaged, posteriorly incomplete, TL= 10 mm, L15 = 4 mm, for 37 chaetigers (chaetiger 15 damaged, width at chaetiger 14 excluding parapodia 0.8 mm). Body divided into two regions: pre-natatory with 14 chaetigers and natatory with at least 23 chaetigers; post-natatory region unknown. Eyes not notably modified ( Fig. 6A–B View Fig ); anterior pair with iris-like structure as in holotype, posterior pair somewhat fused to anterior pair.

Pre-natatory chaetigers with modified dorsal and ventral cirri on chaeigers 1–7; notably thickened, but with distalmost tip remaining fine and cirriform ( Fig. 6C View Fig ). Chaetal types in pre-natatory chaetigers as in holotype.

Natatory chaetigers with distinctly enlarged, elongate modified parapodia ( Fig. 6D View Fig ). Noto- and neuropodia elongated basally, with ligules and lobes not significantly larger than on non-modified parapodia. Neuracicular ligule with lamellar structure distally. Both dorsal and ventral cirri notably elongate, with a pair of conical lobes emerging from the upper and lower base of each cirrus, not present on anterior chaetigers; dorsal cirri slightly papillated ( Fig. 6D–E View Fig ). Both notopodial and neuropodial fascicles dense, up to 40 chaetae per fascicle, and with only a single chaetal type: long, simple sesquigomph spinigers with ensiform (knife-shaped) blades ( Fig. 6F View Fig ). No gametes observed, though the presence of slightly papillated dorsal cirri on natatory chaetigers suggests that this specimen is a male ( Read 2007).

Juveniles

Several small, possibly juvenile specimens were observed; paratypes NHM_127, NHM_171, NHM_1254, TL = 1.0– 2.5 mm, L15 = max. 2.2 mm, W15 = max. 0.2 mm, 10–18 chaetigers ( Fig. 5A–D View Fig ). Posterio-dorsal tentacular cirri extending to chaetiger 6. Eyes poorly developed in these specimens, with anterior eye pair observed only as faintly pigmented crescents ( Fig. 5B–D View Fig ), lenses not obvious; posterior eye pair not visible in smallest specimens ( Fig. 5C–D View Fig ). The identity of these specimens was confirmed with genetic data. Due to their size and the delicate nature of specimens, pharyngeal and parapodial dissections were not conducted to preserve specimen integrity.

Genetic data

All 43 individuals were sequenced for 16S and COI. The gene 16S was successfully sequenced in all but six specimens. COI sequencing was less successful; however, each specimen had coverage of at least one of the two genes. All specimens formed a single clade with low intraspecific divergence. Several specimens were also sequenced for 18S in order to assess deeper taxonomic relationships. This species was genetically distinct from all other species included in our phylogenetic analyses, and forms the basal branch of a clade including Neanthes fucata (Savigny, 1822)   and five species of Perinereis Kinberg, 1865   ( Fig. 7 View Fig ).

Remarks

This species is most consistent with the genus Neanthes Kinberg, 1865   , most recently defined by Ibrahim et al. (2019). Previous analyses based on morphological parsimony suggested that neither of the three most species-rich nereidid genera, Neanthes   , Nereis   and Perinereis   , can be considered monophyletic, with many generic characters displaying high homoplasy ( Bakken & Wilson 2005). Molecular phylogenetic analyses carried out in this study supported the polyphyly of Neanthes   , as sequences of species currently regarded as Neanthes   , both from the ABYSSLINE material and from GenBank, rarely grouped together and were evenly distributed throughout a tree that included 11 other nereidid genera.

Neanthes goodayi   sp. nov. can be differentiated from the majority of its congeners by the notably large anterior pair of eyes. Only N. heteroculata (Hartmann-Schröder, 1981)   , described from abyssal (4700 m) waters off the Bay of Biscay in the northeastern Atlantic, appears to possess comparably large anterior and minute posterior pairs of eyes. Neanthes heteroculata   and N. goodayi   sp. nov. also display similarities with regard to several other characters, such as the appearance of the prostomium, antennae and tentacular cirri, in addition to the types of chaetae present and their appearance and arrangement. Based on an examination of the type material of N. heteroculata   , N. goodayi   sp. nov. differs in having distinctly rounded, spherical to ovoid palpophores (e.g., Fig. 4B View Fig ), with palpophores in N. heteroculata   found to be narrower, bluntly conical in shape. Furthermore, the dorsal cirri are relatively short in N. heteroculata   , not exceeding the length of the notopodial ligules, whereas they exceed the length of the notopodial ligules in at least anterior and posterior chaetigers in N. goodayi   sp. nov.

Notably, N. heteroculata   is one of a handful of species of Neanthes   reported from the deep sea. Of the 84 currently valid species of Neanthes ( Read & Fauchald 2020b)   only 13 have been reported from depths greater than 200 m ( Khlebovich 1996; Shimabukuro et al. 2017; Hsueh 2019). Of these, N. goodayi   sp. nov. also resembles N. papillosa ( Day, 1963)   , described from deep (2745 m) waters off Cape Town, South Africa. Neanthes papillosa   similarly possesses an enlarged anterior pair of eyes relative to the posterior pair, in addition to long tentacular cirri, relatively elongate, conical parapodial ligules, and dorsal cirri that exceed the length of the notopodial ligules, becoming longer on posterior chaetigers. The holotype of N. papillosa   is noted to have pale, poorly chitinised paragnaths, thus making them difficult to observe ( Day 1963). However, despite having fewer paragnaths in number across all areas, they appear to be organised in similar arrangements as in N. goodayi   sp. nov., such as a single row of paragnaths on areas VII–VIII (single row of large cones in N. goodayi   sp. nov. with varying numbers of smaller cones laterally). However, N. papillosa   can primarily be differentiated from N. goodayi   sp. nov. in that the anterior pair of eyes does not appear to be as strikingly large as in N. goodayi   sp. nov. or N. heteroculata   ; thus, there is less disparity between the anterior and posterior eye pairs in size. Additionally, N. papillosa   can be further distinguished in that it does not bear homogomph falcigers and that parapodial lobes of midbody and posterior chaetigers bear numerous club-shaped papillae; however, it is worth considering that some characters of N. papillosa   may be reproductive modifications, as the holotype is described from a single epikotous female specimen.

Neanthes goodayi   sp. nov. also bears similarities to N. vitiazi Khlebovich, 1996   from abyssal waters (3342–4160 m) of southern Japan, primarily in terms of broadly similar paragnath distributions, bearing homogomph falcigers and in having a large anterior pair of eyes, which are illustrated as rings without strong pigment. Neanthes vitiazi   differs in that it has long, digitate median ligules positioned at right angles to the notoacicula on midbody and posterior chaetigers. Neanthes vitiazi   is also described as having brown pigmentation on parapodial appendages and dense spot-like pigmentation on the apodous anterior segment; N. goodayi   sp. nov. similarly bears two pigmented spots on the dorso-lateral anterior margin of this segment; however, these are relatively small, whereas the spots in Neanthes vitiazi   span much of the length of the segment and are placed dorsally, behind the eyes.

The geographically most proximal deep-water species, N. mexicana Fauchald, 1972   , described from abyssal waters off Baja California, and N. sandiegensis Fauchald, 1977   from the San Diego Trough (728–855 m), can also be differentiated from N. goodayi   sp. nov. Neanthes mexicana   was originally described from a single damaged specimen, re-examined and revised by de León-González & Solís- Weiss (2000) with the addition of several nereidids collected from abyssal waters off California USA agreeing with the type specimen. Neanthes mexicana   is described as bearing a single pair of very large red eyes, with diffuse pigment spots posterior to the eyes noted to perhaps represent the posterior eye pair ( Fauchald 1972). In ABYSSLINE specimens, the appearance of the posterior eye pair was variable, ranging from discrete dark spots to more faint, irregular shapes, occasionally with one or both eyes absent all together, particularly in smaller specimens. The eye morphology of N. mexicana   therefore falls within the variation observed in the ABYSSLINE samples. Neanthes mexicana   and N. goodayi   sp. nov. also share similarities in terms of parapodial morphology, with all parapodial ligules broadly conical to somewhat triangular in shape (see de León-González & Solís-Weiss 2000: fig. 3). However, N. mexicana   differs from N. goodayi   sp. nov. in terms of palp morphology (long, digitate palpostyles), the arrangement and number of paragnaths (4 cones in areas II and IV versus 12 cones in both areas in N. goodayi   sp. nov.,) and in lacking homogomph falcigers.

Neanthes sandiegensis   is only known from a single damaged specimen. However, it differs from N. goodayi   sp. nov. primarily in terms of parapodial morphology, bearing large, foliose dorsal notopodial ligules with medially inserted, long, flattened digitate dorsal cirri, long digitate prechaetal notopodial lobes and notably elongate ventral neuropodial ligules. Neanthes sandiegensis   also differs in terms of the distribution and number of paragnaths on most pharyngeal areas (I = 0, II =2, VI= 6–8, VII–VIII = 35 in N. sandiegensis   , I = 2, II = 12, VI = 1–4, VIII–VIII = 19 in the holotype of N. goodayi   sp. nov.).

While none of the morphologically most similar or geographically proximal congeners had genetic data available for comparison, morphological differences existed in each case. Neanthes goodayi   sp. nov. can be differentiated from other deep-water Neanthes spp.   primarily in terms of eye morphology: N. articulata Knox, 1960   , N. donggungensis Hsueh, 2019   , N. kerguelensis (McIntosh, 1885)   and N. suluensis Kirkegaard, 1995   bear two relatively small, subequal eye pairs, whereas N. bioculata (Hartmann-Schröder, 1975)   bears a single pair of small eyes; N. abyssorum Hartman 1967   , N. kermadeca (Kirkegaard, 1995)   , N. shinkai Shimabukuro et al., 2017   and N. typhla (Monro, 1930)   are recorded as lacking eyes altogether and can be further differentiated from N. goodayi   sp. nov. in terms of paragnath distribution, among other characters (see Shimabukuro et al. 2017 for comparative morphological table of most deep water Neanthes spp.   ).

Ecology

Neanthes goodayi   sp. nov. was found at depths ranging from 4000 to 4400 m living in crevices of polymetallic nodules ( Fig. 8A–B View Fig ), burrowing in xenophyophore foraminifera growing on nodules ( Fig. 8C–E View Fig ) or in mud balls on nodule surfaces ( Fig. 8F–H View Fig ). As in other nereidids, the strong eversible jaws, together with large eyes, indicate an active and predatory behaviour. While we were able to observe live, moving specimens kept at cold temperatures even after recovery from 4000 m water depth, behaviours such as predation were not observed. Polymetallic nodules are thought to contain a diverse meiofaunal community of nematodes, copepods and other small crustaceans; thus, it is possible that N. goodayi   sp. nov. is a ‘sit and wait’ predator that is able to remain inside the nodules and detect prey passing overhead through extremely small variations in light (from local bioluminescence, detected by the large eyes) or other physio-chemical cues.

Distribution

Eastern Clarion Clipperton Fracture Zone, Central Eastern Pacific.

NHMUK

Natural History Museum, London