Diversity and distribution of the deep-sea Atlantic Acanthocope (Crustacea, Isopoda, Munnopsidae), with description of two new species

Author’s Accepted Manuscript Diversity and distribution of the deep-sea Atlantic Acanthocope (Crustacea, Isopoda, Munnopsidae), with description of two new species Marina V. Malyutina, Inmaculada Frutos, Angelika Brandt www.elsevier.com/locate/dsr2

PII: DOI: Reference:

S0967-0645(17)30028-0 https://doi.org/10.1016/j.dsr2.2017.11.003 DSRII4345

To appear in: Deep-Sea Research Part II Received date: 1 February 2017 Revised date: 26 October 2017 Accepted date: 1 November 2017 Cite this article as: Marina V. Malyutina, Inmaculada Frutos and Angelika Brandt, Diversity and distribution of the deep-sea Atlantic Acanthocope (Crustacea, Isopoda, Munnopsidae), with description of two new species, DeepSea Research Part II, https://doi.org/10.1016/j.dsr2.2017.11.003 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Diversity and distribution of the deep-sea Atlantic Acanthocope (Crustacea, Isopoda, Munnopsidae), with description of two new species Marina V. Malyutina1,2*, Inmaculada Frutos3,6, Angelika Brandt3,4,5 1

A.V. Zhirmunsky Institute of Marine Biology, National Scientific Center of Marine Biology,

Far Eastern Branch, Russian Academy of Sciences, Palchevskogo 17, 690041 2

Far East Federal University, Oktiabrskaya Str, 29, 690600,Vladivostok, Russia

3

Zoological Museum Hamburg, Center of Natural History, University of Hamburg, Martin-

Luther-King-Platz 3, D-20146 Hamburg, Germany 4

Senckenberg Research Institute and Museum, Senckenberganlage 25, D-60325 Frankfurt,

Germany (present address) 5

Goethe-University of Frankfurt, FB 15, Institute for Ecology, Evolution and Diversity, Max-

von-Laue-Str. 13, 60439 Frankfurt am Main, Germany 6

Dpto. Ciencias de la Vida, EU-US Marine Biodiversity Group, Universidad de Alcalá, 28871

Alcalá de Henares, Spain *

Corresponding author. [email protected]

Abstract The present paper provides data of the world-wide distribution, abundance and diversity of the rare deep-sea munnopsid genus, Acanthocope Beddard, 1885 and presents an identification key to the 18 known species of Acanthocope. Two new species, Acanthocope puertoricana sp. nov. from the tropical abyssal area near the Puerto Rico Trench and Acanthocope galaica sp. nov. from the Galicia Bank, Northeastern Atlantic are described. Additionally, Acanthocope annulatus Menzies, 1962 and Acanthocope eleganta Malyutina and Brandt, 2004 have been collected in the Puerto Rico Trench area, whereas Acanthocope galatheae Wolff, 1962 were collected along a latitudinal transect crossing the tropical abyssal North Atlantic during the Vema-TRANSIT expedition. A. puertoricana is most similar to A. carinata Chardy, 1972 from the Northwestern Atlantic and differs from the latter by: a more slender body; a broader head; a more slender and shorter lateral projections of the pleotelson; the presence of ventral spines on natasome; and a longer uropod. A. galaica sp. nov. is most similar to A. spinicauda Beddard, 1885 and differs from the latter by having a more elongate pleotelson with almost straight lateral margins between lateral spines, whereas the margins

are more convex in A. spinicauda. Pereopods 5 and 6 of A. galaica have broader carpi than in A. spinicauda.

Keywords Atlantic Ocean, deep sea, macrobenthos, distribution, abundance, Isopoda, Munnopsidae, Acanthocope, new species, key

1. Introduction At the end of the 19th century the genus Acanthocope Beddard, 1885 was erected for two species, Acanthocope acutispina Beddard, 1885 and Acanthocope spinicauda Beddard, 1885. Since then, 16 species of the genus have been described and only one of them, A. eleganta Malyutina and Brandt, 2004 was described in the current century. The subfamily Acanthocopinae Wolff, 1962 is monotypical and most species of Acanthocope are rare, known only from the type locality, and are based on a single or few, mainly female specimens. The only species, known to be abundant and widely distributed, is A. galatheae Wolff, 1962. This species was described from the Gulf of Panama, Northeast (NE) Pacific and has subsequently been found in many samples of recent deep-sea Atlantic expeditions, namely from a few abyssal basins from the South (S) Atlantic and the Southern Ocean (SO) (Brandt et al. 2005, 2007; Malyutina and Brandt, 2007; Schmidt et al., 2002) and it was possibly sampled in the Northwest (NW) Pacific (as A. cf. galatheae in Malyutina and Brandt, 2015). Only six species of the genus have been described from the northern hemisphere: three boreal species, A. carinata Chardy, 1972 and A. armata Chardy, 1972 from the N Atlantic, and A. curticauda Birstein, 1970 from the NW Pacific and three species from tropical areas of the northern hemisphere: A. spinosissima Menzies, 1956 from the W Atlantic; A. pentacornis Müller, 1989 from the NW Indian Ocean and A. galatheae from the Gulf of Panama in the E Pacific. Beside these six northern hemisphere species, all other species have been described from southern tropical latitudes to the SO: seven species in the S Atlantic (A. annulatus Menzies, 1962; A. argentinae Menzies, 1962; A. beddardi Malyutina, 1999; A. eleganta Malyutina and Brandt, 2004; A. muelleri Malyutina, 1999; A. spinicauda, A. unicornis Menzies, 1962); two species, Acanthocope orbus Menzies and George, 1972 and A. acutispina in the E Pacific, A. mendeleevi Malyutina, 1998 in the SW Pacific and A. spinicauda is described from the SE Indian Ocean. A. annulatus, described from the SW

Atlantic off Cape Town, was later found near the Antarctic Peninsula (Malyutina and Brandt, 2004). During the recent expedition Vema-TRANSIT along the Vema Fracture Zone, four species of the deep-sea munnopsid genus Acanthocope were sampled. One of these, a new species A. puertoricana sp. nov. from the tropical abyssal area near the Puerto Rico Trench is described. A. galaica sp. nov., collected at bathyal depths of the Galicia Bank (NE Atlantic) during the recent expedition INDEMARES BANGAL 0711 (Inventario y Designación de la red NATURA 2000 Marina en España, Banco de Galicia) is described herein as well. The abundance of these five newly recorded Acanthocope species in the N Atlantic is compared with the previous Acanthocope records from abyssal depth in the S Atlantic, SO and the NW Pacific, where quantitative data were available. An identification key to the currently known 18 species of Acanthocope is provided and a distributional map of the species, updated after Malyutina and Brandt (2004), is present as well.

2. Material and Methods The specimens examined in the present study were collected during two recent expedition carried out in the N Atlantic deep-sea. Samples were taken by means two types of sledges, both equipped with two superimposed nets (0.5 mm mesh size), which allowed the sampling of the fauna from above the sea floor. They also had an opening-closing mechanism for the nets which activates when the sledge contacts the sea floor which avoids accidental catches during its deployment into the water column. Acanthocope specimens were collected during the expedition Vema-TRANSIT between 15 December 2014 and 26 January 2015 on board the RV Sonne in the tropical N Atlantic (Fig. 1, Appendix 1), along a latitudinal transect across the Atlantic in the Vema Fracture Zone and in the Puerto Rico Trench area by means of a camera-epibenthic sledge (CEBS) (Brandt et al., 2013). On board, the material was fixed immediately in -20°C precooled 96% ethanol for 48 hours. Specimens of Acanthocope galaica sp. nov. were collected during INDEMARES BANGAL 0711 expedition on board the RV Miguel Oliver which carried out sampling at the Galicia Bank (NW Iberian Peninsula, NE Atlantic) in July‒August 2011 (Fig. 1, Appendix 1). Samples were taken by means a suprabenthic sledge (Frutos, 2006). The material was fixed on board with a solution of 4% formalin in sea water, and then stored in 70% ethanol. In the laboratory, the material was sorted and identified using an Olympus SZx7 dissecting microscope and a Nikon SMZ 1500, and illustrated with an Olympus SZx7

microscope, equipped with a camera lucida. Terminology and measurements follow Wilson (1989) and Malyutina (2003). Total body length was measured medially from the anterior edge of the head to the posterior tip of the pleotelsonic terminal spine. As spines can be broken in some specimens, we have also provided measurements of the body or its parts in some cases without spines. Length of segments were measured medially or laterally from the anterior margin (without anterior spine if present) to the posterior margin. Spines were measured from the tip to the base along the anterolateral margin. The type material of Acanthocope puertoricana sp. nov. have been deposited in the Zoological Museum of Hamburg University, Germany. The type specimens of Acanthocope galaica sp. nov. were deposited in the Museo Nacional de Ciencias Naturales, Madrid, Spain. Abundance of Acanthocope species (expressed as ind/1000 m2, see table 2) was calculated in relation with the bottom area swept by the sledge during each haul. The article is registered in ZooBank under urn:lsid:zoobank.org:pub:47A0610F-3278-40DEA900-08DAD59829F7 The following abbreviations are used in the text and figures: ZMH = Zoological Museum Hamburg MNCN = Museo Nacional de Ciencias Naturales TL = total length C-EBS = camera-epibenthic sledge UBS = unequally bifid seta

3. Taxonomy ASELLOTA Latreille, 1803 MUNNOPSIDAE Lilljeborg, 1864 Acanthocopinae Wolff, 1962 Acanthocope Beddard, 1885 Acanthocope Beddard, 1885: 922; 1886: 78; Menzies, 1956: 2; 1962: 152; Wolff, 1962: 110; Chardy, 1972: 386; Malyutina, 1998: 343–346; 1999: 288–289; Malyutina and Brandt, 2004: 2. Type species: Acanthocope spinicauda Beddard, 1885, designated by Menzies (1962).

Diagnosis: Body with spines. Natasome completely fused. Antennula short in female and long in male. Mandibular palp either absent or of 1 or 2 articles, if of 3 articles, thin, with last article elongate and straight. Male pleopods 1 and 2 forming high, dome-like operculum; pleopod 1 half or less length of pleopod 2. Uropods cylindrical, elongate, uniramous or with tiny exopod. Extended diagnosis: Body with lateral, dorsal, terminal and often ventral spines. Head without spines, interantennular distance more than half as wide as head, frontal margin straight. Lateral margins of pereonites 1–4 rounded, coxae of pereopod 1 short and rounded, of pereopods 2–4 projected into spines. Natasome completely fused, pereonites 5–7 with anterolateral spines, often with ventral spines. Pleotelson with 2 pairs of lateral spines and 1 terminal spine. Antenna 1 article 1 without spines, flagellum short, with few articles in females and long, multiarticulated in males. Antenna 2 articles 1 and 2 fused without suture; article 2 with distomedial spine, article 3 without squama, with distomedial and distolateral spines; mandibular palp absent or with 1 or 2 articles, if of 3 articles, thin, with last article elongate and straight; maxillipedal palp article 2 largest, with expanded rounded lateral margin, article 3 as broad as article 1, triangular. Pereopods 1–4 similar, slender; pereopods 5–7 with rather narrow crescent-shaped carpi and narrow oval propodi, smaller than carpi; dactyli not tapering distally, with 2–3 long dorsal and 1–2 small ventral setae on oblique distal margin. Male pleopods 1 and 2 forming high, dome-like operculum; pleopod 1 half or less length of pleopod 2; pleopod 2 protopod with ventromedial projection, limiting position of pleopod 1, endopod and exopod inserted basally. Uropods cylindrical, elongate, uniramous or with tiny exopod. For composition of the genus see Table 1 and the key to species of Acanthocope.

Acanthocope puertoricana sp. nov. (Figs 2–9) urn:lsid:zoobank.org:act:9F5D9EE1-D98C-4711-B83E-350DA3E0FE52 Material examined: Holotype: male (6.9 mm TL), ZMH K–46195, Puerto Rico Trench abyssal area, RV Sonne, Vema-TRANSIT cruise, 25 January 2015, C-EBS, station 14–1, 19º1.63’N 67º9.73’W, 4552‒ 4552 m depth, supranet, bottom temperature: 2.25ºC, bottom O2: 261.13 μM, bottom current: 5.25 cm/s. Paratypes: 1 brooding (full marsupium) female (8.7 mm TL), ZMH K–46196; 1 male (7.5 mm TL), ZMH K–46197, dissected; 1 anterior body part of brooding (full marsupium) female, ZMH K–46198. All paratype sampling data as for holotype.

Diagnosis: Body length about 3.0 width. Head length about 0.6 width, broadened posteriorly. Pereonite 1 visibly narrower than head. Natasome with two long ventromedial spines; pereonites 5–7 with broad lobe-like anterolateral projections, with pair of short anterodorsal spines. Pleotelson terminal spine slender, as long as pleotelson; anterolateral spines broad, triangular, posterolateral spines slender, slightly longer than anterolateral ones, slightly curved, directed posteriorly. Male pleopod 2 length >2 pleopod 1 length. Uropod subequal in length to terminal spine of pleotelson, protopod length 2.4 pleotelson posterolateral spine. Description of the holotype: Body (Fig. 2A–C) TL 3.0 pereonite 5 width, (length without terminal spine 2.3 width). Dorsal surface of pereon smooth, pleotelson with weak fine medial keel, all lateral margins of natasome and coxal spines with elongate transparent scale spinules, anterior margin of lateral spines with long seta, terminal spine with spines and long setae around. Head length 0.6 width, broadened posteriorly, with smooth dorsum, lateral margins in dorsal view straight, with acute tubercles and small setae, frontal margin smooth, thickened, interantennular distance 0.4 head width and 2.5 antenna 1 basal width. Pereonite 1 length 0.15 head length, width 0.8 head width; pereonites 1–4 slightly broadening and elongating from 1 to 4, pereonite 4 twice as long as pereonite 1; pereonite 1 without dorsomedial spine, coxae small, rounded. Pereonites 2–4 anteriorly with a dorsomedial straight spine, directed upwards, slightly longer than respective pereonite; lateral margins of pereonites 1–4 rounded, smooth; coxal spine of pereopods 2–4 subequal in length and in shape, about 0.6 of pereonite half width, directed somewhat anteriorly. Natasome TL 3.1 anterior body part length, length without terminal spine 2.1 length of anterior body part. Pereonites 5–7 of the same length, slightly decreasing in width from 5 to 7; anterolateral projections of pereonites 5–7 almost as long as posterolateral margin of pereonites, twice as broad as coxal spines of pereopods 2–4, projections of pereonites 5 and 6 directed slightly anteriorly, those of pereonite 7 perpendicular to body axis. Pereonites 5–7 with pair of short anterodorsal spines each, spines on pereonite 5 situated closer to each other, directed anteromedially, spines on pereonites 6 and 7 similar, with same distance in between, twice as long as that for pereonite 5, directed upwards. Ventral spines of pereonites 5 and 6 slender, as long as lateral projections. Pleotelson length without terminal spine 0.8 width, terminal spine slender, as long as pleotelson. Anterolateral spines broad triangular, posterior margin perpendicular to body axis, posterolateral spines slender, 0.3 as wide as anterolateral

ones, slightly curved, directed posteriorly, pleotelson lateral margin in between spines slightly convex; dorsum with anteromedial spine and weak keel; preanal ventral process small. Antenna 1 (Fig. 4A) length 0.65 body length; article 1 length 1.9 width, with row of lateral spinules, dorsal tubercles and small setae, distal lobe tapering; article 2 visibly longer than distal lobe of article 1, length 1.3 width, widening distally, with one distomedial broom seta; articles 3 and 4 0.7 and 0.5 times as long as article 2 respectively. Flagellum of more than 50 articles, last ten with one aesthetasc and few small simple setae each. Antenna 2 (Fig. 2A, B) broken off after article 4; articles 2 and 3 subequal in size, with short distolateral and longer distomedial spines; article 3 spines slightly longer than article 2 spines; article 4 0.7 times as long and wide as article 3. Mandible (Fig. 4C, D) both incisors with 3 cusps, lacinia mobilis of left mandible slightly shorter than incisor, with 3 narrow distal teeth, spine row with 5 and 6 spines on left and right mandibles respectively, molar process distally with one small seta; condyle length 0.25 mandible body length, palp of 3 articles subequal in size, article 3 comb-like, with one short distal seta. Maxilla 1 (Fig. 5A) mesial endite width 0.6 lateral endite width, lateral endite with 11 robust setae (4 of them serrated) and many fine small setae. Maxilla 2 (Fig. 5B) mesial and lateral endites subequal in length, middle endite shortest; mesial endite with row distal setae, including 7 comb-like setae and one long setulated seta distomedially, middle and lateral endites with 4 distal long setulated setae. Maxilliped (Fig. 5C) basis length 2.4 width, endite with four coupling hooks, distal margin oblique, with 4 fan setae and numerous slender simple setae. Palp article 2 almost as long as wide, slightly narrower than basis, laterally 1.3 times as long as medially; article 3 0.7 times as wide as article 2, length 0.9 article 2 length medially and 0.15 laterally, medial margin straight, with 14 rather long setulated setae; article 4 3.25 as long as article 3 laterally, medial lobe slightly shorter and broader than article 5, both lobe and article 5 with 5 simple distal setae each; lateral margin of basis, articles 1–3 with dense row of fine setae; epipod 3.5 times as long as wide, 0.9 as long as basis, tip rounded distally, lateral margin projected proximally. Pereopods (Figs 6, 7) increasing in size from 1 to 4, pereopod 4 length 1.7 pereopod 1 length, pereopod 5 subequal in length to pereopod 2; basis of pereopod 5 shortest and broadest, basis of pereopod 1 subequal in length to 5. All bases with marginal spinules, few broom setae on dorsal margin and small sparse marginal setae.

Pereopod 1 (Fig. 6A) ratios of lengths of ischium–dactylus to basis: 0.35, 0.2, 1.2, 0.8, 0.3, carpus and propodus with few small marginal simple setae, propodus with tuft of setulated distal setae. Pereopod 2 (Fig. 6B) ratios of lengths of ischium–dactylus to basis: 0.3, 0.15, 1.0, 0.65, 0.7; carpus with 9 ventral robust setae on distal half and 6 simple setae on proximal half; propodus with 6 ventral robust setae, both articles with distodorsal tuft of a few whip setae and 1 broom seta. Pereopod 3 (Fig. 6C) ratios of lengths of ischium–dactylus to basis: 0.3, 0.2, 1.25, 0.9, 0.65, carpus with 13 robust setae on distoventral half, and 3 simple setae proximally, 9 setae dorsally; propodus with 12 robust UBS and 2 simple ventral setae, ventral margin with 6 UB setae and 4 simple setae and 1 dorsomedial broom seta, both articles with distodorsal tuft of a few whip setae and 1 broom seta. Pereopod 4 (Fig. 6D) ratios of lengths of ischium–dactylus to basis: 0.35, 0.2, 1.2, 1.0, 0.65, carpus with 13 robust UBS on ventral distal half, and 3 simple setae proximally, propodus with 12 robust and 2 simple ventral setae and 6 robust and 4 simple dorsal setae and 1 mediodorsal broom seta, both the articles with distodorsal tuft of a few whip setae and one broom seta. Pereopod 5 (Fig. 7A) ratios of lengths of ischium–dactylus to basis: 0.6, 0.25, 1.45, 1.3, 0.6, carpus 3.3 times as long as wide, 2.2 times as wide as basis, propodus 6.8 times as long as wide. Dactylus with 3 long distodorsal setae and 2 short robust setae and 2 fine setae on distoventral tip. Pereopod 7 (Fig. 7B) ratios of lengths of ischium–dactylus to basis: 0.5, 0.2, 1.15, 1.3, 0.55, carpus 5.4 times as long as wide, width 0.6 carpus 5 width, propodus 13.5 times as long as wide. Pleopod 1 (Fig. 8A–D) 1.9 times as long as wide, each side with proximal oblique keel and low keels along medial fusion, with many small spines; distomedial lobes rounded with few setae, distolateral lobes acute, curved inside as claws, twice longer than medial lobes. Pleopod 2 (Fig. 8B, C) length 2.1 pleopod 1 length. Protopod length 1.6 width, lateral margin with small plumose setae, medial margin with low, narrow keel. Ventral spine on proximal third, length 0.1 protopod width, spine and keel with many small spines and tubercles. Pleopod 3 (Fig. 9A) endopod 1.8 times as long as wide, 3 distomedial plumose setae length 0.25 endopod length, exopod 0.3 times as wide and 1.4 times as long as endopod, with

row of fine simple lateral setae, apical article 0.45 times as long as basal one, with 5 plumose setae distally. Pleopod 4 (Fig. 9B) endopod 1.4 as long as wide, with acute distomedial tip, exopod 0.6 as long and 0.15 times as wide as endopod, with tiny distal seta. Pleopod 5 (Fig. 9C) length 1.5 times width. Uropod (Fig. 2D) slightly extending beyond terminal spine of pleotelson, length 1.2 pleotelson length without terminal spine; protopod length 2 width, with scattered simple setae along and few distal setae; endopod length 0.8 protopod length, width 0.7 protopod width, with row of medial small setae, three UB setae, one broom seta and two small setae distally; exopod inconspicuous, tiny, with three distal setae. Female (Figs 2E–F; 3): Pleotelson without dorsal medial keel, mediodorsally slightly granulated. Antenna 1 (Figs 4B) length 0.2 body length, of 8 articles, article 1 length 2 width, with row of lateral spinules, dorsal tubercles and small setae, distal lobe tapering; article 2 as long as article 1 distal lobe, length 1.4 width, widening distally, with one distomedial broom seta; articles 2–8 length 0.25, 0.2, 0.1, 0.4, 0.15, 0.15, 0.15 article 2 length. Antenna 2 (Fig. 3A, B) subequal to body in length, articles 2 and 3 subequal in size, with short distolateral and longer distomedial spines; article 3 spines slightly longer than article 2 spines; article 4 0.7 times as long and wide as article 3. Article 5 length 0.4 TL of body, broadened distally, with three serrate rows of transparent scales along article; article 6 length 0.4 article 5 length, with 6 stout distal setae. Flagellum broken off after 20th article, 1.4 length and 0.25 width of article 6. Pleopod 2 (Fig. 3C) length 1.1 width, ventral spine length 0.5 pereonite 5 ventral spine length, middle keel weakly pronounced, serrated, margins fringed with small plumose setae.

Etymology: The species name is feminine and refers to the type locality of the species.

Remarks: A. puertoricana sp. nov. is most similar to A. carinata Chardy, 1972 from the N Atlantic abyssal plain. The species share the similar general shape of the natasome and pleotelson: pereonites 5–7 have broad lateral projections in contrast to the slender coxal spines of pereonites 2–4; pleotelson with sagittal anterior part, anterolateral projections broad acute posterolateral spines slender curved posteriorly, dorsal keel weak, narrow. A. puertoricana sp. nov. differs from A. carinata in having a more slender body: length 3.0 width in contrast to 2.1 in A. carinata, length without terminal spine 2.3 width (1.7), and

natasome length without terminal spine 1.5 width (1.15). The head is broadened posteriorly and broader than in A. carinata: length 0.6 width A. puertoricana sp. nov. and 0.7 in A. carinata, in which the head is broadened anteriorly. Pereonite 1 of A. puertoricana sp. nov. is visibly narrower than the head, in contrast to A. carinata, where head and pereonite 1 have equal width. The pleotelson of A. puertoricana sp. nov. is more slender than in A. carinata (length 0.8 width vs 0.6), and bears an anterodorsal spine, which is absent in A. carinata. The lateral projections are shorter in A. puertoricana sp. nov.: length 0.15 of pleotelson width (0.2), and posterolateral spines length 0.3 pleotelson length without terminal spine (0.55). The uropod of A. puertoricana sp. nov. is longer than that of A. carinata: protopod length 2.4 pleotelson posterolateral spine in A. puertoricana and 0.8 in A. carinata. Examination of the holotype of A. carinata revealed that this species, like A. puertoricana sp. nov., has ventral spines on pereonites 5 and 6, which were not mentioned in the original description. This character was noted before only for A. mendeleevi Malyutina, 1998, and A. eleganta Malyutina and Brandt, 2004, but as these spines are fragile, they might have been broken off in other species or as with A. carinata were not mentioned. Distribution: Tropical N Atlantic, 4552‒4552 m depth. Known only from the type locality.

Acanthocope galaica sp. nov. (Figs 10–15) urn:lsid:zoobank.org:act:F8ABD18D-D724-4F50-85C0-D21745BA10F6 Material examined: Holotype: male (5.2 mm TL), MNCN 20.04/10607, Galicia Bank, RV Miguel Oliver, INDEMARES BANGAL 0711 cruise, 29 July 2011, suprabenthic sledge, station TS2, 42º57.97’N 12º00.52’W, 1726–1705 m depth, 65–90 cm near-bottom water layer, fine sand bottom, temperature: 5.65ºC, salinity: 35.27. Paratypes. 1 female (5.7 mm TL), MNCN 20.04/10608, Galicia Bank, RV Miguel Oliver, INDEMARES BANGAL 0711 cruise, 7 August 2011, suprabenthic sledge, station TS9, 42º57.55’N 11º59.39’W, 1669‒1674 m depth, 0–65 cm near-bottom water layer, fine sand bottom, temperature: 5.65ºC, salinity: 35.27. 1 male with broken terminal spine (4.4 mm TL), MNCN 20.04/10609; 1 damaged natasome of manca, MNCN 20.04/10610; for both of them data as for MNCN 20.04/10608 paratype. 1 natasome of female, MNCN 20.04/10611, Galicia Bank, RV Miguel Oliver, INDEMARES BANGAL 0711 cruise, 7 August 2011, suprabenthic sledge, station TS9, 42º57.55’N 11º59.39’W, 1669‒1674 m depth, 65–90 cm near-bottom water layer, fine sand bottom, temperature: 5.65ºC, salinity: 35.27.

Diagnosis: Body length about 4.0 body width. Head length about 0.6 width, lateral margins parallel, pereonite 1 visibly narrower than head. Natasome with two long ventromedial spines; pereonites 5–7 with slender anterolateral spines; pleotelson terminal spine slender, shorter than pleotelson (0.9). Anterolateral spines slender, triangular, directed posteriorly, posterolateral spines slender, almost twice as long as anterolateral spines, slightly curved posteriorly. Male pleopod 2 length <2 pleopod 1 length. Description of the holotype: Body (Fig. 10A–D) TL 3.8 pereonite 5 width, (length without terminal spine 2.1 width without lateral spines). Surface of body dorsally and ventrally fine granulated with scattered setae, lateral margins, coxal spines and terminal spine with longer setae. Head length 0.6 width, lateral margins parallel, straight, with tubercles and small setae; frontal margin smooth, thickened; interantennular distance 0.4 head width and 1.8 antenna 1 basal width. Pereonite 1 length 0.2 head length, width 0.85 head width, pereopod 1 coxa small, rounded. Pereonites 1–4 slightly broadening and elongating from 1 to 4, pereonite 4 twice as long as pereonite 1. Pereonites 2–4 anteriorly with dorsomedial slightly curved spine, directed upwards, almost twice as long as respective pereonite; lateral margins of pereonites 1–4 rounded, smooth; coxal spine of pereopods 2–4 slender, subequal in length and in shape, slightly shorter than half width of pereonite. Natasome TL including terminal spine 2.2 anterior body part length, length without spine 1.5 anterior body part length. Pereonites 5–7 of the same length, slightly decreasing in width from 5 to 7; anterolateral projections of pereonites 5–7 slightly longer than posterolateral margin of pereonites, as slender as coxal spines of pereopods 2–4; projections of pereonites 5 directed slightly anteriorly, those of pereonite 6 perpendicular to body axis and of pereonite 7 directed slightly posteriorly. Pereonites 5–7 with pair of short stout dorsal spines anteriorly, spines situated closer to each other, directed anteromedially; pereonite 7 with additional posteromedial small projection. Ventral spines of pereonites 5 and 6 slender, visibly longer than lateral projections. Pleotelson without terminal spine length 0.75 width, terminal spine slender, 0.9 as long as pleotelson. Anterolateral spines slender, triangular, directed backwards, posterolateral spines slender, almost twice as long as anterolateral spines, slightly curved posteriorly, pleotelson lateral margin in between spines almost straight, longer than anterolateral spines and shorter than posterolateral spines; dorsum with anteromedial spine and weak keel; preanal ventral process short, spines in front of uropod insertions 0.4 as long as anal operculum. Antenna 1 (Figs 10B,12A) length 0.65 TL; article 1 length 1.8 width, with rows of lateral and minute spines and dorsal tubercles, distal lobe tapering; article 2 slightly longer

than distal lobe of article 1, length 1.2 width, with distomedial acute projection; articles 3 and 4 length 0.7 and 0.5 article 2 length, flagellum of more than 50 articles. Antenna 2 (Fig. 12A) broken off after article 4; articles 2 and 3 subequal in size, with long distomedial spines; article 3 spine longer than article 2 spine; article 4 0.7 times as long and wide as article 3. Mandible (Fig. 13A, B) both incisors with three cusps, lacinia mobilis of left mandible shorter than incisor, with five narrow distal teeth, spine row with six and seven spines on left and right mandibles respectively. Molar process distally with two small setae, condyle length 0.25 mandible body length. Palp length 0.9 mandible body length, articles 2 and 3 1.35 and 1.1 of article 1 length, article 3 comb-like, with one long distal seta and row of short setae. Maxilla 1 (Fig. 12B) mesial endite width 0.9 lateral endite width, lateral endite with 11 robust setae (4 of them serrated) and many fine small setae. Maxilla 2 (Fig. 12C) mesial and lateral endites subequal in length, middle endite shortest; mesial endite with row distal setae, including seven comb-like setae and one long setulated seta distomedially, middle and lateral endites with 4 distal long setulated setae: two long and two shorter. Maxilliped (Fig. 13C, D) basis 2.7 as long as wide; endite 0.4 as long and 0.55 as wide as basis, with five coupling hooks, distal margin oblique, with four fan setae, and numerous slender simple setae. Palp article 2 almost as long as wide, as wide as basis, lateral margin 1.5 as long as medial margin; article 3 0.6 as wide as article 2, as long as article 2 medially and 0.25 as long laterally, medial margin straight, with 12 setulated setae; article 4 2.15 as long as article 3 laterally, medial lobe half as short as and twice as broad as article 5, with five simple distal setae article 5 with four setae; lateral margin of basis, articles 1 and 2 with dense row of fine setae; epipod 3.4 as long as wide, 0.9 as long as basis, tip rounded. Pereopod 1 (Fig. 14A) ratios of lengths of ischium–carpus to basis: 0.25, 0.15, 1.0, propodus and dactylus broken off. Pereopods 2–4 broken off, basis of pereopod 4 longest. Pereopods 5 and 6 (Fig. 14B, C) ischii-carpi similar, carpi with dorsal plumose setae almost twice as long as ventral, propodi with plumose setae on both margins of the same length, dorsal margin with few whip setae. Pereopod 5 (Fig. 14B) basis shortest and broadest, ratios of lengths of ischium– propodus to basis: 0.8, 0.35, 1.9, 1.75, carpus 2.4 times as long as wide, 2.2 times as wide as basis, propodus 7.1 times as long as wide, dactylus broken off.

Pereopod 6 (Fig. 14C) ratios of lengths of ischium–carpus to basis: 0.5, 0.2, 1.2, carpus 3.0 times as long as wide and 2.2 times as wide as basis, propodus and dactylus broken off. Pleopod 1 (Fig. 15A) 2 times as long as wide, each side ventrally with many small medial setae on distal third; distomedial lobes rounded with few setae, distolateral lobes acute, curved inside as claws twice longer than medial lobes. Pleopod 2 (Fig. 15A, B) length 1.6 pleopod 1 length. Protopod length 1.45 width (without ventromedial projection), ventromedial projection situated at mid length, length 0.2 protopod width. Protopod lateral margin with small plumose setae, projection and ventral surface of protopod with many small tubercles, scales and setae. Endopod stylet half as long as protopod, inserted proximomedially, exopod not reaching furrow between articles of endopod. Pleopod 3 (Fig. 15C) endopod 1.7 times as long as wide, 3 plumose setae on distomedial corner, length 0.3 endopod length, exopod 0.4 times as wide and 1.6 times as long as endopod, with row of fine simple lateral setae, apical article 0.5 times as long as basal one, with 3 plumose setae and 1 simple small seta distally. Pleopod 4 (Fig. 15D) endopod 1.5 as long as wide, with rounded distomedial tip, exopod 0.6 as long and 0.25 times as wide as endopod, with small distal seta. Pleopod 5 (Fig. 15E) 1.3 times as long as wide. Uropod unknown. Female (Fig. 11A–C). Antenna 1 (Figs 12D) length 0.15 body length, of 8 articles, article 1 length 1.85 width, distal lobe tapering; article 2 as long as article 1 distal lobe, length 1.4 width, widening distally; articles 2–8 length 0.3, 0.2, 0.1, 0.4, 0.2, 0.2, 0.2 article 2 length. Pleopod 2 (Fig. 11C) length 1.2 width, ventral spine short.

Etymology: The species name is feminine and refers to the type locality of the species.

Remarks: A. galaica sp. nov. is most similar to A. spinicauda Beddard, 1885 as described and illustrated by Wolff (1962, p. 111, 112) with regard to the general shape of the pleotelson, as well as the position and direction of its lateral spines. The species are similar regarding the size and shape of the slender lateral spines of pereonites 5–7, the coxal spines of pereopods 2– 4, and the antennal articles 2 and 3. A. galaica sp. nov differs from A. spinicauda in having a more elongate pleotelson: length without terminal spine 1.05 width without lateral spines in

contrast to 1.4 in A. spinicauda; in A. galaica sp. nov. the lateral margin of the pleotelson between the lateral spines is almost straight whereas it is more convex in A. spinicauda. Pereopods 5 and 6 of A. galaica sp. nov. have broader carpi than in A. spinicauda (carpi L/W are 2.4 and 3.0 in A. galaica sp. nov. and 5.5 and 5.8 in A. spinicauda). Distribution: Northeastern Atlantic, Galicia Bank, depth 1669‒1726 m. Known only from the type locality.

Acanthocope annulatus Menzies, 1962 (Fig. 16) Acanthocope annulatus Menzies, 1962: 155, Fig. 44 B, C; Malyutina and Brandt, 2004: 11, Figs 6‒10. Material examined: 1 male (5.9 mm TL), ZMH K–46199, Puerto Rico Trench abyssal area, RV Sonne, VemaTRANSIT cruise, 25 January 2015, C-EBS, station 14-1, 19º1.63’N 67º9.73’W, 4552‒4552 m depth, supranet, bottom temperature: 2.25ºC, bottom O2: 261.13 μM, bottom current: 5.25 cm/s.

Remarks: The only specimen of the species, found at the same station as A. puertoricana sp. nov., was identified as it has all described characters of the Acanthocope annulatus Menzies, 1962. This new record is located at more than 10000 km far away from the type locality in the southeastern Atlantic (SW of Cape Town). Future sampling in the Atlantic and genetic investigations might shed some light on the true distribution of this species.

Acanthocope eleganta Malyutina and Brandt, 2004 (Fig. 17) Acanthocope eleganta Malyutina and Brandt, 2004: 4, Figs 2–5. Material examined: 1 female, manca (3.2 mm TL), ZMH K–46200, Puerto Rico Trench abyssal area, RV Sonne, Vema-TRANSIT cruise, 25 January 2015, C-EBS, station 14-1, 19º1.63’N 67º9.73’W, 4552‒ 4552 m depth, supranet, bottom temperature: 2.25ºC, bottom O2: 261.13 μM, bottom current: 5.25 cm/s.

Remarks: The single specimen of the species, found in the same sample with the new species, seems to belong to Acanthocope eleganta as it fits to the species diagnostic characters, despite it is not mature specimen, but a juvenile on stage 3 of development.

Acanthocope galatheae Wolff, 1962 Acanthocope galatheae Wolff, 1962: 113, Figs 63‒65; Malyutina, 1999: 323, Fig.3; Schmidt et al., 2002: 87, Fig. 1 a-d and electronic Suppl. 1:2, Figs 1–11; Malyutina and Brandt, 2004: 19. Material examined: 25 specimens, ZMH K-46908, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 26 December 2014, C-EBS, station 4-8, 10º24.96’N 31º5.19’W, 5778‒5725 m depth, bottom temperature: 2.31ºC, bottom O2: 238.3 μM, bottom current: 6.6 cm/s. 7 specimens, ZMH K-46909, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 27 December 2014, C-EBS, station 4-9, 10º24.94’N 31º3.83’W, 5764‒5733 m depth, bottom temperature: 2.31ºC, bottom O2: 238.0 μM, bottom current: 2.0 cm/s. 57 specimens, ZMH K-46910, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 2 January 2015, C-EBS, station 6-7, 10º21.33’N 36º55.93’W, 5102‒5079 m depth, bottom temperature: 2.29ºC, bottom O2: 245.8 μM, bottom current: 2.4 cm/s. 32 specimens, ZMH K-46911, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 2 January 2015, C-EBS, station 6-8, 10º22.25’N 36º56.05’W, 5137‒5127 m depth, bottom temperature: 2.21ºC, bottom O2: 245.4 μM, bottom current: 2.1 cm/s. 12 specimens, ZMH K-46912, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 6 January 2015, C-EBS, station 8-4, 10º43.00’N 42º40.67’W, 5177‒5178 m depth, bottom temperature: 1.81ºC, bottom O2: 239.1 μM, bottom current: 2.6 cm/s. 8 specimens, ZMH K-46913, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 11 January 2015, C-EBS, station 9-2, 11º40.58’N 47º58.93’W, 4981‒4986 m depth, bottom temperature: 1.79ºC, bottom O2: 240.9 μM, bottom current: 6.1 cm/s. 2 specimens, ZMH K-46914, Vema Fracture Zone, RV Sonne, Vema-TRANSIT cruise, 12 January 2015, C-EBS, station 9-8, 11º39.37’N 47º54.96’W, 5004‒5001 m depth, bottom temperature: 1.80ºC, bottom O2: 241.6 μM, bottom current: 2.2 cm/s. Remarks: Though the new records are quite far from the type locality (Gulf of Panama), the collected specimens have been identified as Acanthocope galatheae as morphologically they fit to the description of A. galatheae, that was also confirmed by molecular genetic methods (Bober et al, this issue). This widely distributed morphotype was in the samples of many recent deep-sea expeditions in different regions of the world (see Appendix 1).

Key to the species of Acanthocope Modified after Chardy (1972); distributional data according to Beddard (1885), Menzies (1956, 1962), Wolff (1962), Birstein (1970), Chardy (1972), Menzies and George (1972), Müller (1989), Malyutina (1998, 1999), Schmidt et al. (2002), Malyutina and Brandt (2004, 2015), present study.

1.- Coxal spines of pereopods 2‒4 fused with pereonites 2‒4 lateral margins . . . . . . . . . . . . . . . . . . . . 2 - Coxal spines of pereopods 2‒4 separated from pereonites 2‒4 lateral margins . . . . . . . . . . . . . . . . . . 4 2.- Pereonites 5‒7 with paired dorsal spines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 3 - Pereonites 5‒7 without dorsal spines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. unicornis Menzies, 1962 NE Atlantic (between Meteor seamounts) and S Atlantic (Argentine Basin and E Walvis Ridge) 3760‒4339 m 3.- Pleotelson with dorsomedial round-topped keel and spine, lateral spines directed outwards, terminal spine absent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. curticauda Birstein, 1970 NW Pacific (Kuril-Kamchatka Trench) 4690‒4720 m - Pleotelson without dorsomedial keel and spine, lateral spines directed forwards, terminal spine present. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. galatheae Wolff, 1962 N and S Atlantic, SO (Atlantic sector) and N Pacific (Gulf of Panama and Kuril-Kamchatka Trench) 2149‒5778 m 4.- Pereonites 2‒4 without dorsomedial spine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - Pereonites 2‒4 with dorsomedial spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.- Posterolateral spines on pleotelson pointing forwards. Mandibular palp of 2 articles, last article longest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. spinosissima Menzies, 1956 NW Atlantic (Caribbean Sea) 1243.6 m - Posterolateral spines on pleotelson pointing backwards. Mandibular palp of 3 articles, last article no longer than preceding one . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. acutispina Beddard, 1885 SE Pacific (SW of Valparaiso) 2651.8 m 6.- Pleotelson with anterodorsal spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - Pleotelson without anterodorsal spine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 7- Pleotelson with dorsomedial keel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - Pleotelson without dorsomedial keel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.- Pereonites 5‒7 with broad lateral projections, pleotelson anterolateral spines broad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. puertoricana sp. nov. NW Atlantic (Puerto Rico Trench) 4522‒4522 m - Pereonites 5‒7 with slender lateral projections, pleotelson anterolateral spines slender. . . . . . . . . . . .9 9.- Pereonites 5‒7 with a pair of anterodorsal spines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 - Pereonites 5‒6 with a pair of short anterodorsal spines, pereonite 7 only with medial row of spinules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. eleganta Malyutina and Brandt, 2004

N Atlantic (between Meteor seamounts and Puerto Rico Trench) and SO (Atlantic sector) 2893‒4552 m 10.- Stout anterodorsal spines on pereonites 5‒7, pleotelson lateral spines backwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. galaica sp. nov. NE Atlantic (Galicia Bank) 1669‒1726 m - Long anterodorsal spines on pereonites 5‒7, pleotelson lateral spines outwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. orbus Menzies and George, 1972 SE Pacific (Perú-Chile Trench) 3167‒3318 m 11.- Pereonites 1‒4 dorsomedial spine long, directed upwards and forward; pleotelson with long dorsomedial spine anteriorly, posterolateral spines backwards . . . . . . . . . A. spinicauda Beddard, 1885 SO (Atlantic and Indian sector) 3291.8‒4931 m - Pereonites 2‒4 dorsomedial spine short, curved forward; pleotelson with small dorsomedial spine anteriorly, posterolateral spines forwards . . . . . . . . . . . . . . . . . . . . . . . . A. mendeleevi Malyutina, 1998 SW Pacific (New Caledonian Basin) 3400‒3410 m 12.- Pereonite 1 with short dorsomedial spine directed upwards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 - Pereonite 1 without dorsomedial spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 13.- Pereonite 5 with paired anterodorsal tubercles . . . . . . . . . . . . . . . . . . . A. annulatus Menzies, 1962 NW Atlantic (Puerto Rico Trench) and SE Atlantic (Cape Basin) and SO (Atlantic sector) 3689‒5055 m - Pereonite 5 with paired anterodorsal spines. . . . . . . . . . . . . . . . . . .. . . . . A. argentinae Menzies, 1962 SW Atlantic (Argentine Basin) 4602‒5024 m 14.- Pereonites 2‒4 dorsomedial spine long and slender, directed forwards . . . . . . . . . . . . . . . . . . . . .15 - Pereonites 2‒4 dorsomedial spine small, directed upward. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 15.- Uropodal exopod present, pereonite 5 with paired very long anterodorsal spines . . . . . . . . . . . . .16 - Uropodal exopod absent, pereonite 5 with paired moderate long anterodorsal spines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. beddardi Malyutina, 1999 SW Atlantic (Argentine Basin) 3760 m 16.- Pleotelson with long ventral projections at uropodal basis, antenna 2 article 2 with long distolateral spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. muelleri Malyutina, 1999 NE Atlantic (between Meteor seamounts) and SW Atlantic (Argentine Basin) 3760‒4339 m - Pleotelson without ventral projections at uropodal basis, antenna 2 article 2 with short distolateral spine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. pentacornis Müller, 1989 W Indian Ocean (Gulf of Aden) 1830‒1837 m 17.- Pereonite 4 with long dorsal spine reaching posterior margin of head; pereonites 5‒7 with paired dorsomedial tubercles; pleotelson without dorsomedial keel. . . . . . . . . . . . . . . A. armata Chardy, 1972 NE Atlantic (off Ireland) 2456 m

- Pereonite 4 with small dorsal spine, subequal in length to spines of pereontes 2 and 3; pereonites 5‒7 with paired dorsomedial spines; pleotelson with dorsomedial keel . . . . . . . . . A. carinata Chardy, 1972 NW Atlantic (Labrador Basin) 3456 m

4. Geographical distribution of Acanthocope species

The geographical distribution of the genus Acanthocope is summarized in Fig. 18. According to that, 12 Acanthocope species are known from the northern hemisphere and 11 from the southern hemisphere. Only five species (A. annulatus, A. eleganta, A. galatheae, A. muelleri and A. unicornis) are reported from both hemispheres. A. armata, A. carinata, A. curticauda, A. galaica sp. nov., A. pentacornis, A. puertoricana sp. nov. and A. spinosissima are reported only in the northern hemisphere, whereas A. acustipina, A. argentinae, A. beddardi, A. mendeleevi, A. spinicauda and A. orbus are recorded in the southern hemisphere. Most of them are only known from one site, i.e. the type locality provided in their corresponding species description (see Table 1). The study of the Acanthocope species in the SO by Malyutina and Brandt (2004) provided the description of the most recent new species (prior to this study) for the genus and extended the distribution for A. annulatus and A. galatheae to southern latitudes, documenting a wide biogeographic range of the species beyond the type locality (Malyutina, 1999). The study of some abyssal S Atlantic basins within the framework of DIVA expeditions (Schmidt et al., 2002; Malyutina unpublished data) extended the distribution of A. eleganta, A. muelleri, A. unicornis and the widespread A. galatheae northward into the Atlantic Ocean, whereas for A. argentinae more records were added in its known distributional area (see Appendix 1). In the abyssal area of the Kuril-Kamchatka Trench, Malyutina and Brandt (2015) provided new records for A. galatheae in the NW Pacific and the occurrence of two other species, both putatively new to science. After the recent Vema-TRANSIT and BANGAL 0711 expeditions, five species of the genus Acanthocope have been recorded in the N Atlantic, two of them are herein described as new to science. In the present study, the records of A. galatheae in the Vema Fracture Zone confirm its occurrence at both sides of the Mid-Atlantic Ridge and within the transform fault, which connects the abyssal basins. The genetical analysis of A. galatheae supported the distribution of this species across the Mid Atlantic Ridge in the Vema area and reinforced the previous morphological identification of specimens (Bober et al., this issue). This evidence suggests there will be further records of A. galatheae and/or the other Acanthocope species in the N Atlantic when more studies in the deep-sea were carried out.

Furthermore, both A. annulatus and A. eleganta are herein reported confirming an amphiAtlantic distribution for these species. The frequent occurrence of the genus Acanthocope in the deep Atlantic Ocean is related to the sampling effort made in this region. Additional sampling in other oceans could provide more data for this genus to fill the gaps on its worldwide distribution. Acanthocope is a rare munnopsid genus but widely distributed in the deep sea, especially at bathyal and abyssal depths. A. galaica sp. nov., A. pentacornis and A. spinossima are strict inhabitants of the upper bathyal seafloor (see key to species), whereas A. acutispina, A. armata, A. beddardi, A. carinata, A. mendeelvi and A. orbus occurred in the lower bathyal. The remaining nine species extended their depth range into the abyssal regions. No records at hadal depth are currently known (Acanthocope specimens were not found in the hadal samples of the VemaTRANSIT expedition in the Puerto Rico Trench). A. galatheae shows the widest depth range of distribution (3629 m) of all species of Acanthocope (see key to species), followed by A. eleganta and A. spinicauda which exhibit a depth range of 1659 and 1639 m, respectively. A. galatheae is also the deepest registered species of Acanthocope (2149‒5778 m). The maximal depth of sampling was recorded in the N Atlantic at the Vema Fracture Zone (station 4-8). In contrast, A. spinosissima reported the shallower depth value (1243.6 m) in the Caribbean Sea.

5. Species richness of Acanthocope species

The highest diversity of the Acanthocope species is reported in the Atlantic Ocean, where 13 species occurred (Fig. 18). Five species have been recorded in the Pacific, four in the SO and two in the Indian Ocean. Rarely more than one species of Acanthocope have been collected at the same station. In the abyssal area of the Puerto Rico Trench three species of Acanthocope were found in the same sample (A. annulatus, A. eleganta and A. puertoricana sp. nov.; see Table 2, Appendix 1). Also in the N Atlantic, between the Great and Little Meteor seamounts, another four species of Acanthocope were found at the same station (A. eleganta, A. galatheae, A. muelleri and A. unicornis; see Appendix 1). In the S Atlantic A. beddardi, A. muelleri and A. unicornis also co-occurred at the same station (Malyutina, 1999), sharing two species with the northwards station between Meteor seamounts. More studies are required to draw biogeographic conclusions.

6. Ecological notes Munnopsid isopods are well known to be good swimmers (Wolff, 1962; Menzies, 1962; Thistle and Wilson, 1987; Hessler and Strömberg, 1989; Wilson, 1989; Gage and Tyler, 1999; Marshall and Diebel, 1995; Osborn, 2009). Their three pairs of posterior legs (pereopods 5‒7) are modified such that the carpus and propodus are broad and flat with plumose setae on the margins. These modifications allow them to be effective swimmers (Osborn, 2009). According to the data from the described species (Table 1), Acanthocope specimens have been collected by means of trawling devices hauled on the seafloor. During Vema-TRANSIT and INDEMARES BANGAL 0711 expeditions, the sampling was carried out by means two sledges operated in the near-bottom water layer, which avoids the collection of pelagic organisms, and equipped with two superimposed nets (see material and methods section). All specimens of A. puertoricana sp. nov., recorded in the abyssal area of the Puerto Rico Trench, were caught in the upper net of the sledge (supranet, see Brandt et al., 2013); together with A. annulatus and A. eleganta specimens. A. galaica sp. nov. was collected in both upper and lower nets of the sledge (see Frutos, 2006). According to this observation, we can conclude that the new species have a suprabenthic behavior, which was already demonstrated for the other co-occurring species in previous studies (Malyutina and Brandt, 2004; Brandt et al. 2007).

Conclusions In the present paper new data on the taxonomy, diversity, abundance and distribution of species of Acanthocope are shown. Two new species from the N Atlantic are described and updated distributional data of the currently known 18 species of Acanthocope are provided. In terms of abundance, a general trend revealed high abundances of species of Acanthocope in the tropical area of the Atlantic and low values in the S Atlantic and the SO. The morphological study of the specimens showed an extension of the distribution of some species of Acanthocope to areas located far from their type localities. Additional sampling and further supplementary genetic analyses could be helpful to understanding the distribution of these species.

Acknowledgements The material from the tropical Atlantic was collected and sorted during the VemaTRANSIT expedition with the RV Sonne with the financial support of the PTJ (German

Ministry for Science and Education), grant 03G0227A to Prof. Dr. Angelika Brandt, University of Hamburg. The authors are grateful to the crew of the RV Sonne for their valuable support during the Vema-TRANSIT expedition and to the many students who sorted the samples. The material from the Galicia Bank was collected during INDEMARES BANGAL 0711 cruise, funded by the European Commission LIFE+ “Nature and Biodiversity” program and included the INDEMARES project (07/NAT/E/000732); I. Frutos was awarded a José Castillejo Fellowship for mobility of early career researchers (Spain, Ministerio de Educación, Cultura y Deporte; CAS12/00359). We also thank to the crew of the RV Miguel Oliver and to all the participants on the INDEMARES BANGAL cruise for their assistance at sea during sampling. The taxonomic processing of the new species performed by M.V. Malyutina was supported by the Russian Scientific Foundation (project 14-50-00034). I. Frutos was supported by a Postdoctoral Fellowship from the Bauer Foundation (Germany). Karen Osborn and Courtney Wickel (National Museum of Natural History, Washington D.C.) are thanked for the loan of paratype specimens of Acanthocope orbus (#120953) from the Smithsonian collections. Laure Corbari and Paula Martin-Lefèvre (Muséum National d’Histoire Naturelle, Paris) kindly provided the holotype of Acanthocope carinata (MNHN_Is 5859) and A. armata (MNHN-Is 3352) to I. Frutos during her Synthesys stay at the Crustacean collection. We are thankful to Dr. Kelly Merrin for her kind proofreading and correcting English. We also thank Dr. Stefanie Kaiser and two reviewers for their comments that improved this manuscript.

Appendix 1 Number of individuals of Acanthocope species collected by means of a sledge which allows for calculating the abundance after estimation of the haul length. Acanthocope data from DIVA 1 expedition in Schmidt et al. (2002); from DIVA 2 and 3 expeditions, Malyutina unpublished data; from ANDEEP I–III, Malyutina and Brandt (2007); from KuramBio, Malyutina and Brandt (2015). DZMB: German Center of Marine Biodiversity. a:at the beginning of the haul. Ocea n, area

Depth Stat ion

(m)

ann ulat us

arge ele ntina gan e ta

gal gala aic thea e a

mu puert elle orica ri na

spini unic s s caud orni p. p. a s 1 2

Expedi tion

Dat e

BANG AL 0711 BANG AL 0711

29/ 07/ 11 07/ 08/ 11

samp ling botto m (m2)

Coordinat esa

Source of station data

Atlantic Ocean Galicia Bank TS 2'

1726‒ 1705

-

-

-

1

-

-

-

-

-

-

-

TS 9

1669‒ 1674

-

-

-

4

-

-

-

-

-

-

-

Meteor

98

136

42º57.97'N 12º00.52' W 42º57.55'N 11º59.39' W

present study present study

Seamounts 63 6 Puerto Rico Trench

4339‒ 4338

14- 4552– 4552 1 Vema Fracture Zone

-

1

-

-

1

1

-

-

20

-

3

-

-

4

-

-

2

-

-

-

-

DIVA 3

18/ 08/ 09

-

Vema TRANS IT

24/ 01/ 15

Vema TRANS IT Vema TRANS IT Vema TRANS IT Vema TRANS IT Vema TRANS IT Vema TRANS IT Vema TRANS IT

26/ 12/ 14 27/ 12/ 14 02/ 01/ 15 02/ 01/ 15 06/ 01/ 15 11/ 01/ 15 12/ 01/ 15

5778– 4-8 5725

-

-

-

-

25

-

-

-

-

-

-

4-9

5764– 5733

-

-

-

-

7

-

-

-

-

-

-

6-7

5102– 5079

-

-

-

-

57

-

-

-

-

-

-

6-8

5137– 5127

-

-

-

-

32

-

-

-

-

-

-

8-4

5177– 5178

-

-

-

-

12

-

-

-

-

-

-

9-2

4981– 4986

-

-

-

-

8

-

-

-

-

-

-

9-8

5004– 5001

-

-

-

-

2

-

-

-

-

-

-

2250

29°19.24'N 28°37.94' W

DZMB databas e

764

19°01.63'N 67°09.73' W

present study

1613

10º24.96’N 31º05.19’ W 10º24.94’N 31º03.83’ W 10º21.33’N 36º55.93’ W 10º22.25’N 36º56.05’ W 10º43.00’N 42º40.67’ W 11º40.58’N 47º58.93’ W 11º39.37’N 47º54.96’ W

4176

0°08.79'S 2°28.75'W

Brix et al. 2015

2520

0°13.27'S 2°29.91'W

Brix et al. 2015

3132

0°42.95'N 5°31.29'W

Brix et al. 2015

1440

0°40.49'N 5°29.71'W

Brix et al. 2015

3146. 9

22º20.0'S 03º18.3'E

2445. 9

22º19.9'S 03º17.8'E

5781. 5

18º19.4'S 04º39.7'E

5372. 9

17º06.2'S 04º41.7'E

4261. 5

16º18.1'S 05º27.2'E

2769. 6

16º14.3'S 05º26.8'E

Brandt et al. 2005 Brandt et al. 2005 Brandt et al. 2005 Brandt et al. 2005 Brandt et al. 2005 Brandt et al. 2005

1750

1900

1980

1400

1750

673

present study present study present study present study present study present study present study

Guinea Basin 634

5047

-

-

-

-

121

-

-

-

-

-

-

DIVA 2

645

5054

-

-

-

-

65

-

-

-

-

-

-

DIVA 2

896

5142

-

-

-

-

78

-

-

-

-

-

-

DIVA 2

5142

-

-

-

-

52

-

-

-

-

-

-

DIVA 2

907 Angola Basin

15/ 03/ 05 15/ 03/ 05 20/ 03/ 05 20/ 03/ 05

31 8

5128‒ 5144

-

-

-

-

14

-

-

-

-

-

-

DIVA 1

32 0

5147‒ 5126

-

-

-

-

1

-

-

-

-

-

-

DIVA 1

33 8

5520‒ 5398

-

-

-

-

11

-

-

-

-

-

-

DIVA 1

34 4

5518‒ 5585

-

-

-

-

4

-

-

-

-

-

-

DIVA 1

34 8

5389‒ 5387

-

-

-

-

42

-

-

-

-

-

-

DIVA 1

35 0

5389‒ 5389

-

-

-

-

56

-

-

-

-

-

-

DIVA 1

09/ 07/ 00 10/ 07/ 00 22/ 07/ 00 25/ 07/ 00 28/ 07/ 00 29/ 07/ 00

DIVA 2

04/ 03/ 05

1620

28°3.07'S 7°19.81'E

Brix et al. 2015

DIVA 3

06/ 08/ 09

2340. 0

03°57.49'S 28°04.67' W

DZMB databas e

Cape Basin 401 Brasilian Basin 60 5

5055

5188‒ 5174

1

-

-

-

-

-

-

-

1

5

-

-

-

-

-

-

-

-

-

-

-

-

58 0

5131‒ 5154

-

-

-

-

8

-

-

-

-

-

-

DIVA 3

58 3

5148‒ 5144

-

-

-

-

7

-

-

-

-

-

-

DIVA 3

55 4 Argentine Basin

4485‒ 4479

-

-

-

-

1

-

-

-

-

-

-

DIVA 3

53 3

4602‒ 4606

-

19

-

-

-

-

-

-

-

-

-

DIVA 3

53 4 Southern Ocean Atlantic sector

4608‒ 4605

-

13

-

-

-

-

-

-

-

-

-

DIVA 3

422

3689

8

-

2

-

-

-

-

-

-

-

-

ANDE EP I

438

3962

1

-

-

-

-

-

-

-

-

-

-

ANDE EP I

11 4-4

4482

-

-

2

-

-

-

-

-

-

-

-

ANDE EP I

13 1-3

3053

-

-

-

-

11

-

-

-

-

-

-

ANDE EP II

13 5-4

4678

-

-

-

-

9

-

-

-

-

-

-

ANDE EP II

13 6-4

4747

-

-

-

-

1

-

-

-

-

-

-

ANDE EP II

595

4655

-

-

-

-

1

-

-

-

-

-

-

ANDE EP III

789

2149

-

-

-

-

2

-

-

-

-

-

-

ANDE EP III

888

4931

-

-

-

-

14

-

-

2

-

-

-

ANDE EP III

9414

4891

-

-

-

-

5

-

-

-

-

-

-

ANDE EP III

11 0-8

4695

-

-

-

-

4

-

-

-

-

-

-

ANDE EP III

Pacific Ocean Kuril-Kamchatka Trench 5418 ‒ 1-10 5429 4859 ‒ 3-9 4863 5376 ‒ 5-9 5379 5216 ‒ 7-9 5223 5218 ‒ 7-10 5221 5125 ‒ 8-9 5140

-

-

-

-

1

-

-

-

-

-

-

Kuram Bio

-

-

-

-

-

-

-

-

-

3 4

-

Kuram Bio

-

-

-

-

1

-

-

-

-

-

-

Kuram Bio

-

-

-

-

2

-

-

-

-

1

-

Kuram Bio

-

-

-

-

1

-

-

-

-

-

1

Kuram Bio

-

-

-

-

1

-

-

-

-

-

-

Kuram Bio

30/ 07/ 09 30/ 07/ 09 22/ 07/ 09

15/ 07/ 09 16/ 07/ 09

27/ 01/ 02 03/ 02/ 02 17/ 02/ 02 06/ 03/ 02 10/ 03/ 02 12/ 03/ 02 14/ 02/ 05 22/ 02/ 05 27/ 02/ 05 02/ 03/ 05 10/ 03/ 02

30/ 07/ 12 05/ 08/ 12 11/ 08/ 12 17/ 08/ 12 17/ 08/ 12 20/ 08/ 12

3069. 2

14°58.91'S 29°56.49' W 14°59.41'S 29°56.57' W 26°34.70'S 35°12.79' W

2912. 5

36°0.20'S 49°1.96'W

2979. 2

36°0.61'S 49°1.54'W

2824. 2 2430. 0

4766

4782

4482

3553

2773

5306

2878

2376

3488

3476

2904

2222

2840

2469

2994

2624

2840

59º40.32'S 57º35.64' W 60º27.19'S 56º04.81' W 61º43.51'S 60º44.43' W 65°19.99'S 51°31.23' W 65º59.97'S 43º00.82' W 64º01.54'S 39º06.88' W

DZMB databas e DZMB databas e DZMB databas e

DZMB databas e DZMB databas e

67°30.75'S 00°01.94'E 71°09.40'S 13°58.85' W 68°03.64'S 20°27.49' W 66°37.16'S 27°10.13' W 64°00.91'S 43°02.10' W

Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007 Brandt et al 2007

43°58.26'N 157°19.67' E 47°13.84'N 154°41.89' E 43°35.48'N 153°57.88' E 43°02.84'N 152°59.70' E 43°02.78'N 152°59.29' E 42°14.68'N 151°44.11' E

Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015

9-9

9-12

10-9

11-9

12-4

5399 ‒ 5408 5392 ‒ 5397 5248 ‒ 5265 5362 ‒ 5362 5215 ‒ 5228

-

-

-

-

1

-

-

-

-

-

-

Kuram Bio

-

-

-

-

-

-

-

-

-

1

1

Kuram Bio

-

-

-

-

2

-

-

-

-

-

2

Kuram Bio

-

-

-

-

1

-

-

-

-

1

-

Kuram Bio

-

-

-

-

-

-

-

-

-

2

-

Kuram Bio

23/ 08/ 12 24/ 08/ 12 26/ 08/ 12 29/ 08/ 12 31/ 08/ 12

2315

2377

2778

2408

2716

40°35.48'N 150°59.92' E 40°35.51'N 150°59.86' E 41°12.46'N 150°05.64' E 40°13.26'N 148°06.23' E 39°43.80'N 147°10.88' E

Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015 Brandt et al. 2015

References Beddard, F.E., 1885. Preliminary notice of the Isopoda collected during the voyage of H.M.S. ‘Challenger' – Part II. Munnopsidae. Proceedings of the Zoological Society of London, 1885, 916–925. Beddard, F.E., 1886. Report on the Isopoda collected by H.M.S. ‘Challenger’, during the Years 1873–1876. Pt 2 Challenger Reports, 17, 1–178. Birstein J.A.,1970. New Crustacea Isopoda from the Kurile Kamchatka Trench. Academy of Sciences of the USSR. Proceedings of the Institute of Oceanology, 86, 308–356. Bober, S., Riehl, T., Brix, S., Brandt, A. Does the Mid-Atlantic Ridge affect the distribution of benthic crustaceans across the Atlantic Ocean ? Deep-Sea Research II, this issue. Brandt A., Brenke N., Andres H.G., Brix S., Guerrero-Kommritz J., Mühlenhardt-Siegel U., Wäagele J.W., 2005. Diversity of peracarid crustaceans (Malacostraca) from the abyssal plain of Angola Basin. Organisms, Diversity and Evolution, 5, 105–112. Brandt A., Brix S., Brökeland W., Choudhury, Kaiser S., Malyutina M., 2007. Deep-sea isopod diversity, abundance and endemism in the Atlantic sector of the Southern Ocean Results from the ANDEEP I-III expeditions. Deep-Sea Research II, 54, 1760–1775. Brandt A., Elsner N., Golovan, O., Malyutina, M.V., Riehl, T., Schwabe, E., Würzberg, L., Brenke, N., 2013. Epifauna of the Sea of Japan collected via a new epibenthic sledge equipped with camera and environmental sensor systems. Deep-Sea Research II, 86-87, 43–55. Brandt A., Elsner N., Malyutina, M.V., Brenke, N., Golovan, O.,Lavrenteva A.V., Riehl, T., 2015. Abyssal macrofauna of the Kuril–Kamchatka Trench area (Northwest Pacific) collected by means of a camera–epibenthic sledge. Deep-Sea Research II, 111:175–187. Brix S., Leese F., Riehl T., Kihara T.C. 2015. A new genus and new species of Desmosomatidae Sars, 1897 (Isopoda) from the eastern South Atlantic abyss described by means of integrative taxonomy. Marine Biodiversity, 45,7–61.

Chardy, P., 1972. Le genre Acanthocope (Isopode, Asellote): description de deux espèces nouvelles. Remarques taxonomiques et biogéographiques. Bulletin Mensuel de la Société Linnéenne de Lyon, 36, 379–393. Frutos, I., 2006. Las comunidades suprabentónicas submareales de la ría de La Coruña y plataforma continental adyacente (NW Península Ibérica). Tesis doctoral, Departamento de Zoología y Antropología Física, Universidad de Alcalá, 402 pp. Gage, J.D., Tyler, P.A. 1991. Deep-sea Biology. A Natural History of organisms at the deepsea floor. Cambridge, Cambridge University Press, 504 pp. Hessler, R.R., Strömber, J.O. 1989. Behaviour of janiroidean isopods (Asellota), with special reference to deep-sea genera. Sarsia 74, 145–159. Malyutina, M.V., 1998. Acanthocope mendeleevi: a new species of Munnopsidae (Crustacea, Isopoda, Asellota) from the New Caledonia Basin. Russian Journal of Marine Biology, 24 (5), 343–347. Malyutina, M.V., 1999 A new record of species of Acanthocope (Isopoda, Munnopsidae). Russian Journal of Marine Biology, 25 (4), 320–329. Malyutina, M.V., 2003. Revision of Storthyngura Vanhöffen, 1914 (Crustacea: Isopoda: Munnopsididae) with descriptions of three new genera and four new species from the deep South Atlantic. Organisms, Diversity & Evolution, 3, 245–252, Electr. Suppl. 13, 1–101. Malyutina, M.V., Brandt, A., 2004. Acanthocopinae (Crustacea: Isopoda: Munnopsididae) from the Southern Ocean deep sea with the description of Acanthocope eleganta sp. nov. Zootaxa, 550, 1–20. Malyutina, M.V., Brandt, A., 2007. Diversity and zoogeography of Antarctic deep-sea Munnopsidae (Crustacea, Isopoda, Asellota). Deep-Sea Research II, 54, 1790–1805. Malyutina, M.V., Brandt, A., 2015. Composition and distribution of Munnopsidae (Crustacea, Isopoda, Asellota), collected during KuramBio expedition 2012 from the Kuril-Kamchatka Trench area. Deep-Sea Research II, 111, 245–255. Marshall N.J., Diebel C. 1995. “Deep-sea spiders” that walk through the water. Journal of Experimental Biology, 198, 1371–1379. Menzies, R.J. 1956. New bathyal Isopoda from the Caribbean with observations on their nutrition. Breviora, 63, 1–10. Menzies, R.J., 1962. The isopods of abyssal depths in the Atlantic Ocean. Vema Research Series, 1, 79–206. Menzies, R.J. George, R. Y. 1972. Isopod Crustacea of the Peru-Chile Trench. Anton Bruun Report, 9, 1–124.

Müller, H.G. 1989. Acanthocope pentacornis n. sp. from the Deep Sea of the Gulf of Aden. Senckenbergiana Maritima, 20 (3/4), 125–129. Osborn K.J. 2009. Relationships within the Munnopsidae (Crustacea, Isopoda, Asellota) based on three genes. Zoologica Scripta, 38(6), 617–635. Schmid, C., Brenke, N.,Wägele, J.W., 2002. On abyssal isopods (Crustacea: Isopoda: Asellota) from the Angola Basin: Eurycope tumidicarpus n. sp. and redescription of Acanthocope galatheae Wolff, 1962. Organisms, Diversity & Evolution, 2, 87–88. Thistle D., Wilson G.D.F. 1987. A hydrodynamically modified, abyssal isopod fauna. DeepSea Research I, 34(1), 73–87. Wilson, G.D.F., 1989. A systematic revision of the deep-sea subfamily Lipomerinae of the isopod crustacean family Munnopsidae. Bulletin of the Scripps Institution of Oceanography, 27, i–xiii, 1–138. Wolff, T., 1962. The systematics and biology of bathyal and abyssal Isopoda Asellota. Galathea Reports, 6, 1–320.

Figure captions Fig. 1. Location of sampling stations where Acanthocope species were collected in the N Atlantic during Vema-TRANSIT (red dots) and BANGAL 0711 (yellow dot) expeditions.

Fig. 2. Acanthocope puertoricana sp. nov. A–D Male, holotype (ZMH K-46195); A, body dorsal view, B, lateral view; C, pleotelson, ventral view; D, uropod. E, F anterior part of female with eggs, paratype (ZMH K-46198); E, dorsal view; F, ventral view. Scale bar: 1 mm. For D scale bar: 0.2 mm

Fig. 3. Acanthocope puertoricana sp. nov. Female with eggs, paratype (ZMH K-46196): A, body dorsal view, B, lateral view; C, pleotelson, ventral view. Scale bar: 1 mm.

Fig. 4. Acanthocope puertoricana sp.nov. A, C, D, Male paratype (ZMH K-46197), B, female, paratype (ZMH K-46196): A, B antenna 1 with enlarged first four articles. Scale bar: 0.1 mm; C, D left and right mandibles. Scale bar: 0.2 mm.

Fig. 5. Acanthocope puertoricana sp. nov. Male, paratype (ZMH K-46197), mouthparts with enlarged details: A, maxilla 1; B, maxilla 2; C, maxilliped. Scale bar: 0.2 mm.

Fig. 6. Acanthocope puertoricana sp. nov. Male, paratype (ZMH K-46197): A–D pereopods 1–4. Scale bar: 0.2 mm.

Fig. 7. Acanthocope puertoricana sp nov. A, B, Male, paratype (ZMH K-46197): A, pereopod 5; B, pereopod 7; C, female, paratype (ZMH K-46196), uropod. Scale bar: 0.2 mm.

Fig. 8. Acanthocope puertoricana sp. nov. Male, paratype (ZMH K-46197): A, B, pleopods 1, 2, ventral view, C, D, pleopods 1, 2 lateral view. Scale bar: 0.5 mm.

Fig. 9. Acanthocope puertoricana sp. nov. Male, paratype (ZMH K-46197): A–C, pleopods 3–5. Scale bar: 0.5 mm.

Fig. 10. Acanthocope galaica sp. nov. A–D, Male, holotype (MNCN 20.04/10607): A, body dorsal view; B, lateral view; C, head, ventral view; D, pleotelson, ventral view. Scale bar 1 mm.

Fig. 11. Acanthocope galaica sp. nov. A–C, Female, paratype (MNCN 20.04/10608); A, body dorsal view, B, lateral view; C, pleotelson, ventral view; D–F, male, paratype (MNCN 20.04/10609) D, dorsal view; E, ventral view; F, head, frontoventral view. Scale bar: 1 mm.

Fig.12. Acanthocope galaica sp. nov. Male, holotype (MNCN 20.04/10607): A, antenna 1 and articles 1–4 of antenna 2; B, maxilla 1; C, maxilla 2; D, antenna 1 of female, paratype (MNCN 20.04/10608). Scale bar: 0.5 mm.

Fig. 13. Acanthocope galaica sp. nov. Male, holotype (MNCN 20.04/10607): A, right mandible; B, left mandible; C, maxilliped with enlarged distal margin of endite; D, maxilliped palp articles 3–5. Scale bar: 0.5 mm.

Fig. 14. Acanthocope galaica sp. nov. Male, holotype (MNCN 20.04/10607): A, pereopod 1; B, pereopod 5; C, pereopod 6. Scale bar: 0.5 mm.

Fig. 15. Acanthocope galaica sp. nov. Male, holotype (MNCN 20.04/10607): A, pleopods 1, 2; B, pleopod 2; C, pleopod 3; D, pleopod 4; E, pleopod 5. Scale bar: 0.5 mm

Fig. 16. Acanthocope annulatus Menzies, 1962. Female, (ZMH K-46199): A, body dorsal view, B, lateral view; C, natasome, ventral view. Scale bar: 1 mm.

Fig. 17. Acanthocope eleganta Malyutina and Brandt, 2004. Manca, female (ZMH K-46200): A, body dorsal view, B, lateral view. Scale bar: 1 mm.

Fig. 18. World distribution of species of Acanthocope. Data according to Beddard (1885), Menzies (1956, 1962), Wolff (1962), Birstein (1970), Chardy (1972), Menzies and George (1972), Müller (1989), Malyutina (1998, 1999), Schmidt et al. (2002), Malyutina and Brandt (2004, 2015); see also Appendix 1.

Tables captions

Table 1. List of all known species of Acanthocope with data on their geographic and bathymetric distribution. *new localities of the species with coordinates of the stations are in appendix N

species

author

coordinates

Depth, m

1

Acanthocope

Beddard, 1885

SO (Indian and Atlantic sectors) 50°01’S 05°123.04’E, *

3292‒

Beddard, 1885

SE Pacific, southwestern of Valparaiso 42°43’S 82°11’E

2650

Menzies, 1956

NW tropical Atlantic, Caribbean Sea (Jamaica) 16º59.1¨N 79º07.9’W

1243.6

Menzies, 1962

SE Atlantic 36°34’S 14°08’E, SO,

3689‒

spinicauda

4931

Type species 2

Acanthocope acutispina

3

Acanthocope spinosissima

4

Acanthocope

*

annulatus 5

Acanthocope argentinae

5055 Menzies, 1962

SW Atlantic Argentine Basin, 38°58.5’S 41°45’W; 36°12’S 46°10’W *

4602‒ 5024

6

Acanthocope

Menzies, 1962

unicornis 7

Acanthocope

Wolff, 1962

galatheae 8

Acanthocope

Birstein, 1970

SE Atlantic E Walvis Ridge 23°S 08°11’E, SW Atlantic Argentine Basin 31º35’S17º26’W, *

3760‒

NE tropical Pacific, Gulf of Panama 5°49’N 78°52’W, *

2149–

NW Pacific 44°17’S 149°33’E

4690‒

5778

curticauda 9

4720

Acanthocope

Chardy, 1972

NE Atlantic, off Ireland 53°54.9’ N 17° 51.8’ W

2456

Chardy, 1972

NW Atlantic, Labrador Basin 55°52.5’N 49°54.4’ W

3465

Menzies & George, 1972

SE Pacific, Peru-Chile Trench 8°42’S, 80°40’W

3167‒

Müller, 1989

NW Indian Ocean, Gulf of Aden 13°19.7’‒19.9’N 47°29.2‒31.81’E

1830‒

SW Pacific, New Caledonia Basin 29°28.5’S 164°55’W

3400‒

Malyutina, 1999

SW Atlantic, Argentine Basin 31°35’S 17°26’W

3760

Malyutina, 1999

SW Atlantic, Argentine Basin 31°35’S 17°26’W,

3760‒

*

4339

SO, NW Weddell Sea, 65°18.55'S 51°31.95'W, *

2893‒

armata 10

Acanthocope carinata

11

12

Acanthocope orbus

Acanthocope pentacornis

13

Acanthocope

Malyutina, 1998

mendeleevi 14

Acanthocope beddardi

15

Acanthocope muelleri

16

17

3318

1837

3410

Acanthocope

Malyutina &

eleganta

Brandt, 2004

Acanthocope

sp.nov.

NW tropical Atlantic, Puerto Rico Trench, 19º1.63’N 67º9.73’W

4552

sp. nov.

NE Atlantic, Galicia Bank, 42º57’N 12º00’W,

1669‒

4552

puertoricana 18

4339

Acanthocope galaica

1726

Table 2. Abundance (ind./1000 m2) of Acanthocope species recorded during different expeditions by means of a sledge. The towing distance of the sledge was calculated according to the methodology of each expedition (see Appendix 1). Table 2. Abundance (ind./1000 m2) of Acanthocope species recorded during different expeditions by means of a sledge. The towing distance of the sledge was calculated according to the methodology of each expedition (see Appendix 1). Ocean and area Atlantic Ocean Galicia Bank

Stat Depth annul argen eleg ion (m) atus tinae anta

TS 2' TS 9 Meteor Seamount

1726‒ 1705 1669‒ 1674

-

-

-

-

-

-

gal galat aica heae

10. 2 29. 4

mue lleri

puertor spinic unic sp sp auda ornis .1 .2 icana

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Expediti on

Date

BANGA L 0711 BANGA L 0711

29/0 7/11 07/0 8/11

s 636

4339‒ 4338

-

-

0.4

-

8.9

1.3

-

-

0.9

-

-

DIVA 3

18/0 8/09

-

Vema TRANSI T

24/0 1/15

Puerto Rico Trench 141 Vema Fracture Zone

4552– 4552

1.3

-

1.3

-

-

-

5.2

-

-

-

4-8

5778– 5725

-

-

-

-

14.3

-

-

-

-

-

-

4-9

5764– 5733

-

-

-

-

3.7

-

-

-

-

-

-

6-7

5102– 5079

-

-

-

-

28.8

-

-

-

-

-

-

6-8

5137– 5127

-

-

-

-

22.9

-

-

-

-

-

-

8-4

5177– 5178

-

-

-

-

6.9

-

-

-

-

-

-

9-2

4981– 4986

-

-

-

-

11.9

-

-

-

-

-

-

9-8

5004– 5001

-

-

-

-

1.2

-

-

-

-

-

-

Vema TRANSI T Vema TRANSI T Vema TRANSI T Vema TRANSI T Vema TRANSI T Vema TRANSI T Vema TRANSI T

5047

-

-

-

-

29.0

-

-

-

-

-

-

DIVA 2

5054

-

-

-

-

25.8

-

-

-

-

-

-

DIVA 2

5142

-

-

-

-

24.9

-

-

-

-

-

-

DIVA 2

5142

-

-

-

-

36.1

-

-

-

-

-

-

DIVA 2

-

-

-

-

4.4

-

-

-

-

-

-

DIVA 1

-

-

-

-

0.4

-

-

-

-

-

-

DIVA 1

-

-

-

-

1.9

-

-

-

-

-

-

DIVA 1

-

-

-

-

0.7

-

-

-

-

-

-

DIVA 1

-

-

-

-

9.9

-

-

-

-

-

-

DIVA 1

-

-

-

-

20.2

-

-

-

-

-

-

DIVA 1

09/0 7/00 10/0 7/00 22/0 7/00 25/0 7/00 28/0 7/00 29/0 7/00

0.6

-

-

-

0.6

-

-

-

-

-

-

DIVA 2

04/0 3/05

-

-

-

-

2.1

-

-

-

-

-

-

DIVA 3

-

-

-

-

2.8

-

-

-

-

-

-

DIVA 3

-

-

-

-

2.9

-

-

-

-

-

-

DIVA 3

06/0 8/09 30/0 7/09 30/0 7/09

-

-

-

-

0.3

-

-

-

-

-

-

DIVA 3

22/0

26/1 2/14 27/1 2/14 02/0 1/15 02/0 1/15 06/0 1/15 11/0 1/15 12/0 1/15

Guinea Basin 634 645 896 907

15/0 3/05 15/0 3/05 20/0 3/05 20/0 3/05

Angola Basin

350

5128‒ 5144 5147‒ 5126 5520‒ 5398 5518‒ 5585 5389‒ 5387 5389‒ 5389

401

5055

318 320 338 344 348

Cape Basin

Brasilian Basin

583

5188‒ 5174 5131‒ 5154 5148‒ 5144

554

4485‒

605 580

4479

7/09

Argentine Basin 533 534

4602‒ 4606 4608‒ 4605

-

6.5

-

-

-

-

-

-

-

-

-

DIVA 3

-

4.4

-

-

-

-

-

-

-

-

-

DIVA 3

15/0 7/09 16/0 7/09

3689

1.7

-

0.4

-

-

-

-

-

-

-

-

3962

0.2

-

-

-

-

-

-

-

-

-

-

4482

-

-

0.4

-

-

-

-

-

-

-

-

3053

-

-

-

-

3.1

-

-

-

-

-

-

4678

-

-

-

-

3.2

-

-

-

-

-

-

4747

-

-

-

-

0.2

-

-

-

-

-

-

4655

-

-

-

-

0.3

-

-

-

-

-

-

2149

-

-

-

-

0.8

-

-

-

-

-

-

4931

-

-

-

-

4.0

-

-

0.6

-

-

-

4891

-

-

-

-

1.4

-

-

-

-

-

-

4695

-

-

-

-

1.4

-

-

-

-

-

-

ANDEEP I ANDEEP I ANDEEP I ANDEEP II ANDEEP II ANDEEP II ANDEEP III ANDEEP III ANDEEP III ANDEEP III ANDEEP III

27/0 1/02 03/0 2/02 17/0 2/02 06/0 3/02 10/0 3/02 12/0 3/02 14/0 2/05 22/0 2/05 27/0 2/05 02/0 3/05 10/0 3/05

-

-

-

-

0.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

12 .0

-

-

-

-

0.4

-

-

-

-

-

-

-

-

-

0.7

-

-

-

-

0. 3

-

-

-

-

0.4

-

-

-

-

-

0. 4

-

-

-

-

0.4

-

-

-

-

-

-

-

-

-

-

0.4

-

-

-

-

-

-

-

-

-

-

-

-

-

0. 4

-

-

-

-

0.7

-

-

-

-

0. 4 0. 7

-

-

-

-

0.4

-

-

-

-

-

-

-

-

-

-

-

-

-

KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o KuramBi o

30/0 7/12 05/0 8/12 11/0 8/12 17/0 8/12 17/0 8/12 20/0 8/12 23/0 8/12 24/0 8/12 26/0 8/12 29/0 8/12 31/0 8/12

Southern Ocean Atlantic sector 422 438 114 -4 131 -3 135 -4 136 -4 595 789 888 9414 110 -8 Pacific Ocean KurilKamchatka Trench 110 3-9 5-9 7-9 710 8-9 9-9 912 109 119 124

5418‒ 5429 4859‒ 4863 5376‒ 5379 5216‒ 5223 5218‒ 5221 5125‒ 5140 5399‒ 5408 5392‒ 5397 5248‒ 5265 5362‒ 5362 5215‒ 5228

0. 4 0. 7

-

-