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Presentation made at the iAtlantic kick-off meeting in Edinburgh, Scotland, June 2019

Aurospio abranchiata sp. nov. Neal, Paterson & Soto (Figures 8 c, 10, 13, 14, Table 3) Prionospio sp B: Paterson et al., 2011 Material examined: 97 specimens examined in total. Holotype: Cascais canyon: RRS Charles Darwin, cruise 179, April���May 2006, St. 56823 # 2 2006.04.27, 38�� 18.01 ��� N, 09�� 47.02 ��� W, 3218 m, megacore (NHMUK 2015: 1043). Paratypes: Portuguese margin: Nazar�� canyon RSS Discovery 297 August 2005, St. 15755 # 1 39 �� 30.62 ���N, 09�� 56.19 ��� W, 3461 m, 3 individuals; St. 15760 #1, 39�� 30.02 ��� N, 09�� 56.17 ���W 3465 m, 5 individuals; St. 15762 #1, 39�� 30.02 ��� N, 09�� 56.22 ��� W, 3464 m, 2 individuals; St. 15758 #6, 39�� 34.99 ��� N, 10 ��19.00��� W, 4335 m, 5 individuals; St. 15765 #2, 39��35.00��� N, 10 �� 19.04 ��� W, 4336 m 4 individuals. RSS Charles Darwin cruise 179 April���May 2006, St. 56851 #1, 39�� 29.99 ��� N, 09�� 55.97 ��� W, 3517 m, 2 individuals; St. 56851 #2, 39�� 29.99 ��� N, 09�� 56.01 ��� W, 3517 m, 2 individuals. Set��bal canyon: RSS Charles Darwin cruise 179 April���May 2006, St. 56804 # 5 2006.04. 21 38 �� 09.27���N 09�� 36.93 ���W 3275m 8 individuals; St. 56804 # 6 2006.04. 21 38 �� 09.26���N 09�� 36.94 ���W 3275m, 10 individuals; St. 56806 # 1 2006.04. 21 38 �� 09.29���N 09�� 36.96 ���W 3275m, 10 individuals; St. 56810 # 1 2006.04. 23 38 �� 09.22���N 09�� 37.02 ���W 3224m, 1 individual; St. 56816 # 1 2006.04. 25 38 �� 09.27���N 09�� 36.94 ���W 3275m, 14 individuals; St. 56842 # 1 2006.05.0 5 38 �� 06.45���N 09�� 59.94 ���W 4482m, 2 individuals. Cascais canyon: RSS Charles Darwin cruise 179 April���May 2006, St. 56823 # 2 2006.04. 27 38 �� 18.01 ���N 09�� 47.02 ���W 3218m, 9 individuals; St. 56828 # 1 18.02 ���N 09�� 46.98 ���W 3199m, 1 individual. PA P: RRS Challenger II 79 May 1991: 52701 # 5 48 ��51.0���N 16 ��30.0���W, 4840 m, 1 individual. RRS Discovery D 222 September 1996: 12930 # 39 48 �� 49.95 ��� N, 16 �� 29.4 ��� W, 4840 m, 1 individual. RRS Discovery D 226 March 1998: 13077 #23, 48�� 49.28 ��� N, 16 �� 30.56 ��� W, 4844 m, 2 individuals. RRS Discovery D 229 July 1997: 13200 #20, 48�� 49.8 ��� N, 16 �� 29.62 ��� W, 4844 m, 2 individuals; 13200 # 47 48 �� 39.29 ��� N, 16 �� 30.27 ��� W, 4844 m, 1 individual. RRS Discovery D 231 March 1998: 13368 #36, 48�� 49.78 ��� N, 16 �� 30.17 ��� W, 4845 m, 2 individuals; 13368 #42, 48�� 50.08 ��� N, 16 �� 29.88 ��� W, 4844 m, 1 individual; 13368 #44, 48�� 49.7 ��� N, 16 �� 30.12 ��� W, 4844 m, 1 individual. Diagnostic features. Lack of branchiae, enlarged square-shaped notopodial lamellae on third segment; neuropodial lamellae largest on chaetiger 3 forming long, rectangular with rounded edges, wing-like structure which sometimes extends horizontally away from body. Description. Small and slender species, holotype incomplete with 45 segments, measuring 5.65 mm long for 45 segments and 0.2 mm wide (width at chaetiger 1). Colour in alcohol pale yellow. Body narrow and cylindrical, of uniform width throughout. Prostomium rounded, anterior margin entire, broadly rounded, prostomial peaks absent; short blunt caruncle, extending to anterior of chaetiger 1; eyes not observed. Peristomium well developed, ventrally and laterally distinct, dorsally partially fused to chaetiger 1, forming a collar around prostomium, without forming distinct lateral wings. Branchiae absent. Notopodial and neuropodial postchaetal lamellae reduced in chaetiger 1; notopodial lamellae on chaetiger 2 nearly square-shaped, meeting at midline and covering the dorsum in larger specimens but more widely separated in smaller ones (Fig. 11.2 a, 3 a); largest on chaetiger 3; lamellae large, nearly square, almost meeting at the midline, covering the entire dorsal surface of the segment in large specimens but not in smaller ones (Fig. 11.2 b, 3 b). Notopodial postchaetal lamellae on chaetigers 4���5 smaller, about half the size of those on chaetiger 3, changing from square to rounded shape from chaetiger 6 onwards, all well separated, not covering the dorsum (Fig 11.2 c, 2 d, 3 c, 3 d). Distinct dorsal crests from chaetiger 8���12. Interparapodial pouches absent. Neuropodial lamellae on chaetiger 2 square-shaped with rounded corners; on chaetiger 3 very large, rectangular with rounded edges (somewhat indented on outer rim), wing-like structure which sometimes extends horizontally away from body. The neuropodial postchaetal lamellae in other segments becoming more rounded and of similar size. Capillaries in two rows in both notopodia and neuropodia. Sabre chaetae present singly from chaetiger 10 in neuropodia; stout, strongly curved, no granulation. Neuropodial hooded hooks present from chaetiger 11���12, up to 4���5 par fascicle; at least five pairs of small teeth above the main fang; square-shaped primary hood, secondary hood present, rudimentary. Notopodial hooks present singly from chaetiger 38. Pygidium unknown. Methyl green pattern. Strong stain remains on sides of segments 5���17, even six months after staining. Remarks. The absence of branchiae together with the shape and size of both notopodial and neuropodial lamellae on third segment are diagnostic characteristics of this species. The absence of branchiae poses a difficulty in assigning this species to a genus with certainty. Within the Spionidae the genera Spiophanes Grube, 1860 and Spiogalea Aguirrezabalaga and Ceberio, 2005, are characterised by a lack of branchiae. However, the specimens described here do not belong to these genera because they lack modified, hook-like setae in the neuropodia of chaetiger 1, which are found in Spiophanes and the two chitinous plates surrounding the peristomium, which are characteristic of Spiogalea. The specimens also lack the characteristic arrangement of neuropodial chaetae found in the mid-chaetigers of Spiophanes described by Mei��ner & Hutchings (2003) and Mei��ner (2005). In overall appearance this species bears close resemblance to species belonging to the Prionospio complex. Our species does not seem to belong to either Paraprionospi o or Orthoprionospio based on the first segment having chaetae and the first chaetiger not being completely separated from peristomium usually found in Paraprionospi o and Orthoprionospio. The genus Streblospio can be eliminated because our specimens lack a ridge across chaetiger 1 and a prominent hood or collar across the dorsum of chaetiger 2; the form of the neuropodial multidentate hooks is also different. The problem of generic assignment arises when trying to determine whether the species belongs to the genus Aurospio or Prionospio. Aurospio was separated from Prionospio primarily on branchiae staring from third chaetiger, their shape, and that they are partially fused at their base to the notopodia. An additional character cited by Maciolek (1981) is the absence of a secondary hood in the hooks of Aurospio. Sigvaldadottir (1998) emphasised a lack of prostomial peaks, a short caruncle reaching to the anterior margin of chaetiger 1; pointed dorsal lamellae in mid-body segments, the absence of dorsal crests, and sabre chaetae starting on chaetiger 10 or earlier in her analyses of Prionospio. However, A. banyulensis (Laubier, 1966) and A. pilkensis (Wilson, 1990) do not have the branchiae fused to the base of the notopodia. Also, many species of Prionospio do not have secondary hoods in the neuropodial hooded hooks (Wilson 1990). Many of the characters highlighted by the cladistic analyses of Sigvaldadottir (1998) are actually also found in species of Prionospio. For example, short caruncles can be found in P. coorilla Wilson, 1990; P. pulchra Imajima, 1990; P. somaliensis Cognetti-Varriale, 1988; and P. vari gat a Imijima, 1990. Such overlap blurs the distinction between the genera and so we are left with the characters of the branchiae. Our species lacks these key characters. Thus it becomes difficult to place this new species into a genus. We do not believe that the absence of branchiae justifies erection of a new genus or subgenus within Prionospio ���complex, but provides further support for view of Wilson (1990) and Sigvaldadottir (1998) that the differentiation of genera/subgenera based primarily on branchial arrangement is not justified. Therefore, based on the overall body shape, shape of the prostomium and shape of the dorsal lamellae, particularly the pair associated with chaetiger 3, this new species most closely resembles the characters displayed by species of Aurospio. Aurospio dibranchiata, A. foodbancsia Mincks et al., 2008, and A. banyulensis appear to have large rectangular-shaped dorsal lamellae on chaetiger three, often orientated towards the mid-line. By contrast the dorsal lamellae of chaetiger 3 in Prionospio are usually described as foliose or auricular and pointed with a rounded tip. A. pilkena is an exception to this rule, having been placed in Aurospio presumably because the branchiae start on chaetiger 3. However, such characters have not been completely assessed by comparison with all other species of Prionospio and the assignment to Aurospio is principally by the general impression of the specimens, in particular the rounded shape of the prostomium. This is not a satisfactory conclusion. A major review of the generic boundaries, using molecular as well as morphological characters, will be needed to resolve this problem. Etymology. abranchiata ���refers to the absence of branchiae. Ecology. A. abranchiata sp. nov. was the second most abundant spionid species found in the canyons of the Iberian margin by the HERMES programme. However, it achieved higher densities in mid-depth canyons (around 3400 m) than in deep-water canyons with highest densities found in Cascais canyon, where it replaced P. vallensis sp. nov. as the most dominant spionid species. Cascais canyon is considered to be the most quiescent of the three canyons studied along the Portuguese margin. Cascais canyon also had the lowest abundance, but highest diversity and evenness, of polychaete assemblages. Aurospio abranchiata sp. nov. was also found in Set��bal canyon at 3400 m during RRS Discovery cruise 186 in 1989, where it was highly dominant, contributing nearly 30 % of the total polychaete abundance. The increased density during D 186 compared with densities recorded during the HERMES program is difficult to interpret as different mesh-sized sieves were used. A. abranchiata sp. nov. is a very slender species and larger numbers could have been caught in the 0.3 -mm mesh used during D 186 than in 0.5 -mm and 1 - mm mesh used during the HERMES sampling program. The species is also quite numerous in the sediment samples from the Porcupine Abyssal Plain where it reaches abundances of 40 individuals per metre 2. The absence of branchiae provides an interesting insight into evolutionary adaptations in these deep-sea spionids. The deep-sea species of Aurospio ��� A.dibranchiata, A.foodbancsia, and A. abranchiata sp. nov. show a reduction both in the size of branchiae and also in the number. A. dibranchiata has two pairs of small branchiae, A. foodbancsia has one pair while A. abranchiata sp. nov. has no branchiae. The absence of branchiae in A. abranchiata sp. nov. could be compensated by extremely large notopodial lamellae, which are also a diagnostic feature of this species. Distribution. Porcupine Abyssal Plain at 4800 m, Nazar��, Set��bal and Cascais canyons along Portuguese margin at 3199���4485 m., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 24-28, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio kaplani sp. nov. Altamira, Glover, & Paterson (Figure 1, 2.5, 7, 8b, Table 2) Material examined: 12 specimens examined. Holotype: CVAP: RSS Discovery October 1993, 12600 # 45 October 1993, 21�� 3.4 ���N 31 �� 9.8 ��� W, 4524 m, 1 individual (NHMUK 2015: 1190) Paratypes: Equatorial Pacific: 2 ��N 140 ��W, 4300 m, 4 individuals (EP 410, EP 425, EP 427, EP 444); 5 ��N 140 ��W 4300 m, 3 individuals (EP 431, 432, 473); 9 ��N 140 ��W, 4900 m, 1 individual (EP 414). MAP: RSS Discovery August 1990,12174#53, 31 5.2 ��� N 21 1.2 ��� W, 4942 m, 1 individual. Other material examined: CVAP: RSS Discovery October 1993,12600#28, 21�� 4.8 ��� N 31 �� 11.1 ��� W, 4613 m, 1 individual. Equatorial Pacific: EqPac 0��N 140 ��W, 4300 m, 1 individual (EP 488). Diagnostic features. Two pairs of branchiae on chaetigers 2 and 3, sabre chaetae lacking, dorsal crests from chaetiger 7, neuropodial hooded hooks from chaetiger 11. Description. Body cylindrical, narrow throughout; holotype 1.86 mm long for 20 chaetigers, (0.62 mm up to chaetiger 10); 0.08 mm wide at chaetiger 1. Prostomium rectangular with flat, entire anterior margin; one pair prostomial peaks present; caruncle short with rounded apex, extending to anterior margin of chaetiger 2. Eyes absent. Peristomium incomplete dorsally, not forming lateral wings, separate from chaetiger 1 (Fig 7 a). Branchiae from chaetiger 2, two pairs, very small. Branchiae on chaetiger 2 digitiform, blunt-tipped, inserted lateral and slightly posterior to dorsal lamellae; branchiae approximately one-half chaetiger long, subequal to notopodial lamellae; branchiae on chaetiger 3 conical, inserted posterior to dorsal lamellae and obscured by them, one quarter the length of lamellae (Fig. 2.5). Notopodial lamellae start on chaetiger 2, sub-quadranular, slightly angled toward dorsal midline (Fig 2.5 a); largest on chaetiger 3, sub-quadrangular with slightly produced tips overlapping dorsal midline, three times as long as lamellae of chaetiger 2 (Fig 2.5 b); thereafter, notopodial lamellae decrease in size, becoming low and subtriangular by chaetiger 7. Dorsal crests present from chaetigers 7 to chaetiger 17 (Fig. 2.5 f chaetiger 14). Neuropodial lamellae start on chaetiger 1, papilliform, length equal to one-fifth chaetiger length; neuropodial lamellae on chaetigers 2���5 leaf-like, narrow with short tips; neuropodial lamellae largest on chaetiger 3, length equal to chaetiger length and nearly twice that of chaetiger 2, neuropodial lamellae thereafter decreasing in length and increasing in width, becoming broadly ovoid by chaetiger 9. Interparapodial pouches absent. Notochaetae limbate capillaries, long, inserted in two densely packed rows from chaetigers 2���8 with up to 12 chaetae per row; thereafter, notochaetae reduced in number and density; all notochaetae angle forward on chaetigers 1���8 and anterior row always with shorter. Neurochaetae smooth and limbate capillaries, inserted in two distinct rows to chaetiger 8, up to eight chaetae per row, anterior row always shorter; thereafter, number of chaetae decrease, rows become indistinct. Neuropodial sabre chaetae not observed through 20 chaetigers (all specimens incomplete). Neuropodial hooded hooks present from chaetiger 11; shaft narrow with slender main fang, surmounted by two to three fine small teeth in one row, up to six chaetae per fascicle, inner hood absent; notopodial hooded hooks not observed. Pygidium not observed. Methyl green pattern. Not observed. Remarks. The key feature of this species is the presence of only two pairs of branchiae, the apparent absence of sabre chaetae, dorsal crests occurring from chaetigers 7 to 17, and the hooded hooks starting on chaetiger 11. Two other species of Prionospio have only two pairs of branchiae: P. sexoculata Augener, 1923 and P. h er m es i a sp. nov. Prionospio kaplani sp. nov. differs from P. sexoculata because in the latter species all the branchiae are pinnate while in P. kaplani sp. nov. all are apinnate. P. h e r m e s i a sp. nov. is similar to P. kaplani sp. nov., but differs in the shape of the prostomium in particular, having a flat anterior margin as opposed to a rounded one as in P. hermesia sp. nov. (Fig. 7); the caruncle extends to anterior boundary of chaetiger 1 in P. h er m es i a, while in P.kaplani sp nov it extends to anterior boundary of chaetiger 2; the neuropodial lamellae in P. kaplani sp. nov. are rounded with extended tips while in P. h e r m e s i a sp. nov. they are merely rounded. Prionospio kaplani sp. nov. also resembles P. branchilucida sp. nov. in having similarly shaped branchiae, a similarly shaped prostomium, and the peristomium being separated from chaetiger 1. They differ in the number of pairs of branchiae, two in P. kaplani sp. nov. but three in P. branchilucida sp. nov.; the dorsal crests start on chaetiger 7 rather than 10; and the neuropodial hooded hooks start on chaetiger 11 rather than chaetigers 14���17 as in P. branchilucida sp. nov. Etymology. This species in named in honour of the Kaplan Foundation in grateful acknowledgement of their support. Distribution. Prionospio kaplani sp. nov. has been recorded from the central Pacific and NE Atlantic Oceans from depths of 4300���4942 m (Fig. 1)., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 15-18, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Aurospio tribranchiata sp. nov. Paterson & Soto (Figure 1, 8 d, 10, 11, 12, Table 3) Minuspio sp 4 Soto 2008: 89. Material examined: 33 specimens examined in total. Holotype: Porcupine Abyssal Plain, RRS Discovery D 229, July 1997, 13200 #20, 48�� 49.8 ��� N, 16 �� 29.62 ��� W, 4844 m, 1���3 cm, 0.3 mm (NHMUK 2015: 1199). Paratypes: Porcupine Abyssal Plain, RRS Challenger 79, May 1991, 52701#9, 48�� 51.6 ��� N, 16 �� 27.4 ��� W, 4842 m, 2 individual; 52701 #25, 48�� 50.4 ��� N, 16 �� 29.6 ��� W, 4844 m, 3 individuals; 52701 #47, 48�� 50.6 ��� N, 16 �� 29.9 ��� W 4841 m, 1 individual. Porcupine Abyssal Plain, RRS Discovery D 222, August 1996, 12930#14, 48�� 50.92 ���N, 16 �� 30.24 ���W, 4837 m, 1 individual; 12930 # 44, 4849.95 ���N, 1630.2 ���W, 4839 m, 1 individual; 12930 # 59, 4850.45 ���N, 1630.58 ���W, 4837 m, 1 individual; 12930 #68, 48�� 49.92 ���N, 16 �� 29.76 ���W, 4840 m, 2 individual; 12930 #73, 48�� 50.08 ���N, 16 �� 29.69 ���W 4839 m, 2 individuals. 1) Aurospio tribranchiata sp. nov. a) Chaetiger 2; b) Chaetiger 3; c) Chaetiger 4; d) Chaetiger 5; scale bar = 100 ��m. 2) Aurospio abranchiata sp. nov. from PAP a) Chaetiger 2; b) Chaetiger 3; c) Chaetiger 4; d) Chaetiger 5; e) Chaetiger 8; scale bar = 100 ��m. 3) Aurospio abranchiata sp. nov. from canyons a) Chaetiger 2; b) Chaetiger 3; c) Chaetiger 4; Chaetiger 5; scale bar = ��m. Porcupine Abyssal Plain, RRS Discovery D 226, March 1998, 13077#19, 4850���N, 1630.05 ���W, 4846 m, 4 individual; 13077 # 23, 4849.28 ���N, 1630.56 ���W, 4844 m, 1 individual; 13077 #59, 48 49.98 N, 16 29.96 W, 4845 m, 1 individual; 13078 #13, 48��50.00���N, 16 ��30.0���W, 4843 m, 1 individual. Porcupine Abyssal Plain, RRS Discovery D 229, July 1997, 13200 # 17, 4849.67 ���N, 1628.72 ���W, 4843 m, 2 individuals; 13200 #20, 48�� 49.8 ��� N, 16 �� 29.62 ��� W, 4844 m, 3 individuals; 13200 # 47, 4839.29 ���N, 1630.27 ���W, 4844 m, 1 individual; 13200 #52, 48�� 49.84 ���N, 16 �� 29.84 ���W, 4844 m, 2 individuals. Porcupine Abyssal Plain, RRS Discovery D 231, March 1998, 48 50.51 ���N 16 29.43 ���W, 4842 m, 1 individual; 13368 #25, 48�� 50.51 ���N, 16 �� 29.43 ���W, 3 individuals. Porcupine Abyssal Plain, RRS Discovery D 237 September 1998, 13627# 17, 4849.9 ���N, 16 49.9 ���W, 4837 m 2 individuals. Diagnostic features: three pairs of branchiae, first pair starting on chaetiger 3 and the last pair being much longer than the other two. Description. Small slender species with thorax widening posteriorly then staying the same width; holotype fragment with 20 chaetigers, 3.00 mm long; 0.18 mm wide at chaetiger 1 (not including the chaetae). Colour cream to pale yellow. Prostomium rounded to rectangular; caruncle long extending to anterior edge of chaetiger 2, well developed, then appearing to extend weakly beyond segment boundary. No eyes. Peristomium separated ventrally and laterally from chaetiger 1, fused dorsally forming a distinct rounded collar. Palps simple up to 5 chaetigers in length, no basal sheath. Branchiae present on chaetigers 3 to 5; all apinnate, cylindrical, tapering gradually to a rounded point; branchiae on chaetigers 3 and 4 short, about the same length as the accompanying dorsal lamellae; branchiae on chaetiger 5 long, up to five chaetigers in length and two to three times the length of the accompanying dorsal lamellae (Fig. 11.1 d; 12 a,c, 13 a,c. Chaetiger 1 with small rounded notopodial lamellae. Notopodial lamellae increase in size with the largest on chaetigers 4 and 5; lamellae triangular on chaetigers 2 and 3, becoming wider and more rounded on chaetigers 5 and 6. Notopodial lamellae in mid-body low and rounded. Dorsal crests low difficult to see but occur on chaetigers 9 to 12. Neuropodial lamellae on chaetiger 1 small rounded, increasing over chaetigers 2 to 9; lamellae largest on chaetiger 3 (Fig 12 b). Capillaries arranged on two rows on notopodia and neuropodia, capillaries bilimbate with those in the lower row slightly granulated. Sabre chaetae robust, curved, limbate, slightly or non-granulated, starting on chaetiger 10 or 11; one per fascicle. Neuropodia hooded hooks start on chaetiger 12, up to six per fascicle; two to three pairs of small teeth above the main fang (specimens small difficult to see the exact arrangement), no inner hood; Notopodial hooded hooks not observed. Pygidium unknown. Methyl green pattern. Band of stain across middle of prostomium or across whole prostomium, diffuse over body. Remarks. A. tribranchiata sp. nov. is assigned to Aurospio because the branchiae start on chaetiger 3. All specimens of A. tribranchiata, were carefully examined stained with Shirlastain A (SDL international. A textile fibre identification stain - very useful in revealing features, such as scars) and were not able to detect the presence of scars on any of our specimens. As further supporting evidence there was no branchial pair on chaetiger 2 or evidence of their scars even on otherwise complete specimens which had very long branchiae of chaetiger 4 (which could be easily lost) and palps (almost always lost in spionids) still attached. Based on current evidence we have assigned this species to Aurospio until proven otherwise. Other characters such as the shape of the prostomium, lack of an internal secondary hood in the hooded hooks also are common to species in this genus (but see Remarks in the previous species for a discussion on the problems of defining this genus). A. tribranchiata sp. nov. is similar to A. pilkena Wilson, 1990 and A. banyulensis (Laubier, 1963), in particular the form of the prostomium, having three pairs of branchiae (see Table 4). A. banyulensis also has dorsal crests starting on chaetiger 8, hooded hooks starting on chaetiger 12 and sabre chaetae on chaetiger 10. A. tribranchiata sp. nov. differs in the arrangement of the third pair branchiae which are long whereas on A. pilkena and A. banyulensis they are all the same size. A. longibranchiata differs from A. pilkena in the starting positions of the sabre chaetae and hooded hooks and having dorsal crests (see Table 4). Etymology. tribranchiata refers to the three pairs of branchiae found on this species. Ecology. A. tribranchiata sp. nov. is one of the dominant species of spionids found on the Porcupine Abyssal Plain, found in densities of between 4 and 24 individuals per m 2. This species was found within the sediment at depths between 0���5 cm. Distribution. This species has only been recorded from the Porcupine Abyssal Plain 48 ��N, 16 �� W (Northeast Atlantic Ocean) and from a depth of 4800 m., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 19-24, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio amarsupiata sp. nov. Neal & Altamira (Figures 1, 2.1, 3, 8e) Prionospio sp D Paterson et al. 2011: 2453. Material examined. 24 specimens examined. Holotype: Set��bal canyon RRS Charles Darwin 179. April���May 2006, St. 56842 #1, 38��06.45���N 9 �� 59.94 ���W, 4482 m (NHMUK 2015: 1042). Paratypes: Portuguese margin canyons: Nazar�� canyon RRS Discovery 297, August 2005, St. 15758 #2, 39�� 34.94 ��� N 10 ��19.00��� W, 4332 m, 2 individuals; St. 15765 #2, 39��35.00��� N, 10 �� 19.04 ��� W, 4336 m, 1 individual. RRS Charles Darwin 179, April���May 2006, St. 56861 # 1 39 �� 35.57 ��� N, 10 �� 20.02 ��� W, 4404 m, 1 individual. St. 56847 # 6 39 �� 35.57 ���N 10 �� 19.99 ���W 4403m, 1 individual. Set��bal canyon RRS Charles Darwin 179. April���May 2006, St. 56804 #5, 38��09.27���N 9 �� 36.93 ���W, 3275m, 1 individual; St. 56804 # 6 38 ��09.26���N 9 �� 36.94 ���W, 3275m, 3 individuals; St. 56806 #1, 38��09.29���N 9 �� 36.96 ���W, 3275m, 1 individual; St. 56838 # 2 38 ��06.50���N 9 �� 59.98 ���W, 4482m, 1 individual; St. 56842 #1, 38��06.45�����N 9 �� 59.94 ���W, 4482m, 3 individuals; Cascais canyon RRS Charles Darwin 179. April���May 2006, St. 56837 #8, 38�� 22.49 ���N 9 �� 53.52 ��W, 4244 m, 1 individual; St. 56821 #1, 38�� 17.96 ���N 9 �� 46.87 �����W, 3219m, 1 individual; St. 56823 #2, 38�� 18.01 ���N 9 �� 47.02 �����W, 3218m, 1 individual; St. 56828 #1, 38�� 18.02 ���N 9 �� 46.98 ���W, 3199m, 1 individual. Other material studied: Crozet Island RRS Discovery D 300, December 2005 ��� January 2006, site M6,15773#31, 49��01.92���S 51 �� 13.88 ���E, 4192 m, 1 individual. Site M5, 15773#18, 45�� 52.96 ��� S, 56 �� 23.78 ��� E, 4186 m, 1 individual. Kaplan CCFZ Central Site (IFREMER Nodinaut campaign): RV L���Atalante, May���June 2004 KAP 3, CRS 868 / MTB9, 14�� 3.093 ���N, 130 �� 4.7825 ���W, 5031m, individual KP397, 1 individual. EqPac: RV Thomas Thompson, November 1992, BC15, 5��N 140 W, 0-1cm, EP 436 1 individual Madeira Abyssal Plain: RRS Discovery, August 1990, 12174 3-5cm, 300 ��m: (MAST_Polychaete Intercalibration Project number���map 55), 1 individual. Cape Verde Abyssal Plain: RRS Discovery, October 1993, 12600 # 10 213.2 ���N 3111.0���W, 4543 m, MAST_cv7, 1 individual. Diagnostic features. Lack of interparapodial pouches, first branchial pair with only few pinnules at the base of branchiae. Description. Holotype incomplete with 42 segments, measuring 14.5 mm long for 42 chaetigers and 0.63 mm wide at chaetiger 1. Pale yellow colour in alcohol. Prostomium angular, bottle-shaped with broadly rounded anterior margin, prostomial peaks normally absent (but two small peaks observed in one of the CROZET specimens); slender caruncle extending to anterior margin of chaetiger 2 (Fig. 3 a); eyes not observed. Peristomium well developed, encircling prostomium closely like a collar, partially fused to chaetiger 1, forming low lateral wings (Fig 3.a). Four pairs of branchiae present on chaetigers 2���5. First pair longest, reaching to chaetiger 10, very slender and cylindrical, although slightly flattened near base and with slender, slightly curled tips; surface mostly smooth to slightly wrinkled (Fig. 2.1 a); very few (1���3) pinnules near base; fourth pair of branchiae similar to first pair but about half the length, apinnate, no rudimentary pinnules observed. Branchial pairs 2 and 3 short, fleshy, foliaceous, wider at base, tapering into somewhat swollen tip, laterally ciliated, both pairs slightly shorter than accompanying notopodial lamellae, in dorsal view both pairs covered by enlarged notopodial lamellae. All branchial pairs situated lateral and slightly posterior to notopodial lamellae. Anterior notopodial lamellae from chaetiger 2���20 (holotype) generally enlarged, subtriangular, largest on branchial segments, particularly on chaetigers 3 and 4; more narrow on chaetiger 5; from chaetiger 6 increasing in width, becoming nearly square by chaetiger 10; after chaetiger 20 greatly reduced in size, becoming flattened assuming broadly ovoid shape with sharp pointed dorsal end and broad round posterior ventral end (Fig. 2.1 e chaetiger 22). Dorsal crests on chaetigers 5���20. Neuropodial lamellae small on chaetiger 1, largest on branchial chaetigers, then gradually becoming reduced in size; lamellae on chaetiger 2 fan-shaped with rounded corners (Fig 2.1 a); lamellae on chaetiger 3 also fan-like possesing well developed ventral tip (Fig. 2.1 b); lamellae on chaetiger 4 rounded; lamellae on cheatiger 5 low, rectangular (Fig. 2.1 c); from chaetiger 6 more rounded ventrally, starting to assume broadly ovoid in shape with somewhat pointed ventral tip (Fig. 2 e���f); similarly shaped through chaetiger 42, with lamellae becoming more flattened and pointed both dorsally and ventrally (Fig. 2.1 f). Interparapodial pouches absent (Fig. 3 b). Notopodia in anterior region with four rows of dense, yellow-hued capillaries, anterior neuropodial capillaries arranged in two rows. Sabre chaetae and neuropodial hooks start on chaetiger 19 in holotype and other specimens of similar size, but on chaetiger 18 in smaller specimens. Sabre chaetae long, slender, gently curved, often broken; anterior half is lightly granulated; 1 to 2 per fascicle. Neuropodial hooks up to 10 per fascicle. Neuropodial hooks long, slender, with round, inflated primary hood and striated secondary hood; shaft very constricted just below multidentate head, with six pairs of small teeth above the main fang (Fig. 3 c,d). Notopodial hooks not present in 42 chaetigers. Pygidium unknown. Methyl green pattern. Prostomium, peristomium and the edge of notopodial and neuropodial lamellae on chaetiger 1���4 stained strongly, thereafter only edges of notopodial lamellae and dorsal crest with faint stain. Remarks. This species closely resembles Prionospio ehlersi Fauvel, 1928 in the shape of the prostomium and peristomium and the chaetiger where the sabre chaetae and neuropodial hooks appear; neuropodial hooded hooks and sabre chaetae begin on chaetigers 18���19 in P. amarsupiata sp. nov., which is within the range of their occurrence on chaetigers 18���22 in P. ehlersi. The major difference is in the small number of pinnules on first branchial pair and lack of pouches in Prionospio amarsupiata sp. nov. This feature has been encountered in specimens collected from Crozet as well as in Portuguese canyons, EqPac and PAP specimens. It seems likely, therefore, that reduction in number of pinnules is a real feature of this species rather than a loss of pinnules, damaged during the handling of the specimens Interestingly, a species identified as Prionospio cf. ehlersi but lacking pouches was reported by Blake (1983) from the deep sea in the Antarctic and Chile. In a later publication Blake (1996) concluded that: ������these widely scattered deep-sea records of a P. ehlersi -like species that lack interparapodial pouches represent at least one, yet undescribed species.��� It is likely that at least some of Blake���s specimens are P. amarsupiata sp. nov. In additional deep-sea material examined, Blake encountered a specimen that lacked pouches but had a full branchial set (first pair short and pinnate, pairs 2, 3, and 4 short, all the same length, thick, and apinnate). This particular specimen is clearly different from P. amarsupiata sp. nov. based on its branchial form. Some specimens collected from HERMES canyons were reproductive with eggs, the largest of which were approximately 70 microns in diameter. Etymology. amarsupiata, meaning ���lacking pouches���; from the Latin marsupium, a pouch; reference is to the lack of interparapodial pouches in this species. Distribution. This species is widespread in the deep sea; confirmed records indicate the species has been recorded from the Nazar��, Set��bal and Cascais canyons along the Portuguese margin (3199���4488 m), Crozet Island (3500 m), the Equatorial Pacific (EqPac), and the Northeast Atlantic (Cape Verde Abyssal Plain 4500 m, Madeira Abyssal Plain 4800 m)., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 5-8, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio vallensis sp. nov. Neal & Paterson (Figures 1, 2.2, 4, 8g) Prionospio sp G Curdia et al. 2004: Prionospio sp A Paterson et al. 2011: 2453 Material examined: 1035 specimens examined. Holotype: RRS Charles Darwin, cruise 179 April–May 2006, Setúbal canyon St. 56859 #1, 39° 35.58 ’N 10 °20.00’W 4418m, megacore (NHMUK 2015: 1040). Paratypes: Portuguese margin canyon: Nazaré canyon RRS Discovery 297 August 2005, St. 15755 # 1 39 º 30.62 ’N 09° 56.19 ’W 3461m, 175 individuals; St. 15760 # 1 39 º 30.02 ’N 09° 56.17 ’W 3465m, 54 individuals; St. 15762 # 1 39 º 30.02 ’N 09° 56.22 ’W 3464m, 103 individuals; St. 15758 # 2 39 º 34.94 ’N 10 °19.00’W 4332m, 26 individuals; St. 15758 # 6 39 º 34.99 ’N 10 °19.00’W 4335m, 65 individuals; St. 15765 # 2 39 º35.00’N 10 ° 19.04 ’W 4336m, 39 individuals. RRS Charles Darwin 179, April/ May 2006, St. 56847 # 6 39 ° 35.57 ’N 10 ° 19.99 ’W 4403m, 33 individuals; St. 56847 # 7 39 ° 35.55 ’N 10 ° 20.06 ’W 4404m 33 individuals; St. 56851 # 1 39 ° 29.99 ’N 09° 55.97 ’W 3517m, 36 individuals; St. 56851 # 2 39 ° 29.99 ’N 09° 56.01 ’W 3517m, 76 individuals; St. 56856 # 1 39 ° 29.95 ’N 09° 56.00’W 3519m, 40 individuals; St. 56856 # 2 39 °30.00’N 09° 55.98 ’W 3522m 49 individuals; St. 56859 # 1 39 ° 35.58 ’N 10 °20.00’W 4418m, 37 individuals; St. 56861 # 1 39 ° 35.57 ’N 10 ° 20.02 ’W 4404m, 44 individuals. Setúbal canyon: RRS Charles Darwin 179 April/ May 2006, St. 56804 # 5 38 °09.27’N 09° 36.93 ’W 3275m, 75 individuals; St. 56804 # 6 38 °09.26’N 09° 36.94 ’W 3275m, 48 individuals; St. 56806 # 1 38 °09.29’N 09° 36.96 ’W 3275m, 60 individuals; St. 56810 # 1 38 °09.22’N 09° 37.02 ’W 3224m, 23 individuals; St. 56816 # 1 38 °09.27’N 09° 36.94 ’W 3275m, 37 individuals. Cascais canyon: RRS Charles Darwin 179 April/ May 2006, St. 56821 # 1 38 ° 17.96 ’N 09° 46.87 ’W 3219m, 1 individual; St. 56823 # 2 38 ° 18.01 ’N 09° 47.02 ’W 3218m, 2 individuals; St. 56823 # 3 38 ° 17.99 ’N 09° 47.07 ’W 3219m, 2 individual; St. 56828 # 1 38 ° 18.02 ’N 09° 46.98 ’W 3199m, 3 individuals; St. 56837 # 7 38.3748 ° - 9.8920 °, 4243 m, 3 individuals. Other material studied: Prionospio laciniosa Maciolek, 1985; paratypes (USNM 67674 - 75). Diagnostic features. Wrinkled branchiae on chaetigers 2 and 5, rectangular prostomium, dorsal crests from chaetiger 6 extending to beyond chaetiger 20, distal ends of proximal dorsal lamellae bent toward the mid-line and produced into slender tips. Description. A small and slender species, holotype complete with 65 chaetigers, measuring 12.4 mm long and 0.25 mm wide at chaetiger 1. Colour in alcohol pale yellow. Prostomium rectangular for about 2 / 3 of length, then tapering into caruncle reaching to anterior margin of chaetiger 2; posterior portion surrounded by heavily ciliated nuchal organs (Fig. 4 a); anterior margin truncated (Fig. 4), prostomial peaks absent; eyes absent (1 pair of colourless eyes present in some specimens, positioned on prostomium just before caruncle, best observed on stained specimens). Peristomium well developed ventrally, forming distinct lateral wings; chaetiger 1 reduced, dorsally fused to peristomium. Branchiae present on chaetigers 2 –5, 4 pairs, all apinnate, but wrinkled (Fig. 4 b,c). First pair longest, reaching to the anterior margin of chaetiger 8, approximately six times longer than the corresponding notopodial lamellae, distinctly wrinkled with deep grooves, thickened at the base, then cylindrical, tapering into blunt tip (in some specimens the first pair rather slender, still wrinkled but without deep grooves, possibly regenerating), heavily ciliated; pair 4 similar to pair 1 but shorter, by a ratio of 1: 4, approximately four times longer than the corresponding notopodial lamellae; pairs 2 and 3 short and heavily ciliated, only slightly longer than notopodial lamellae, with wrinkled surface, fleshy and triangular, wider at base and tapering distally, both pairs are partially covered by enlarged notopodial lamellae; all branchiae free from notopodial lamellae, positioned laterally and slightly posteriorly in relation to inner edge of notopodial lamellae (branchial pairs 1 and 4 easily lost and missing in majority of specimens). Notopodial lamellae on chaetiger 1 well developed (Fig. 2.2 a), rounded with very produced tip pointed dorsally; lamellae largest on branchial segments, particularly on chaetigers 3 and 4, subtriangular and somewhat bent, with tips pointing to the midline of dorsum (Fig. 2.2 b,c), notopodial lamellae on chaetiger 6 becoming smaller; from chaetiger 7 lamellae small, triangular, pointed distally, often bent, in mid-body segments becoming low, globular (Fig. 2.2 d). Distinct dorsal crests present from chaetiger 6 and on subsequent chaetigers (Fig. 4 a) to beyond chaetiger 20. Interparapodial pouches absent. Neuropodial lamellae largest in branchial segments; small and rounded in chaetiger 1, neuropodia of chaetiger 2 square-shaped, similar in shape but with distinct tip pointing dorsally on chaetiger 3 (Fig. 2.2), in chaetigers 4 and 5 tip not protruded, lamellae square to slightly rounded in shape; from chaetiger 6 becoming small (low rising) and distinctly globular (Fig. 1.2 d). Anterior chaetae all capillaries, granulated, forming dense fascicles, arranged in two rows in both noto- and neuropodia, neuropodial capillaries become long in middle and posterior segments reaching over 4–5 chaetigers in length. Sabre chaetae first occur in neuropodia of chaetiger 10, up to two per fascicle, robust, curved, heavily granulated. Neuropodial hooks first occur on chaetiger 12 but occasionally start from chaetiger 13, up to eight per fascicle; primary hood inflated and somewhat rectangular in shape, secondary hood present and well developed; each hook with six pairs of smaller teeth sequentially reduced in size above the main fang. Notopodial hooks appear around segment 45 (holotype damaged in this section, all other specimens examined were incomplete and notopodial hooks not observed), two per fascicle, long and slender. Pygidium conical, without any appendages, but these might have been lost. Methyl green pattern. The borders of prostomium, including caruncle, peristomium, and dorsal crests on segments 12–20 stain strongly. Remarks. Prionospio vallensis sp. nov. is characterised by wrinkled branchiae on segments 2 and 5. Prionospio fauchaldi and P. laciniosa, both described by Maciolek, 1985, also possess wrinkled branchiae. Prionospio fauchaldi is recorded from the West Atlantic, SE coast of Africa in 530–4950 m and in the western Pacific in approximately 2500 to 3000 m (Blake et al. 2009), and P. laciniosa is recorded from the west coast of Africa at 527– 542m. Prionospio vallensis sp. nov. further resembles P. fauchaldi by having a similar shape of prostomium and peristomium, with sabre chaetae and neuropodial hooks starting in the same segments. The major differences are that in P. fauchaldi the first and fourth pair of branchiae are of the same length, while the first pair is longer than fourth in P. vallensis sp. nov.; sabre chaetae are slender in P. fauchaldi but robust in P. vallensis sp. nov.; and P. fauchaldi possesses extremely long capillaries on the third chaetiger, but these are lacking in P. vallensis sp. nov. Prionospio vallensis sp. nov. is most similar to P. laciniosa, which also has the first wrinkled pair of branchiae longer than the fourth, but differs from P. vallensis sp. nov. in having a triangular rather than rectangular prostomium and presence of distinct dorsal flaps, which were not seen in P. vallensis sp. nov. The dorsal crests in P. laciniosa are present only on chaetigers 5–13 while in P. vallensis sp. nov. they start on chaetiger 6 and continue beyond chaetiger 20. The shape of notopodial lamellae of the branchial region is also different, whilst subtriangular in both species, the distal ends are bent and directed to the middle and extend into slender tips in P. vallensis sp. nov., whereas in P. laciniosa this bend is less prominent and the tips are more robust. The sabre chaetae in P. vallensis sp. nov. are more robust and shorter than in P. laciniosa. The specimens of both species were of similar size, therefore these differences, particularly presence/absence of dorsal flaps are unlikely to be of result of different developmental stages. Etymology. vallensis from the Latin valles, meaning valley, the closest Latin expression for canyon. Ecology. P. vallensis sp. nov. was previously recorded from Setúbal canyon at 3400 m during the RRS Discovery cruise 186 in 1989; although not formally described, it was recorded as Spionidae H. It was the second most abundant species in that study. Examination of photographs of polychaete specimens collected in 1999 during OMEX II from Nazaré canyon and reported by Curdia et al. (2004) as Prionospio sp. G is likely to be Prionospio vallensis. It was reported as the most abundant macrofaunal species at 3514 m and 4141 m. Prionospio vallensis sp. nov. was the single most abundant polychaete in Portuguese canyons, achieving densities of 784 ind./m 2 in Setúbal canyon (3400 m) and up to 918 ind./m 2 in Nazaré canyon (3400 m) (Cunha et al. 2011; Paterson et al. 2011). The difference in the abundance between our study and previous ones may be a reflection of different sampling design used during RRS Discovery cruise 186, where macrofauna was sieved on 300 -micron mesh. However, it was not present in Portuguese canyon samples collected at 1000 m or on the Tagus Abyssal Plain, which is adjacent to Setúbal and Cascais canyons. It is possible that this is a deep canyon “specialist” able to utilize the organically enriched sediments found within the canyon (compared to similar noncanyon depths) and/or rapidly occupy sediments following frequent disturbances, which occur within canyons. Data from previous studies in these canyons (Gage et al. 1995; Curdia et al. 2004) suggest that P. vall ensis sp. nov. has been able to maintain high-density populations in Portuguese canyons on more than a decadal timescale (sampling in 1989, 1999, 2005, 2006). Distribution. Nazaré, Setúbal, and Cascais canyons along the Portuguese margin, 3199–4419 m.

Prionospio branchilucida sp. nov. Altamira, Glover, & Paterson (Figure 1, 2.3, 5, 8a, Table 2) Material examined: 41 specimens examined in total. Holotype: Kaplan Clarion-Clipperton Fracture Zone East Site, RV New Horizon, February, March 2003, BC 830 14 ˚ 55.85 N 119 �� 2.97 W 4076 m. specimen KP 77 (NHMUK 2015: 1118). Paratypes. Kaplan Clipperton-Clarion Fracture Zone East Site: RV New Horizon, February���March 2003, BC 847 15 �� 1.98 N 119 �� 0.02 W 4078 m, 1 individual. Kaplan CCFZ Central Site (IFREMER Nodinaut campaign): RV L���Atalante, May���June 2004, BC 876 /KGS 17 14 �� 3.4024 ���N 130 �� 5.5851 ���W 5012 m, 2 individuals (KP 319, KP 333; BC 877 /KGS 19 14 �� 2.9823 ���N 130 �� 5.6489 ���W 5027 m, 3 individuals (KP 338, KP 348), KP; BC 879 /KGS 26 14 �� 3.3980 ���N 130 �� 5.5828 ���W 5012 m, 1 individual (KP 368); BC 880 /KGS 27 14 �� 2.7524 ���N 130 �� 5.4972 ���W 5041 m, 1 individuals (KP 379); BC 878 /KGS 20 14 �� 3.4687 ���N 130 �� 5.5994 ���W 5012 m, 1 individual (KP 443). ABYSSLINE 0 1 CCFZ: RV Melville October 2013: Stn A, 1352.900 N 11628.0 W 4171 m, 1 individual (CRS 1493, BC_03, in 2-5 cm fraction); Stn C, 1347.601 N 11642.185 W 4081 m, 1 individual (CRS 1504, BC_05, in 0- 2 cm fraction); Stn G, 1345.727 N 11627.824 W 4110 m, 2 individuals (CRS 1529, BC_09, in 5-10 cm fraction); Stn I, 1345.001 N 11630.799 W 4036 m, 2 individuals (CRS 1532, BC_ 10, in 0-2 cm fraction); Stn J, 1354.113 N 11635.442 W 4163 m, 2 individuals (CRS 1542, BC_ 13, in 0-2 cm and 2-5 cm fractions); Stn L, 1343.597 11640.200 4160 m, 1 individual (CRS 1545, BC_ 14, 0-2 cm sub-sample). Equatorial Pacific (EqPac): RV Thomas Thompson: EqPac November 1992 BC 15 5 ��N 140 ��W m. 4 individuals Cap Verde Abyssal Plain: RSS Discovery 12600 # 10 September 1993, 0���1 cm, 21 �� 3.2 ��� N 31 �� 11.0��� W 4543 m, 4 individuals; 12600 # 28, October 1993, 0���1 cm, 21 �� 4.8 ��� N 31 �� 11.1 ��� W 4613 m, 1 individual; 12600 # 32, October 1993, 0���1 cm, 21 �� 3.6 ��� N 31 �� 10.0��� W 4545 m, 1 individual. Madeira Abyssal Plain: RSS Discovery 12174 # 11 August 1990, 1��� 3 cm, 31 �� 4.4 ��� N 21 �� 10.3 ��� W 4936 m, 1 individual; 12174 # 11 August 1990, 3��� 5 cm, 31 �� 4.4 ��� N 21 �� 10.3 ��� W 4936 m, 1 individual; 12174 # 16 August 1990, 0���1 cm, 31 �� 4.9 ��� N 21 �� 9.4 W 4947 m, 1 individual; 12174 # 16 August 1990, 1��� 3 cm, 31 �� 4.9 ��� N 21 �� 9.4 W 4947 m, 1 individual; 12174 # 43 August 1990, 3��� 5 cm, 31 �� 5.3 ��� N 21 �� 10.9 ��� W 4947 m, 1 individual; 12174 # 53 August 1990, 3��� 5 cm 31 �� 5.2 ��� N 21 �� 1.2 ��� W 4942 m, 1 individual; 12174 # 60, August 1990, 0���1 cm 31 �� 6.0��� N 21 �� 10.0��� W 4947 m, 2 individuals; 12174 # 60, August 1990, 1��� 3 cm 31 �� 6.0��� N 21 �� 10.0��� W 4947 m, 1 individual; 12174 # 60, August 1990, 3��� 5 cm 31 �� 6.0��� N 21 �� 10.0��� W 4947 m, 2 individuals. Other material studied. Kaplan Clipperton-Clarion Fracture Zone East Site: RV New Horizon, February��� March 2003, BC 822 14 �� 57.34 N 119 �� 1.18 W 4038 m, 1 individual; BC 834 14 �� 59.95 N 118 �� 58.07 W 3982 m, 1 individual; Diagnostic features. Two pairs of branchiae on chaetigers 2 and 3, sabre chaetae lacking, dorsal crests from chaetiger 7, neuropodial hooded hooks from chaetiger 11. Description. Body cylindrical, narrow throughout; holotype 1.86 mm long for 20 chaetigers, (0.62 mm up to chaetiger 10); 0.08 mm wide at chaetiger 1. Prostomium rectangular with flat, entire anterior margin; one pair prostomial peaks present; caruncle short with rounded apex, extending to anterior margin of chaetiger 2. Eyes absent. Peristomium incomplete dorsally, not forming lateral wings, separate from chaetiger 1 (Fig. 5 a). Branchiae from chaetiger 2, two pairs, very small. Branchiae on chaetiger 2 digitiform, blunt-tipped, inserted lateral and slightly posterior to dorsal lamellae (Fig. 5 c,d); branchiae approximately one-half chaetiger long, subequal to notopodial lamellae; branchiae on chaetiger 3 conical, inserted posterior to dorsal lamellae and obscured by them, one quarter the length of lamellae (Fig. 2.3 b) Notopodial lamellae start on chaetiger 2, sub-quadranular, slightly angled toward dorsal midline; largest on chaetiger 3, sub-quadrangular with slightly produced tips overlapping dorsal midline, three times as long as lamellae of chaetiger 2; thereafter, notopodial lamellae decrease in size, becoming low and subtriangular by chaetiger 7 (Fig. 2.3 f). Dorsal crests present from chaetigers 7 to chaetiger 17. Neuropodial lamellae start on chaetiger 1, papilliform, length equal to one-fifth chaetiger length; neuropodial lamellae on chaetigers 2���5 leaf-like, narrow with short tips; neuropodial lamellae largest on chaetiger 3, length equal to chaetiger length and nearly twice that of chaetiger 2, neuropodial lamellae thereafter decreasing in length and increasing in width, becoming broadly ovoid by chaetiger 9. Interparapodial pouches absent. Notochaetae limbate capillaries, long, inserted in two densely packed rows from chaetigers 2���8 with up to 12 chaetae per row; thereafter, notochaetae reduced in number and density; all notochaetae angle forward on chaetigers 1���8 and anterior row always with shorter. Neurochaetae limbate capillaries, inserted in two distinct rows to chaetiger 8, up to eight chaetae per row, anterior row always shorter; thereafter, number of chaetae decrease, rows become indistinct. Neuropodial sabre chaetae not observed through 20 chaetigers (all specimens incomplete, the longest fragment comprises 30 chaetigers). Neuropodial hooded hooks present from chaetiger 11; shaft narrow with slender main fang, surmounted by two to three fine small teeth in one row, up to six chaetae per fascicle, inner hood absent; notopodial hooded hooks not observed. Pygidium not observed. Methyl green pattern. Banding on subdistal portion of prostomium and distal portion of peristomium; partial banding on anterior chaetigers, beginning at bases of notopodial lamellae, and encircling venter Remarks. This species is characterised by the small translucent digitiform branchiae on chaetiger 2, having only three pairs of branchiae and by the lack of sabre chaetae. Few species of Prionospio have only three pairs of branchiae, a character more commonly found in the genus Paraprionospio. Only P. aucklandica Augener, 1923 has been recorded with three pairs but in that species the branchiae are all pinnate, dorsal crests occur only on chaetiger 7, and sabre chaetae are present from chaetiger 10. P branchilucida sp. nov. resembles P. h e r m e s i a sp. nov. in apinnate branchiae and double rows of anterior chaetae; the two species differ in the number of branchiae, the form of the first pair of branchiae, extent of caruncle, and relative size of branchiae and notolamellae (see Table 2). Etymology. branchia ���a gill and lucida ���meaning clear, referring to the transparency of the first pair of branchiae. Distribution. This species has been recorded from the Central Pacific, the Equatorial Pacific (EqPac), and the Madeira and Cap Verde Abyssal Plains in the Northeast Atlantic. Bathymetric distribution ranges from 4800 m to 5041 m., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 11-13, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio Malmgren, 1867, Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on page 4, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio hermesia sp. nov. Neal & Paterson (Figures 1, 2.4, 6, 8f, Table 2) Material examined: 9 specimens examined in total. Holotype: Set��bal canyon, RSS Charles Darwin 179, April���May 2006, St. 56804 #6, 38�� 09.26 N, 9 ��. 36.94 W, 3275 m (NHMUK 2015: 1041). Paratypes. Nazar�� canyon, RSS Discovery 297, August 2005, St. 15760 #1, 39�� 30.02 N, 09�� 56.17 W, 3465 m, 2 individuals; St. 15762 #1, 39�� 30.02 N, 09�� 56.22 W, 3464 m, 1 individual; St. 15758 #2, 39�� 34.94 N, 10 �� 19.00 W, 4332 m, 1 individual. Nazar�� canyon, RSS Charles Darwin 179, April/ May 2006, St. 56851 #1, 39�� 29.99 ��� N, 9 �� 55.97 ��� W, 3517m, 2 individuals. Set��bal canyon, RSS Charles Darwin 179, April/ May 2006, St. 56816 #1, 38��09.27��� N, 9.36.94���W, 3275m, 1 individual. Cascais canyon, RSS Charles Darwin 179, April/ May 2006, St. 56821 #2, 38�� 17.97 ��� N, 9 �� 46.89 ��� W, 3214m, 1 individual. Diagnostic features. Two pairs of branchiae; lack of sabre chaetae; hooded hooks bi- or tridentate. Description. Very small and slender species, holotype incomplete with 53 chaetigers, measuring 5.65 mm long and 0.08 mm wide at chaetiger 1. Colour in alcohol pale yellow. Body narrow and cylindrical, of uniform width throughout. Prostomium oval, anteriorly slightly rounded, prostomial margin entire, prostomial peaks absent, posteriorly elongated into short blunt caruncle, extending to anterior of chaetiger 1 (Fig. 6 a���b); eyes not observed. Peristomium well developed, ventrally and laterally distinct, dorsally partially fused to chaetiger 1, forming a collar around prostomium, without forming distinct lateral wings. Branchiae 2 pairs, on chaetigers 2 and 3, both pairs apinnate with surface smooth to slightly wrinkled (Fig. 6 a,b); first pair longest, very slender, cylindrical, at least twice the length of corresponding notopodial lamellae, inserted laterally to the base of notopodial lamellae, but not connected to it (Fig 6 a); second pair short, about half the length of corresponding notopodial lamellae and one-third the length of first branchial pair, attached near the base of notopodial lamellae (Fig. 2.4 b). Notopodial lamellae on chaetiger 1 not developed; lamellae small, subquadrangular on chaetiger 2; lamellae greatly enlarged on chaetiger 3, subtriangular, the distal tip bent and pointed to the midline of the dorsum (Fig. 2.4 b), in subsequent chaetigers notopodial lamellae reducing in size, becoming rounded. Dorsal chests from chaetiger 8 (Fig. 6 c) to approximately chaetiger 25. Neuropodial lamellae on chaetiger 1 not developed, thereafter well developed if small and rounded on all segments, with the exception of chaetiger 3, on which they are shifted dorsally (Fig. 2.4), enlarged (at least twice the size of neuropodial lamellae on other segments), oar-shaped, sometimes extending from body horizontally. Capillary chaetae particularly dense in anterior region, arranged in two rows in both noto- and neuropodia, capillaries in anterior row very long capillaries in posterior row shorter, all lightly granulated, limbate. Sabre chaetae absent. Neuropodial hooded hooks present from chaetiger 13 in holotype, from chaetiger 14 in other specimens, often only single hooks present at first but up to seven hooks per fascicle in subsequent chaetigers; primary hood rounded, tightly follows the head of the hooks, secondary hood present and well developed; some hooks bidentate with large main fang and smaller secondary tooth, others appear to be multidentate (at least tridentate) with main fang and at least two smaller teeth above, arranged in a single row. Notopodial hooks present singly from chaetiger 48. Pygidium unknown. Methyl green pattern: The anterior half of prostomium and peristomium stain strongly, the margins of the notopodial and neuropodial lamellae on chaetigers 4���14 stain less intensely. Remarks. The distinguishing feature of this species is that it has only two pairs of branchiae. This species has affinities with Prionospio branchilucida sp. nov. and P. kaplani sp. nov. from abyssal plains. Lack of sabre chaetae is unusual, but was encountered in all three species (P. hermesia sp. nov., P. branchilucida sp. nov., and P. kaplani sp. nov.). Further similarity with Prionospio kaplani sp. nov. is that it also possesses a combination of bidentate and multidentate hooks (1 + 3 combination), and these hooks also appear to be flattened in SEM images (unlike the chunky, more inflated style of hooks in other Prionospio species). In both species dorsal crests begin on segment 8, but only a single pair of very short branchiae on the second chaetiger was found in P kaplani sp. nov. compared with in P. hermesia sp. nov. Prionospio branchilucida sp. nov. has a prostomium similar to that of P. hermesia sp. nov. and has similar branchiae on the second chaetiger, but at least three pairs of branchiae were confirmed to be present in P. branchilucida sp. nov., hooks appear to be more like the usual shape found in Prionospio in SEM images, and the dorsal crests begin after chaetiger 8. Etymology. P. hermesia sp. nov. named after the research programme HERMES. Distribution. P. hermesia sp. nov. has been recorded from the Nazar��, Set��bal and Cascais canyons of the Portuguese margin at depths of 3214���4364 m., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 13-15, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio vallensis sp. nov. Neal & Paterson (Figures 1, 2.2, 4, 8g) Prionospio sp G Curdia et al. 2004: Prionospio sp A Paterson et al. 2011: 2453 Material examined: 1035 specimens examined. Holotype: RRS Charles Darwin, cruise 179 April���May 2006, Set��bal canyon St. 56859 #1, 39�� 35.58 ���N 10 ��20.00���W 4418m, megacore (NHMUK 2015: 1040). Paratypes: Portuguese margin canyon: Nazar�� canyon RRS Discovery 297 August 2005, St. 15755 # 1 39 �� 30.62 ���N 09�� 56.19 ���W 3461m, 175 individuals; St. 15760 # 1 39 �� 30.02 ���N 09�� 56.17 ���W 3465m, 54 individuals; St. 15762 # 1 39 �� 30.02 ���N 09�� 56.22 ���W 3464m, 103 individuals; St. 15758 # 2 39 �� 34.94 ���N 10 ��19.00���W 4332m, 26 individuals; St. 15758 # 6 39 �� 34.99 ���N 10 ��19.00���W 4335m, 65 individuals; St. 15765 # 2 39 ��35.00���N 10 �� 19.04 ���W 4336m, 39 individuals. RRS Charles Darwin 179, April/ May 2006, St. 56847 # 6 39 �� 35.57 ���N 10 �� 19.99 ���W 4403m, 33 individuals; St. 56847 # 7 39 �� 35.55 ���N 10 �� 20.06 ���W 4404m 33 individuals; St. 56851 # 1 39 �� 29.99 ���N 09�� 55.97 ���W 3517m, 36 individuals; St. 56851 # 2 39 �� 29.99 ���N 09�� 56.01 ���W 3517m, 76 individuals; St. 56856 # 1 39 �� 29.95 ���N 09�� 56.00���W 3519m, 40 individuals; St. 56856 # 2 39 ��30.00���N 09�� 55.98 ���W 3522m 49 individuals; St. 56859 # 1 39 �� 35.58 ���N 10 ��20.00���W 4418m, 37 individuals; St. 56861 # 1 39 �� 35.57 ���N 10 �� 20.02 ���W 4404m, 44 individuals. Set��bal canyon: RRS Charles Darwin 179 April/ May 2006, St. 56804 # 5 38 ��09.27���N 09�� 36.93 ���W 3275m, 75 individuals; St. 56804 # 6 38 ��09.26���N 09�� 36.94 ���W 3275m, 48 individuals; St. 56806 # 1 38 ��09.29���N 09�� 36.96 ���W 3275m, 60 individuals; St. 56810 # 1 38 ��09.22���N 09�� 37.02 ���W 3224m, 23 individuals; St. 56816 # 1 38 ��09.27���N 09�� 36.94 ���W 3275m, 37 individuals. Cascais canyon: RRS Charles Darwin 179 April/ May 2006, St. 56821 # 1 38 �� 17.96 ���N 09�� 46.87 ���W 3219m, 1 individual; St. 56823 # 2 38 �� 18.01 ���N 09�� 47.02 ���W 3218m, 2 individuals; St. 56823 # 3 38 �� 17.99 ���N 09�� 47.07 ���W 3219m, 2 individual; St. 56828 # 1 38 �� 18.02 ���N 09�� 46.98 ���W 3199m, 3 individuals; St. 56837 # 7 38.3748 �� - 9.8920 ��, 4243 m, 3 individuals. Other material studied: Prionospio laciniosa Maciolek, 1985; paratypes (USNM 67674 - 75). Diagnostic features. Wrinkled branchiae on chaetigers 2 and 5, rectangular prostomium, dorsal crests from chaetiger 6 extending to beyond chaetiger 20, distal ends of proximal dorsal lamellae bent toward the mid-line and produced into slender tips. Description. A small and slender species, holotype complete with 65 chaetigers, measuring 12.4 mm long and 0.25 mm wide at chaetiger 1. Colour in alcohol pale yellow. Prostomium rectangular for about 2 / 3 of length, then tapering into caruncle reaching to anterior margin of chaetiger 2; posterior portion surrounded by heavily ciliated nuchal organs (Fig. 4 a); anterior margin truncated (Fig. 4), prostomial peaks absent; eyes absent (1 pair of colourless eyes present in some specimens, positioned on prostomium just before caruncle, best observed on stained specimens). Peristomium well developed ventrally, forming distinct lateral wings; chaetiger 1 reduced, dorsally fused to peristomium. Branchiae present on chaetigers 2 ���5, 4 pairs, all apinnate, but wrinkled (Fig. 4 b,c). First pair longest, reaching to the anterior margin of chaetiger 8, approximately six times longer than the corresponding notopodial lamellae, distinctly wrinkled with deep grooves, thickened at the base, then cylindrical, tapering into blunt tip (in some specimens the first pair rather slender, still wrinkled but without deep grooves, possibly regenerating), heavily ciliated; pair 4 similar to pair 1 but shorter, by a ratio of 1: 4, approximately four times longer than the corresponding notopodial lamellae; pairs 2 and 3 short and heavily ciliated, only slightly longer than notopodial lamellae, with wrinkled surface, fleshy and triangular, wider at base and tapering distally, both pairs are partially covered by enlarged notopodial lamellae; all branchiae free from notopodial lamellae, positioned laterally and slightly posteriorly in relation to inner edge of notopodial lamellae (branchial pairs 1 and 4 easily lost and missing in majority of specimens). Notopodial lamellae on chaetiger 1 well developed (Fig. 2.2 a), rounded with very produced tip pointed dorsally; lamellae largest on branchial segments, particularly on chaetigers 3 and 4, subtriangular and somewhat bent, with tips pointing to the midline of dorsum (Fig. 2.2 b,c), notopodial lamellae on chaetiger 6 becoming smaller; from chaetiger 7 lamellae small, triangular, pointed distally, often bent, in mid-body segments becoming low, globular (Fig. 2.2 d). Distinct dorsal crests present from chaetiger 6 and on subsequent chaetigers (Fig. 4 a) to beyond chaetiger 20. Interparapodial pouches absent. Neuropodial lamellae largest in branchial segments; small and rounded in chaetiger 1, neuropodia of chaetiger 2 square-shaped, similar in shape but with distinct tip pointing dorsally on chaetiger 3 (Fig. 2.2), in chaetigers 4 and 5 tip not protruded, lamellae square to slightly rounded in shape; from chaetiger 6 becoming small (low rising) and distinctly globular (Fig. 1.2 d). Anterior chaetae all capillaries, granulated, forming dense fascicles, arranged in two rows in both noto- and neuropodia, neuropodial capillaries become long in middle and posterior segments reaching over 4���5 chaetigers in length. Sabre chaetae first occur in neuropodia of chaetiger 10, up to two per fascicle, robust, curved, heavily granulated. Neuropodial hooks first occur on chaetiger 12 but occasionally start from chaetiger 13, up to eight per fascicle; primary hood inflated and somewhat rectangular in shape, secondary hood present and well developed; each hook with six pairs of smaller teeth sequentially reduced in size above the main fang. Notopodial hooks appear around segment 45 (holotype damaged in this section, all other specimens examined were incomplete and notopodial hooks not observed), two per fascicle, long and slender. Pygidium conical, without any appendages, but these might have been lost. Methyl green pattern. The borders of prostomium, including caruncle, peristomium, and dorsal crests on segments 12���20 stain strongly. Remarks. Prionospio vallensis sp. nov. is characterised by wrinkled branchiae on segments 2 and 5. Prionospio fauchaldi and P. laciniosa, both described by Maciolek, 1985, also possess wrinkled branchiae. Prionospio fauchaldi is recorded from the West Atlantic, SE coast of Africa in 530���4950 m and in the western Pacific in approximately 2500 to 3000 m (Blake et al. 2009), and P. laciniosa is recorded from the west coast of Africa at 527��� 542m. Prionospio vallensis sp. nov. further resembles P. fauchaldi by having a similar shape of prostomium and peristomium, with sabre chaetae and neuropodial hooks starting in the same segments. The major differences are that in P. fauchaldi the first and fourth pair of branchiae are of the same length, while the first pair is longer than fourth in P. vallensis sp. nov.; sabre chaetae are slender in P. fauchaldi but robust in P. vallensis sp. nov.; and P. fauchaldi possesses extremely long capillaries on the third chaetiger, but these are lacking in P. vallensis sp. nov. Prionospio vallensis sp. nov. is most similar to P. laciniosa, which also has the first wrinkled pair of branchiae longer than the fourth, but differs from P. vallensis sp. nov. in having a triangular rather than rectangular prostomium and presence of distinct dorsal flaps, which were not seen in P. vallensis sp. nov. The dorsal crests in P. laciniosa are present only on chaetigers 5���13 while in P. vallensis sp. nov. they start on chaetiger 6 and continue beyond chaetiger 20. The shape of notopodial lamellae of the branchial region is also different, whilst subtriangular in both species, the distal ends are bent and directed to the middle and extend into slender tips in P. vallensis sp. nov., whereas in P. laciniosa this bend is less prominent and the tips are more robust. The sabre chaetae in P. vallensis sp. nov. are more robust and shorter than in P. laciniosa. The specimens of both species were of similar size, therefore these differences, particularly presence/absence of dorsal flaps are unlikely to be of result of different developmental stages. Etymology. vallensis from the Latin valles, meaning valley, the closest Latin expression for canyon. Ecology. P. vallensis sp. nov. was previously recorded from Set��bal canyon at 3400 m during the RRS Discovery cruise 186 in 1989; although not formally described, it was recorded as Spionidae H. It was the second most abundant species in that study. Examination of photographs of polychaete specimens collected in 1999 during OMEX II from Nazar�� canyon and reported by Curdia et al. (2004) as Prionospio sp. G is likely to be Prionospio vallensis. It was reported as the most abundant macrofaunal species at 3514 m and 4141 m. Prionospio vallensis sp. nov. was the single most abundant polychaete in Portuguese canyons, achieving densities of 784 ind./m 2 in Set��bal canyon (3400 m) and up to 918 ind./m 2 in Nazar�� canyon (3400 m) (Cunha et al. 2011; Paterson et al. 2011). The difference in the abundance between our study and previous ones may be a reflection of different sampling design used during RRS Discovery cruise 186, where macrofauna was sieved on 300 -micron mesh. However, it was not present in Portuguese canyon samples collected at 1000 m or on the Tagus Abyssal Plain, which is adjacent to Set��bal and Cascais canyons. It is possible that this is a deep canyon ���specialist��� able to utilize the organically enriched sediments found within the canyon (compared to similar noncanyon depths) and/or rapidly occupy sediments following frequent disturbances, which occur within canyons. Data from previous studies in these canyons (Gage et al. 1995; Curdia et al. 2004) suggest that P. vall ensis sp. nov. has been able to maintain high-density populations in Portuguese canyons on more than a decadal timescale (sampling in 1989, 1999, 2005, 2006). Distribution. Nazar��, Set��bal, and Cascais canyons along the Portuguese margin, 3199���4419 m., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 8-11, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Aurospio Maciolek, 1981 a, Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on page 19, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Prionospio Iberian Canyons sp. C (Figures 2.7, 9) Material examined: 23 specimens examined. Voucher specimens: Portuguese margin Nazar�� canyon : St. 15765 # 2 39 ��35.00���N 10 �� 19.04 ���W, 4336 m; 5 individuals. Other material examined: Nazar�� canyon: RSS Discovery 2005, St. 15758 # 2 39 �� 34.94 ���N 10 ��19.00���W, 4332m, 8 individuals; St. 15758 # 6 39 �� 34.99 ���N, 10 ��19.00���W 4335 m, 8 individuals; RSS Charles Darwin 179 April/ May 2006, St. 56847 # 7 39 �� 35.55 ���N 10 �� 20.06 ���W, 4404 m, 2 individuals. Diagnostic features. Eleven pairs apinnate branchiae, neuropodial hooded hooks and sabre chaetae not present in the first 31 chaetigers. Description. Voucher specimen incomplete with 31 segments, measuring 1.6 mm long (length to chaetiger 10) and 0.22mm wide (at chaetiger 1). Body wide and somewhat flattened; appears divided into two parts: branchial region plus four following segments with enlarged notopodial lamellae and dense capillaries and postbranchial region, with abruptly smaller notopodial lamellae and less dense capillaries. Colour pale yellow colour in alcohol. Prostomium nearly oval, with anterior margin somewhat truncated, prostomial peaks absent; distinct caruncle not formed, posterior margin of prostomium reaching to chaetiger 1 (Fig. 10 a); eyes not observed. Peristomium well developed, closely surrounding prostomium, ventrally distinct, dorsally incomplete; partially fused to chaetiger 1; lateral wings not formed. Palps missing. Eleven pairs of branchiae present on chaetigers 2���12; branchiae only slightly longer than accompanying notopodial lamellae, all of similar shape and size throughout, but with last two pairs shorter; all apinnate, but heavily ciliated on both sides, except for the tip; branchiae rather narrow but somewhat flattened���strap-like, wider at the base and tapering into somewhat swollen tip (Fig. 10 a,b). Notopodial postchaetal lamellae enlarged in branchial region (chaetigers 2���12) (Fig. 2.7 a���d), about three times longer than neuropodial postchaetal lamellae, reduced in size in chaetigers 13���16, then abruptly smaller from chaetiger 17 (Fig. 2.7 e), similar in size to neuropodial postchaetal lamellae; notopodial postchaetal lamellae subtriangular in branchial segments, becoming more small, oval, somewhat produced into blunt tip in postbranchial segments. No dorsal crests in 31 segments. Interparapodial pouches absent. Neuropodial postchaetal lamellae on chaetiger 2 small, oval with blunt distal tip; in other branchial segments enlarged, subquadrangular with produced tip dorsally; gradually becoming smaller and more oval assuming shape similar to the one on chaetiger 2 in postbranchial segments. Only capillary chaetae present in incomplete 31 chaetiger-long holotype. Capillaries long and dense in branchial region; straw-coloured, arranged in four rows: two rows of shorter and two rows of longer capillaries; capillaries in postbranchial segments less dense, arranged in single row. Neuropodial hooded hooks, sabre chaetae and notopodial hooded hooks absent in 31 segments. Pygidium unknown. Methyl green pattern: Prostomium and peristomium stain strongly, the margins of notopodial and neuropodial lamellae in branchial regions also stained, more intensively in anteriormost segments. Remarks. Given that in the voucher specimen all branchiae are apinnate, this species is similar to species grouped by many authors into Minuspio. Minuspio was erected by Foster (1971) to include all species with only apinnate branchiae. Maciolek (1985) in her revision of Prionospio suggested that Minuspio was only a sub-genus. Subsequent authors have been similarly divided in their designations and Minuspio has been used as a genus and subgenus. Many of the species designated to this taxon have more than four pairs of branchiae. Eleven pairs of branchiae are present on chaetigers 2���12 in the voucher of Prionospio spC, but branchiae are missing in all other specimens and their number may be variable. The absence of neuropodial sabre chaetae and neuropodial hooded hooks in 31 segments (the largest fragment) appears to be a unique feature of this species. In other species of Prionospio described to date, the neuropodial hooks usually start around segment 20 at the latest and sabre chaetae are usually present before this. However, given that the largest specimen available for examination was only 31 chaetigers long, it is possible that sabre chaetae/neuropodial hooks may start later in body. Given that no described species of Prionospio have the either neuropodial hooks or sabre chaetae starting so far back on the body, we consider that this is a distinct species but we are reluctant to formally classify it until we have more complete specimens. We therefore choose to describe but not name the species to enable future workers to identify it with the hope that complete specimens will be discovered and allow a more comprehensive description. Distribution. Nazar�� canyon (Portuguese margin) at 4364���4404 m., Published as part of Paterson, Gordon L. J., Neal, Lenka, Altamira, Iris, Soto, Eulogio H., Smith, Craig R., Menot, Lenaick, Billett, David S. M., Cunha, Marina R., Marchais-Laguionie, Claire & Glover, Adrian G., 2016, New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta) in Zootaxa 4092 (1) on pages 18-19, DOI: 10.11646/zootaxa.4092.1.1, http://zenodo.org/record/259914

Aurospio abranchiata sp. nov. Neal, Paterson & Soto (Figures 8 c, 10, 13, 14, Table 3) Prionospio sp B: Paterson et al., 2011 Material examined: 97 specimens examined in total. Holotype: Cascais canyon: RRS Charles Darwin, cruise 179, April–May 2006, St. 56823 # 2 2006.04.27, 38° 18.01 ’ N, 09° 47.02 ’ W, 3218 m, megacore (NHMUK 2015: 1043). Paratypes: Portuguese margin: Nazaré canyon RSS Discovery 297 August 2005, St. 15755 # 1 39 º 30.62 ’N, 09º 56.19 ’ W, 3461 m, 3 individuals; St. 15760 #1, 39º 30.02 ’ N, 09º 56.17 ’W 3465 m, 5 individuals; St. 15762 #1, 39º 30.02 ’ N, 09º 56.22 ’ W, 3464 m, 2 individuals; St. 15758 #6, 39º 34.99 ’ N, 10 º19.00’ W, 4335 m, 5 individuals; St. 15765 #2, 39º35.00’ N, 10 º 19.04 ’ W, 4336 m 4 individuals. RSS Charles Darwin cruise 179 April–May 2006, St. 56851 #1, 39° 29.99 ’ N, 09° 55.97 ’ W, 3517 m, 2 individuals; St. 56851 #2, 39° 29.99 ’ N, 09° 56.01 ’ W, 3517 m, 2 individuals. Setúbal canyon: RSS Charles Darwin cruise 179 April–May 2006, St. 56804 # 5 2006.04. 21 38 ° 09.27’N 09° 36.93 ’W 3275m 8 individuals; St. 56804 # 6 2006.04. 21 38 ° 09.26’N 09° 36.94 ’W 3275m, 10 individuals; St. 56806 # 1 2006.04. 21 38 ° 09.29’N 09° 36.96 ’W 3275m, 10 individuals; St. 56810 # 1 2006.04. 23 38 ° 09.22’N 09° 37.02 ’W 3224m, 1 individual; St. 56816 # 1 2006.04. 25 38 ° 09.27’N 09° 36.94 ’W 3275m, 14 individuals; St. 56842 # 1 2006.05.0 5 38 ° 06.45’N 09° 59.94 ’W 4482m, 2 individuals. Cascais canyon: RSS Charles Darwin cruise 179 April–May 2006, St. 56823 # 2 2006.04. 27 38 ° 18.01 ’N 09° 47.02 ’W 3218m, 9 individuals; St. 56828 # 1 18.02 ’N 09° 46.98 ’W 3199m, 1 individual. PA P: RRS Challenger II 79 May 1991: 52701 # 5 48 º51.0’N 16 º30.0’W, 4840 m, 1 individual. RRS Discovery D 222 September 1996: 12930 # 39 48 º 49.95 ’ N, 16 º 29.4 ’ W, 4840 m, 1 individual. RRS Discovery D 226 March 1998: 13077 #23, 48º 49.28 ’ N, 16 º 30.56 ’ W, 4844 m, 2 individuals. RRS Discovery D 229 July 1997: 13200 #20, 48º 49.8 ’ N, 16 º 29.62 ’ W, 4844 m, 2 individuals; 13200 # 47 48 º 39.29 ’ N, 16 º 30.27 ’ W, 4844 m, 1 individual. RRS Discovery D 231 March 1998: 13368 #36, 48º 49.78 ’ N, 16 º 30.17 ’ W, 4845 m, 2 individuals; 13368 #42, 48º 50.08 ’ N, 16 º 29.88 ’ W, 4844 m, 1 individual; 13368 #44, 48º 49.7 ’ N, 16 º 30.12 ’ W, 4844 m, 1 individual. Diagnostic features. Lack of branchiae, enlarged square-shaped notopodial lamellae on third segment; neuropodial lamellae largest on chaetiger 3 forming long, rectangular with rounded edges, wing-like structure which sometimes extends horizontally away from body. Description. Small and slender species, holotype incomplete with 45 segments, measuring 5.65 mm long for 45 segments and 0.2 mm wide (width at chaetiger 1). Colour in alcohol pale yellow. Body narrow and cylindrical, of uniform width throughout. Prostomium rounded, anterior margin entire, broadly rounded, prostomial peaks absent; short blunt caruncle, extending to anterior of chaetiger 1; eyes not observed. Peristomium well developed, ventrally and laterally distinct, dorsally partially fused to chaetiger 1, forming a collar around prostomium, without forming distinct lateral wings. Branchiae absent. Notopodial and neuropodial postchaetal lamellae reduced in chaetiger 1; notopodial lamellae on chaetiger 2 nearly square-shaped, meeting at midline and covering the dorsum in larger specimens but more widely separated in smaller ones (Fig. 11.2 a, 3 a); largest on chaetiger 3; lamellae large, nearly square, almost meeting at the midline, covering the entire dorsal surface of the segment in large specimens but not in smaller ones (Fig. 11.2 b, 3 b). Notopodial postchaetal lamellae on chaetigers 4–5 smaller, about half the size of those on chaetiger 3, changing from square to rounded shape from chaetiger 6 onwards, all well separated, not covering the dorsum (Fig 11.2 c, 2 d, 3 c, 3 d). Distinct dorsal crests from chaetiger 8–12. Interparapodial pouches absent. Neuropodial lamellae on chaetiger 2 square-shaped with rounded corners; on chaetiger 3 very large, rectangular with rounded edges (somewhat indented on outer rim), wing-like structure which sometimes extends horizontally away from body. The neuropodial postchaetal lamellae in other segments becoming more rounded and of similar size. Capillaries in two rows in both notopodia and neuropodia. Sabre chaetae present singly from chaetiger 10 in neuropodia; stout, strongly curved, no granulation. Neuropodial hooded hooks present from chaetiger 11–12, up to 4–5 par fascicle; at least five pairs of small teeth above the main fang; square-shaped primary hood, secondary hood present, rudimentary. Notopodial hooks present singly from chaetiger 38. Pygidium unknown. Methyl green pattern. Strong stain remains on sides of segments 5–17, even six months after staining. Remarks. The absence of branchiae together with the shape and size of both notopodial and neuropodial lamellae on third segment are diagnostic characteristics of this species. The absence of branchiae poses a difficulty in assigning this species to a genus with certainty. Within the Spionidae the genera Spiophanes Grube, 1860 and Spiogalea Aguirrezabalaga and Ceberio, 2005, are characterised by a lack of branchiae. However, the specimens described here do not belong to these genera because they lack modified, hook-like setae in the neuropodia of chaetiger 1, which are found in Spiophanes and the two chitinous plates surrounding the peristomium, which are characteristic of Spiogalea. The specimens also lack the characteristic arrangement of neuropodial chaetae found in the mid-chaetigers of Spiophanes described by Meißner & Hutchings (2003) and Meißner (2005). In overall appearance this species bears close resemblance to species belonging to the Prionospio complex. Our species does not seem to belong to either Paraprionospi o or Orthoprionospio based on the first segment having chaetae and the first chaetiger not being completely separated from peristomium usually found in Paraprionospi o and Orthoprionospio. The genus Streblospio can be eliminated because our specimens lack a ridge across chaetiger 1 and a prominent hood or collar across the dorsum of chaetiger 2; the form of the neuropodial multidentate hooks is also different. The problem of generic assignment arises when trying to determine whether the species belongs to the genus Aurospio or Prionospio. Aurospio was separated from Prionospio primarily on branchiae staring from third chaetiger, their shape, and that they are partially fused at their base to the notopodia. An additional character cited by Maciolek (1981) is the absence of a secondary hood in the hooks of Aurospio. Sigvaldadottir (1998) emphasised a lack of prostomial peaks, a short caruncle reaching to the anterior margin of chaetiger 1; pointed dorsal lamellae in mid-body segments, the absence of dorsal crests, and sabre chaetae starting on chaetiger 10 or earlier in her analyses of Prionospio. However, A. banyulensis (Laubier, 1966) and A. pilkensis (Wilson, 1990) do not have the branchiae fused to the base of the notopodia. Also, many species of Prionospio do not have secondary hoods in the neuropodial hooded hooks (Wilson 1990). Many of the characters highlighted by the cladistic analyses of Sigvaldadottir (1998) are actually also found in species of Prionospio. For example, short caruncles can be found in P. coorilla Wilson, 1990; P. pulchra Imajima, 1990; P. somaliensis Cognetti-Varriale, 1988; and P. vari gat a Imijima, 1990. Such overlap blurs the distinction between the genera and so we are left with the characters of the branchiae. Our species lacks these key characters. Thus it becomes difficult to place this new species into a genus. We do not believe that the absence of branchiae justifies erection of a new genus or subgenus within Prionospio –complex, but provides further support for view of Wilson (1990) and Sigvaldadottir (1998) that the differentiation of genera/subgenera based primarily on branchial arrangement is not justified. Therefore, based on the overall body shape, shape of the prostomium and shape of the dorsal lamellae, particularly the pair associated with chaetiger 3, this new species most closely resembles the characters displayed by species of Aurospio. Aurospio dibranchiata, A. foodbancsia Mincks et al., 2008, and A. banyulensis appear to have large rectangular-shaped dorsal lamellae on chaetiger three, often orientated towards the mid-line. By contrast the dorsal lamellae of chaetiger 3 in Prionospio are usually described as foliose or auricular and pointed with a rounded tip. A. pilkena is an exception to this rule, having been placed in Aurospio presumably because the branchiae start on chaetiger 3. However, such characters have not been completely assessed by comparison with all other species of Prionospio and the assignment to Aurospio is principally by the general impression of the specimens, in particular the rounded shape of the prostomium. This is not a satisfactory conclusion. A major review of the generic boundaries, using molecular as well as morphological characters, will be needed to resolve this problem. Etymology. abranchiata —refers to the absence of branchiae. Ecology. A. abranchiata sp. nov. was the second most abundant spionid species found in the canyons of the Iberian margin by the HERMES programme. However, it achieved higher densities in mid-depth canyons (around 3400 m) than in deep-water canyons with highest densities found in Cascais canyon, where it replaced P. vallensis sp. nov. as the most dominant spionid species. Cascais canyon is considered to be the most quiescent of the three canyons studied along the Portuguese margin. Cascais canyon also had the lowest abundance, but highest diversity and evenness, of polychaete assemblages. Aurospio abranchiata sp. nov. was also found in Setúbal canyon at 3400 m during RRS Discovery cruise 186 in 1989, where it was highly dominant, contributing nearly 30 % of the total polychaete abundance. The increased density during D 186 compared with densities recorded during the HERMES program is difficult to interpret as different mesh-sized sieves were used. A. abranchiata sp. nov. is a very slender species and larger numbers could have been caught in the 0.3 -mm mesh used during D 186 than in 0.5 -mm and 1 - mm mesh used during the HERMES sampling program. The species is also quite numerous in the sediment samples from the Porcupine Abyssal Plain where it reaches abundances of 40 individuals per metre 2. The absence of branchiae provides an interesting insight into evolutionary adaptations in these deep-sea spionids. The deep-sea species of Aurospio — A.dibranchiata, A.foodbancsia, and A. abranchiata sp. nov. show a reduction both in the size of branchiae and also in the number. A. dibranchiata has two pairs of small branchiae, A. foodbancsia has one pair while A. abranchiata sp. nov. has no branchiae. The absence of branchiae in A. abranchiata sp. nov. could be compensated by extremely large notopodial lamellae, which are also a diagnostic feature of this species. Distribution. Porcupine Abyssal Plain at 4800 m, Nazaré, Setúbal and Cascais canyons along Portuguese margin at 3199–4485 m.

Prionospio amarsupiata sp. nov. Neal & Altamira (Figures 1, 2.1, 3, 8e) Prionospio sp D Paterson et al. 2011: 2453. Material examined. 24 specimens examined. Holotype: Setúbal canyon RRS Charles Darwin 179. April–May 2006, St. 56842 #1, 38º06.45’N 9 º 59.94 ’W, 4482 m (NHMUK 2015: 1042). Paratypes: Portuguese margin canyons: Nazaré canyon RRS Discovery 297, August 2005, St. 15758 #2, 39º 34.94 ’ N 10 º19.00’ W, 4332 m, 2 individuals; St. 15765 #2, 39º35.00’ N, 10 º 19.04 ’ W, 4336 m, 1 individual. RRS Charles Darwin 179, April–May 2006, St. 56861 # 1 39 º 35.57 ’ N, 10 º 20.02 ’ W, 4404 m, 1 individual. St. 56847 # 6 39 ° 35.57 ’N 10 ° 19.99 ’W 4403m, 1 individual. Setúbal canyon RRS Charles Darwin 179. April–May 2006, St. 56804 #5, 38º09.27’N 9 º 36.93 ’W, 3275m, 1 individual; St. 56804 # 6 38 º09.26’N 9 º 36.94 ’W, 3275m, 3 individuals; St. 56806 #1, 38º09.29’N 9 º 36.96 ’W, 3275m, 1 individual; St. 56838 # 2 38 º06.50’N 9 º 59.98 ’W, 4482m, 1 individual; St. 56842 #1, 38º06.45’ºN 9 º 59.94 ’W, 4482m, 3 individuals; Cascais canyon RRS Charles Darwin 179. April–May 2006, St. 56837 #8, 38º 22.49 ’N 9 º 53.52 ºW, 4244 m, 1 individual; St. 56821 #1, 38º 17.96 ’N 9 º 46.87 ’ºW, 3219m, 1 individual; St. 56823 #2, 38º 18.01 ’N 9 º 47.02 ’ºW, 3218m, 1 individual; St. 56828 #1, 38º 18.02 ’N 9 º 46.98 ’W, 3199m, 1 individual. Other material studied: Crozet Island RRS Discovery D 300, December 2005 – January 2006, site M6,15773#31, 49°01.92’S 51 ° 13.88 ’E, 4192 m, 1 individual. Site M5, 15773#18, 45° 52.96 ’ S, 56 ° 23.78 ’ E, 4186 m, 1 individual. Kaplan CCFZ Central Site (IFREMER Nodinaut campaign): RV L’Atalante, May–June 2004 KAP 3, CRS 868 / MTB9, 14° 3.093 ’N, 130 ° 4.7825 ’W, 5031m, individual KP397, 1 individual. EqPac: RV Thomas Thompson, November 1992, BC15, 5°N 140 W, 0-1cm, EP 436 1 individual Madeira Abyssal Plain: RRS Discovery, August 1990, 12174 3-5cm, 300 µm: (MAST_Polychaete Intercalibration Project number–map 55), 1 individual. Cape Verde Abyssal Plain: RRS Discovery, October 1993, 12600 # 10 213.2 ’N 3111.0’W, 4543 m, MAST_cv7, 1 individual. Diagnostic features. Lack of interparapodial pouches, first branchial pair with only few pinnules at the base of branchiae. Description. Holotype incomplete with 42 segments, measuring 14.5 mm long for 42 chaetigers and 0.63 mm wide at chaetiger 1. Pale yellow colour in alcohol. Prostomium angular, bottle-shaped with broadly rounded anterior margin, prostomial peaks normally absent (but two small peaks observed in one of the CROZET specimens); slender caruncle extending to anterior margin of chaetiger 2 (Fig. 3 a); eyes not observed. Peristomium well developed, encircling prostomium closely like a collar, partially fused to chaetiger 1, forming low lateral wings (Fig 3.a). Four pairs of branchiae present on chaetigers 2–5. First pair longest, reaching to chaetiger 10, very slender and cylindrical, although slightly flattened near base and with slender, slightly curled tips; surface mostly smooth to slightly wrinkled (Fig. 2.1 a); very few (1–3) pinnules near base; fourth pair of branchiae similar to first pair but about half the length, apinnate, no rudimentary pinnules observed. Branchial pairs 2 and 3 short, fleshy, foliaceous, wider at base, tapering into somewhat swollen tip, laterally ciliated, both pairs slightly shorter than accompanying notopodial lamellae, in dorsal view both pairs covered by enlarged notopodial lamellae. All branchial pairs situated lateral and slightly posterior to notopodial lamellae. Anterior notopodial lamellae from chaetiger 2–20 (holotype) generally enlarged, subtriangular, largest on branchial segments, particularly on chaetigers 3 and 4; more narrow on chaetiger 5; from chaetiger 6 increasing in width, becoming nearly square by chaetiger 10; after chaetiger 20 greatly reduced in size, becoming flattened assuming broadly ovoid shape with sharp pointed dorsal end and broad round posterior ventral end (Fig. 2.1 e chaetiger 22). Dorsal crests on chaetigers 5–20. Neuropodial lamellae small on chaetiger 1, largest on branchial chaetigers, then gradually becoming reduced in size; lamellae on chaetiger 2 fan-shaped with rounded corners (Fig 2.1 a); lamellae on chaetiger 3 also fan-like possesing well developed ventral tip (Fig. 2.1 b); lamellae on chaetiger 4 rounded; lamellae on cheatiger 5 low, rectangular (Fig. 2.1 c); from chaetiger 6 more rounded ventrally, starting to assume broadly ovoid in shape with somewhat pointed ventral tip (Fig. 2 e–f); similarly shaped through chaetiger 42, with lamellae becoming more flattened and pointed both dorsally and ventrally (Fig. 2.1 f). Interparapodial pouches absent (Fig. 3 b). Notopodia in anterior region with four rows of dense, yellow-hued capillaries, anterior neuropodial capillaries arranged in two rows. Sabre chaetae and neuropodial hooks start on chaetiger 19 in holotype and other specimens of similar size, but on chaetiger 18 in smaller specimens. Sabre chaetae long, slender, gently curved, often broken; anterior half is lightly granulated; 1 to 2 per fascicle. Neuropodial hooks up to 10 per fascicle. Neuropodial hooks long, slender, with round, inflated primary hood and striated secondary hood; shaft very constricted just below multidentate head, with six pairs of small teeth above the main fang (Fig. 3 c,d). Notopodial hooks not present in 42 chaetigers. Pygidium unknown. Methyl green pattern. Prostomium, peristomium and the edge of notopodial and neuropodial lamellae on chaetiger 1–4 stained strongly, thereafter only edges of notopodial lamellae and dorsal crest with faint stain. Remarks. This species closely resembles Prionospio ehlersi Fauvel, 1928 in the shape of the prostomium and peristomium and the chaetiger where the sabre chaetae and neuropodial hooks appear; neuropodial hooded hooks and sabre chaetae begin on chaetigers 18–19 in P. amarsupiata sp. nov., which is within the range of their occurrence on chaetigers 18–22 in P. ehlersi. The major difference is in the small number of pinnules on first branchial pair and lack of pouches in Prionospio amarsupiata sp. nov. This feature has been encountered in specimens collected from Crozet as well as in Portuguese canyons, EqPac and PAP specimens. It seems likely, therefore, that reduction in number of pinnules is a real feature of this species rather than a loss of pinnules, damaged during the handling of the specimens Interestingly, a species identified as Prionospio cf. ehlersi but lacking pouches was reported by Blake (1983) from the deep sea in the Antarctic and Chile. In a later publication Blake (1996) concluded that: “…these widely scattered deep-sea records of a P. ehlersi -like species that lack interparapodial pouches represent at least one, yet undescribed species.” It is likely that at least some of Blake’s specimens are P. amarsupiata sp. nov. In additional deep-sea material examined, Blake encountered a specimen that lacked pouches but had a full branchial set (first pair short and pinnate, pairs 2, 3, and 4 short, all the same length, thick, and apinnate). This particular specimen is clearly different from P. amarsupiata sp. nov. based on its branchial form. Some specimens collected from HERMES canyons were reproductive with eggs, the largest of which were approximately 70 microns in diameter. Etymology. amarsupiata, meaning “lacking pouches”; from the Latin marsupium, a pouch; reference is to the lack of interparapodial pouches in this species. Distribution. This species is widespread in the deep sea; confirmed records indicate the species has been recorded from the Nazaré, Setúbal and Cascais canyons along the Portuguese margin (3199–4488 m), Crozet Island (3500 m), the Equatorial Pacific (EqPac), and the Northeast Atlantic (Cape Verde Abyssal Plain 4500 m, Madeira Abyssal Plain 4800 m).

Aurospio tribranchiata sp. nov. Paterson & Soto (Figure 1, 8 d, 10, 11, 12, Table 3) Minuspio sp 4 Soto 2008: 89. Material examined: 33 specimens examined in total. Holotype: Porcupine Abyssal Plain, RRS Discovery D 229, July 1997, 13200 #20, 48º 49.8 ’ N, 16 º 29.62 ’ W, 4844 m, 1–3 cm, 0.3 mm (NHMUK 2015: 1199). Paratypes: Porcupine Abyssal Plain, RRS Challenger 79, May 1991, 52701#9, 48º 51.6 ’ N, 16 º 27.4 ’ W, 4842 m, 2 individual; 52701 #25, 48º 50.4 ’ N, 16 º 29.6 ’ W, 4844 m, 3 individuals; 52701 #47, 48º 50.6 ’ N, 16 º 29.9 ’ W 4841 m, 1 individual. Porcupine Abyssal Plain, RRS Discovery D 222, August 1996, 12930#14, 48º 50.92 ’N, 16 º 30.24 ’W, 4837 m, 1 individual; 12930 # 44, 4849.95 ’N, 1630.2 ’W, 4839 m, 1 individual; 12930 # 59, 4850.45 ’N, 1630.58 ’W, 4837 m, 1 individual; 12930 #68, 48º 49.92 ’N, 16 º 29.76 ’W, 4840 m, 2 individual; 12930 #73, 48º 50.08 ’N, 16 º 29.69 ’W 4839 m, 2 individuals. 1) Aurospio tribranchiata sp. nov. a) Chaetiger 2; b) Chaetiger 3; c) Chaetiger 4; d) Chaetiger 5; scale bar = 100 µm. 2) Aurospio abranchiata sp. nov. from PAP a) Chaetiger 2; b) Chaetiger 3; c) Chaetiger 4; d) Chaetiger 5; e) Chaetiger 8; scale bar = 100 µm. 3) Aurospio abranchiata sp. nov. from canyons a) Chaetiger 2; b) Chaetiger 3; c) Chaetiger 4; Chaetiger 5; scale bar = µm. Porcupine Abyssal Plain, RRS Discovery D 226, March 1998, 13077#19, 4850’N, 1630.05 ’W, 4846 m, 4 individual; 13077 # 23, 4849.28 ’N, 1630.56 ’W, 4844 m, 1 individual; 13077 #59, 48 49.98 N, 16 29.96 W, 4845 m, 1 individual; 13078 #13, 48º50.00’N, 16 º30.0’W, 4843 m, 1 individual. Porcupine Abyssal Plain, RRS Discovery D 229, July 1997, 13200 # 17, 4849.67 ’N, 1628.72 ’W, 4843 m, 2 individuals; 13200 #20, 48º 49.8 ’ N, 16 º 29.62 ’ W, 4844 m, 3 individuals; 13200 # 47, 4839.29 ’N, 1630.27 ’W, 4844 m, 1 individual; 13200 #52, 48º 49.84 ’N, 16 º 29.84 ’W, 4844 m, 2 individuals. Porcupine Abyssal Plain, RRS Discovery D 231, March 1998, 48 50.51 ’N 16 29.43 ’W, 4842 m, 1 individual; 13368 #25, 48º 50.51 ’N, 16 º 29.43 ’W, 3 individuals. Porcupine Abyssal Plain, RRS Discovery D 237 September 1998, 13627# 17, 4849.9 ’N, 16 49.9 ’W, 4837 m 2 individuals. Diagnostic features: three pairs of branchiae, first pair starting on chaetiger 3 and the last pair being much longer than the other two. Description. Small slender species with thorax widening posteriorly then staying the same width; holotype fragment with 20 chaetigers, 3.00 mm long; 0.18 mm wide at chaetiger 1 (not including the chaetae). Colour cream to pale yellow. Prostomium rounded to rectangular; caruncle long extending to anterior edge of chaetiger 2, well developed, then appearing to extend weakly beyond segment boundary. No eyes. Peristomium separated ventrally and laterally from chaetiger 1, fused dorsally forming a distinct rounded collar. Palps simple up to 5 chaetigers in length, no basal sheath. Branchiae present on chaetigers 3 to 5; all apinnate, cylindrical, tapering gradually to a rounded point; branchiae on chaetigers 3 and 4 short, about the same length as the accompanying dorsal lamellae; branchiae on chaetiger 5 long, up to five chaetigers in length and two to three times the length of the accompanying dorsal lamellae (Fig. 11.1 d; 12 a,c, 13 a,c. Chaetiger 1 with small rounded notopodial lamellae. Notopodial lamellae increase in size with the largest on chaetigers 4 and 5; lamellae triangular on chaetigers 2 and 3, becoming wider and more rounded on chaetigers 5 and 6. Notopodial lamellae in mid-body low and rounded. Dorsal crests low difficult to see but occur on chaetigers 9 to 12. Neuropodial lamellae on chaetiger 1 small rounded, increasing over chaetigers 2 to 9; lamellae largest on chaetiger 3 (Fig 12 b). Capillaries arranged on two rows on notopodia and neuropodia, capillaries bilimbate with those in the lower row slightly granulated. Sabre chaetae robust, curved, limbate, slightly or non-granulated, starting on chaetiger 10 or 11; one per fascicle. Neuropodia hooded hooks start on chaetiger 12, up to six per fascicle; two to three pairs of small teeth above the main fang (specimens small difficult to see the exact arrangement), no inner hood; Notopodial hooded hooks not observed. Pygidium unknown. Methyl green pattern. Band of stain across middle of prostomium or across whole prostomium, diffuse over body. Remarks. A. tribranchiata sp. nov. is assigned to Aurospio because the branchiae start on chaetiger 3. All specimens of A. tribranchiata, were carefully examined stained with Shirlastain A (SDL international. A textile fibre identification stain - very useful in revealing features, such as scars) and were not able to detect the presence of scars on any of our specimens. As further supporting evidence there was no branchial pair on chaetiger 2 or evidence of their scars even on otherwise complete specimens which had very long branchiae of chaetiger 4 (which could be easily lost) and palps (almost always lost in spionids) still attached. Based on current evidence we have assigned this species to Aurospio until proven otherwise. Other characters such as the shape of the prostomium, lack of an internal secondary hood in the hooded hooks also are common to species in this genus (but see Remarks in the previous species for a discussion on the problems of defining this genus). A. tribranchiata sp. nov. is similar to A. pilkena Wilson, 1990 and A. banyulensis (Laubier, 1963), in particular the form of the prostomium, having three pairs of branchiae (see Table 4). A. banyulensis also has dorsal crests starting on chaetiger 8, hooded hooks starting on chaetiger 12 and sabre chaetae on chaetiger 10. A. tribranchiata sp. nov. differs in the arrangement of the third pair branchiae which are long whereas on A. pilkena and A. banyulensis they are all the same size. A. longibranchiata differs from A. pilkena in the starting positions of the sabre chaetae and hooded hooks and having dorsal crests (see Table 4). Etymology. tribranchiata refers to the three pairs of branchiae found on this species. Ecology. A. tribranchiata sp. nov. is one of the dominant species of spionids found on the Porcupine Abyssal Plain, found in densities of between 4 and 24 individuals per m 2. This species was found within the sediment at depths between 0–5 cm. Distribution. This species has only been recorded from the Porcupine Abyssal Plain 48 °N, 16 ° W (Northeast Atlantic Ocean) and from a depth of 4800 m.

The number of records of the genus Prionospio Malmgren, 1867, from the deep sea (> 2000 m) are relatively few and do not reflect the actual occurrence of species nor their potential ecological importance. In this paper we describe five new species of this genus (Prionospio amarsupiata sp. nov., P. vallensis sp. nov., P. branchilucida sp. nov., P. hermesia sp. nov. and P. kaplani sp. nov.) all of which are abundant members of the deep-sea community. We also describe two new species of the genus Aurospio Maciolek, 1981 (Aurospio abranchiata sp. nov. and A. tribranchiata sp. nov.) again common elements of the abyssal fauna. Two of the new species have characters which question the generic distinctiveness of Prionospio and Aurospio. The problems in differentiating these two genera are discussed.

Amphioplus hexabrachiatus St��hr, 2003 (Figs. 9���10) Material examined. Mercator MV, TTR 15, stn AT 576, 4 inds. (DBUA 001084.01); Fiuza MV, TTR 14, stn AT 566, 2 inds. (DBUA 001085.01); Kidd MV, TTR 14, stn AT 559, 2 inds. (DBUA 001085.02); Yuma MV, TTR 14, stn AT 524, 1 ind. (DBUA 001085.03); Darwin MV, TTR 16, stn AT 608, 1 ind. (DBUA 001086.01); Captain Arutyunov MV, MSM01-03, stn 195, 1 ind. (DBUA 0010.87.01); Pen Duick Escarpment, TTR 16, stn AT 600, 1 ind.. Remarks. This species is hexamerous, reproduces asexually by division, and reaches a maximum size of about 2.5 mm disk diameter. This is the first six-armed species of Amphioplus and the third species of the genus known from the deep North Atlantic. The specimens from the Gulf of Cadiz closely resemble the description and images given by St��hr (2003). This is obviously a morphologically variable species; in the range of body sizes observed in this study, key features such as the arrangement of the oral papillae and buccal scale are often not developed. It is only in the larger specimens (disk diameter> 2 mm) where the tentacle scales develop and are conspicuous. On the dorsal surface the development of the radial shields changes from small plates only separated at the inner edge to more elongated, larger plates separated nearly the full length of the plate only contiguous at the outer end. Smaller specimens show distinct evidence of fissiparity with one side of the disk being less well developed and smaller. Ecology and distribution. This species was described from southwest of Iceland at depths of 1000���1500 m, collected by the Benthic Invertebrates of Icelandic Waters (BIOICE) programme (St��hr 2003). In the Gulf of Cadiz (Fig. 7 E) it was collected from the Pen Duick Escarpment and mud volcanoes of the Moroccan margin usually in areas with carbonate crusts or coral framework at depths between 414 and 1390 m extending the upper bathyal limit from 1000 to 414 m. The records from Cadiz also extend considerably the known geographical range of this species., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 18, DOI: 10.5281/zenodo.276727, {"references":["Stohr, S. (2003) A new fissiparous amphiurid brittlestar (Echinodermata: Ophiuroidea) from southwest of Iceland. Sarsia, 88, 373 - 378."]}

Ophiopristis gadensis sp. nov. (Figs. 3���5) Material examined. Holotype: NE Atlantic: Gulf of Cadiz, Captain Arutyunov MV, MSM01-03, stn 195, 1 ind. (NHM 2010.352 Holotype). Paratypes: same data as holotype, 12 inds. (DBUA 001147.01); 7 inds. (NHM 2010.353 - 359). Diagnosis. Ophiacanthid with sub-pentagonal disk; radial shields exposed, triangular in shape and less than a half disk radius in length; disk covered by thin plates; some plates bearing a spinelet; spinelets long, hollow with a smooth tip or 2���3 pointed spires. Oral surface covered with thin opaque skin in larger individuals but skin not obvious in smaller specimens; two apical papillae with 3 to 5 pointed oral papillae; second oral tentacle pore emerges superficially onto the oral surface, 3 to 5 rounded tentacle scales associated with pore; adoral shield separating oral shield from first lateral arm plate; oral shield triangular to sub-pentagonal. Arms distinctly noded at least 4 times disk diameter; plates become glassy on distal segments; dorsal arm plates triangular to scallop-shaped, proximally contiguous in large specimens, separated in smaller individuals; ventral arm plates rectangular with a convex distal edge; lateral arm plates with six arm spines; arm spines up to three arm segments long, dorsal arm spines finely rugose round to slightly flattened, ventral arm spines more obviously flattened with saw-like edge; proximal tentacle pores armed with two to three sub-equal tentacle scales, further out on the arm the scales reduce to two, one large leaf-like scale partially overlying a smaller scale. Holotype description. disk sub-pentagonal (d.d. 8.3 mm). Arms at least four times disk diameter. Disk covered with thin scales, many carrying a spinelet. Spinelets long, hollow, rugose, with tip of spinelet produced into a smooth point, sometimes with two or three small pointed spires; spinelets in middle of disk finer than those on the periphery or in the interbrachial region. Radial shields exposed, approximately triangular in shape; each shield pair separated along whole length; length extending slightly shorter than a quarter of the disk diameter. Ventral interbrachial area covered with small scales. Spinelets present but shorter and with a lower density than aboral surface. Oral surface covered by thin skin, partially obscuring the plate beneath. Jaws slightly longer than broad. Two apical papillae on most jaws. Up to five oral papillae along each jaw edge, papillae longer than wide with pointed tip; small pointed, distal papillae lie deeper within mouth. Second oral tentacle pore emerging superficially onto the surface of the jaw. Oral tentacle scales larger than oral papillae, four to five in number, often longer than high with a rounded free edge; tentacles scales superficial situated on oral surface and separated from oral papillae. Adoral shields large, slightly wider at their junction with the arm plates and separating oral shields from first lateral arm plate. Oral shields rounded pentagonal slightly longer than broad. Arms long, distinctly noded in proximal segments, arm plates becoming glassy. Disk plates extending onto proximal arm segments nearly surrounding first dorsal arm plate. Dorsal arm plates triangular to scallop-shaped with convex distal edge; plates contiguous at least on proximal segments; on distal segments dorsal arm plates more triangular and just contiguous. Ventral arm plates approximately rectangular with a convex distal edge, contiguous on proximal arm segments. Tentacle pores covered, on the proximal segments oval scales, slightly pointed and often of different sizes; each pore with three scales arranged around the first two to four arm pores, decreasing to two thereafter until nearly the end of the arm; two scales comprised of a large glassy, slightly pointed, almost leaf-like scale sitting over a smaller inner scale. Lateral arm plates flared forming a ridge along the area where arm spines inserted. Arm spines six, up to three arm segments in length on proximal arm segments becoming shorter on distal ones; not quite forming a continuous row on the first free arm segment. Dorsalmost spines finely rugose, slightly flattened; ventralmost spines shorter, wider at the base of the spine, much flatter developing a saw-like edge with distinct teeth, terminating in triple-tipped spine; tip of arm spine glassy. These ventralmost spines become shorter on outer arm segments forming a row of large teeth along the ventral edge on the outer part of the arm spine. Variation (Paratypes). Large individuals conform to the description of the holotype. Smaller individuals, d.d. 3.5 to 6 mm, do not have thickened skin over the oral surface so the plates are clearer. Oral shields are more rounded slightly wider than long. Jaws with three to four oral papillae which are slightly more rugose than in larger specimens. However in other characters, such as tentacle scale number and arrangement, smaller specimens resemble the larger, although the gap between the oral papillae and oral tentacle scales is more obvious. Oral shields triangular slightly more elongated and rounded. Dorsal arm plates on smaller specimens are triangular with a convex distal edge and are separated, not contiguous. Often just two tentacle scales The number of scales may be the result of a larger scale being split perhaps during development thus resulting in three scales not two. Distribution and ecology. This species is only known from the type locality. It was collected from a coral thicket (Dendrophylia cf. alternata, mostly dead branches with a few living polyps) at a single station on the flanks of Captain Arutyunov MV at a depth of 1390 m, together with Ophiactis abyssicola, Ophiacantha aristata and Amphioplus hexabrachiatus. Etymology. This species is named after the area (Gulf of Cadiz) where it was first discovered; Gades is the old Roman name for Cadiz. Remarks. Placing this species within Ophiopristis Verrill, 1899 represents a compromise and potentially expands the definition of the genus. There are a number of characters which appear to be unique. The emergent radial shields are unusual in the Ophiotominae and in Ophiopristis, the arrangement of the oral papillae and second oral tentacle scales are also distinct and finally the development of thickened integument has not been reported within species of the genus. However, such variation in the degree of skin covering the disk has also been noted for other ophiacanthids, for example Ophiolebes scorteus Lyman, 1878, without resorting to the erection of a new genus. It is possible that this combination of characters within this species represents a new genus, however as Paterson (1985) and O���Hara and St��hr (2006) point out, the genera within Ophiacanthidae are not well defined and so adding another would only serve to add to this problem. Ophiopristis gadensis sp. nov. share the following features with other species of the genus - the arm spines are slightly flattened with a rugose edge, the oral and second tentacle papillae are separated either physically or by shape and size, the tentacle scales are multiple in proximal arm segments. Ophiopristis can now be defined as: jaws longer than broad, flanked on each side by four or more oral papillae, second oral tentacle pore superficial opening near the surface of the jaw, armed with tentacle scales similar in size and shape to the oral papillae, sometimes confluent with oral papillae but in some separated; adoral shields long and narrow, separating the oral shield from the first lateral arm plate; disk covered with small scales carrying an elongated spinelet, often long, hollow and with pointed or furcate tips; radial shield usually concealed but maybe exposed; arm spines flattened, carrying a row of sharp points along each edge; tentacle pores armed with up to four tentacle scales on proximal first two to four pores decreasing to one to two large scales on segments thereafter. According to St��hr and O���Hara (2007) there are eight species of Ophiopristis. O. gadensis sp. nov. differs in the type of disk spines which are more rugose and not smooth as in most of the other species; the presence in larger specimens of the thickened integument and the distinct separation between the oral papillae and the second oral tentacle scales. Ophiopristis gadensis sp. nov. is similar to O. dissidens Koehler, 1905 in having three tentacle scales on proximal tentacle pores but differs in that the disk spinelets are not smooth, glassy and hollow. A comparison of the species is given in Table 2., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on pages 8-11, DOI: 10.5281/zenodo.276727, {"references":["Verrill, A. E. (1899) Report on the Ophiuroidea collected by the Bahama expedition in 1893. American Journal of Science, 28, 213 - 220.","Lyman, T. (1878) Ophiuroidea and Astrophytidae of the exploring voyage of the HMS Challenger I. Bulletin of the Museum of Comparative Zoology, 5 (7), 65 - 168.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","O'Hara, T. D. & Stohr, S. (2006) Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In Richer de Forge, B & Justine, J. - L. (eds), Tropical Deep Sea Benthos, 24, 33 - 141.","Koehler, R. (1905) Ophiures de l'expedition du Siboga. 2 e. Partie: Ophiures littorales. Siboga Expeditie Monograph, 45 (b), 1 - 142."]}

Amphiura filiformis (O.F. M��ller, 1776) Material examined. Al Idrisi MV, TTR 12, stn AT 412, 2 ind. (DBUA 001071.01); Mercator MV, TTR 15, stn AT 569, 10 inds. (DBUA 001072.01); stn AT 575, 18 inds. (DBUA 001072.02); stn AT 576, 17 inds. (DBUA 001072.03); MSM01-03, stn 237, 2 inds. (DBUA 001073.01); stn 241, 37 inds. (DBUA 001073.02); stn 242, 24 inds. (DBUA 001073.03); stn 267, 2 inds. (DBUA 001073.04); stn 287, 3 inds. (DBUA 001073.05); Fiuza MV, TTR 14, stn AT 566, 5 inds.; West of Gibraltar Strait, TTR 14, stn AT 552, 1 ind. (DBUA 001074.02); Pen Duick Escarpment, TTR 12, stn AT 407, 1 ind. (DBUA 001071.02); TTR 16, stn AT 602, 1 ind. (DBUA 001075.01). Ecology and distribution. Amphiura filiformis is a common, predominantly shallow-water species of the north-Eastern Atlantic. It is known to occur from Norway to West Africa and also in the Mediterranean Sea at depths up to 1665 m (Paterson 1985). This species is often found sympatric with A. chiajei. Both species live buried in fine muddy sand but, unlike its congener, A. filiformis feeds in the water current extending its arms vertically 3���4 cm above the sediment surface (Vopel et al. 2003). In the Gulf of Cadiz A. filiformis co-occurred with A. chiajei in Mercator MV (Fig. 7 B). The highest density of A. filiformis (72���144 ind.m - 2) occurs in the crater where only one specimen of A. chiajei was collected; the latter reaches densities of 60 ind.m - 2 on the flank where the density of A. filiformis drops to 68 ind.m - 2. Amphiura filiformis has also a much wider distribution and has been recorded in two other mud volcanoes (Al Idrisi and F��uza) and in association with carbonate chimneys and crusts at two other sites (West of Gibraltar and Pen Duick Escarpment) at depths between 230 and 556 m., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 16, DOI: 10.5281/zenodo.276727, {"references":["Muller, O. F. (1776) Zoologiae danicae prodromus. Havniae. 282 pp.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Vopel, K., Thistle, D. & Rosenberg, R. (2003) Effect of the Brittle Star Amphiura filiformis (Amphiuridae, Echinodermata) on Oxygen Flux into the Sediment. Limnology and Oceanography, 48 (5), 2034 - 2045."]}

Amphilepis ingolfiana Mortensen, 1933 Material examined. Mercator MV, TTR 15, stn AT 569, 1 ind. (DBUA 001088.01), stn AT 575, 4 inds. (DBUA 001088.02), stn AT 576, 5 inds. (DBUA 001088.03); MSM01-03, stn 237, 1 ind. (DBUA 001089.01); Fiuza MV, TTR 12, stn AT 403, 1 inds.; Kidd MV, TTR 14, stn AT 559, 2 inds. (DBUA 001091.01); Yuma MV, TTR 16, stn AT 605, 1 ind. (DBUA 001092.01); Pen Duick Escarpment, TTR 12, stn AT 406, 1 ind. (DBUA 001090.01); TTR 16, stn AT 602, 1 ind. (DBUA 001092.02). Ecology and distribution. Amphilepis ingolfiana is a deep-sea species (957���4829 m) known to occur in the NE Atlantic from the Rockall Trough south to off North Africa (Paterson 1985). In the Gulf of Cadiz it was collected at the Moroccan margin in four mud volcanoes and in the Pen Duick Escarpment, often associated with carbonate crusts and at shallower depths (353���975 m) than previously reported (Fig. 7 F)., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on pages 18-19, DOI: 10.5281/zenodo.276727, {"references":["Mortensen, T. (1933) Ophiuroidea. Danish Ingolf Expedition, 4 (8), 121 pp.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162."]}

Amphiura chiajei Forbes, 1843 Material examined. Mercator MV, TTR 15, stn AT 569, 1 ind. (DBUA 001069.01), stn AT 576, 15 inds. (DBUA 001069.02), stn AT 577, 2 inds. (DBUA 001069.03); Kidd MV, TTR 14, stn AT 560, 1 ind. (DBUA 001070.01). Ecology and distribution. Amphiura chiajei has been recorded from the Eastern Atlantic and Mediterranean, and from West Africa; it is usually a shelf species but has been recorded from a depth of 1200 m (Paterson 1985). This species is reported as living buried in muddy sand, extending its arms above the surface of the sediments to feed on deposited material. In the Gulf of Cadiz it was collected from soft mud breccia in the crater of Mercator and Kidd mud volcanoes within its known bathymetric range (Fig. 7 A)., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on pages 14-15, DOI: 10.5281/zenodo.276727, {"references":["Forbes, E. (1843) On the Radiata of the eastern Mediterranean. Part 1. Ophiuridae. Transactions of the Linnean Society of London, 19, 143 - 153.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162."]}

Amphipholis squamata (Delle Chiaje, 1828) (Fig. 8) Material examined. Mercator MV, TTR 15, stn AT 568, 1 ind. (DBUA 001080.07); stn AT 575, 10 inds (DBUA 001080.01), stn AT 576, 5 inds. (DBUA 001080.02), stn AT 577, 2 inds. (DBUA 001080.03); MSM01-03, stn 241, 18 inds. (DBUA 001081.01), stn 242, 9 inds. (DBUA 001081.02), stn 287, 1 ind.; Fiuza MV, TTR 14, stn AT 566, 2 inds. (DBUA 001079.01); Kidd MV, TTR 14, stn AT 528, 2 inds.; stn AT 559, 2 ind. (DBUA 001079.02), stn AT 560, 9 inds. (DBUA 001079.03), stn AT 561, 3 inds. (DBUA 001079.04); TTR MV, TTR 12, stn AT 416, 16 inds. (DBUA 001082.01); Mekn��s MV, TTR 14, stn AT 541, 1 ind.; TTR 15, stn AT 581, 1 ind. (DBUA 001080.04), stn AT 585, 1 ind. (DBUA 001080.05), stn AT 587, 1 ind. (DBUA 001080.06); MSM01-03, stn 321, 7 inds. (DBUA 001081.03), stn 335, 15 inds. (DBUA 001081.04); Yuma MV, TTR 16, stn AT 604, 4 inds. (DBUA 001083.01); Ginsburg MV, TTR 16, stn AT 607, 3 inds. (DBUA 001083.02); Jesus Baraza MV, TTR 12, stn AT 391, 1 ind. (DBUA 001082.02); Darwin MV, TTR 16, stn AT 608, 8 inds. (DBUA 001083.03); Captain Arutyunov MV, TTR 12, stn AT 399, 2 ind. (DBUA 001082.03); MSM01-03, stn 212, 1 ind. (DBUA 001081.05), stn 194, 2 inds. (DBUA 001081.06), stn 225, 4 inds. (DBUA 001081.07), stn 274, 4 inds. (DBUA 001081.08), stn 344, 2 ind. (DBUA 001081.09); Formosa Ridge, TTR 12, stn AT 388, 2 ind. (DBUA 001082.04), stn AT 389, 5 inds. (DBUA 001082.05); West of Gilbratar Strait, TTR 14, stn AT 550, 3 inds. (DBUA 001079.05), stn AT 552, 24 inds. (DBUA 001079.06); Pen Duick Escarpment, TTR 12, stn AT 406, 18 inds. (DBUA 001082.06); TTR 14, stn AT 565, 1 ind. (DBUA 001079.07); TTR 16, stn AT 600, 8 inds. (DBUA 001083.04), stn AT 602, 4 inds. (DBUA 001083.05). Ecology and distribution. Amphipholis squamata is known from several substrata (under stones, amongst algal and bryozoan turfs, rockpool weeds and occasionally on sandy bottoms) from the intertidal to 1200 m. Current distribution records suggests that it is abundant in the Eastern Atlantic from Iceland along the European margin, Mediterranean Sea, West coast of Africa, West and East coast of South Africa and Madagascar (Alva & Vadon 1989). The taxonomy of this species is currently being investigated (S. St��hr, per comm.). It is likely that this presumed cosmopolitan species will turn out to be a complex of cryptic species and that there will need to be a revision of its geographic distribution. This species can switch from deposit feeding by collecting particles within its tube feet to suspension feeding via trapping detritus in mucus. In the Gulf of Cadiz it was the most common ophiuroid, recorded from 10 mud volcanoes and at three other sites in association to carbonate chimneys and crusts as well as cold-water corals (Fig. 7 D). Young, intermediate and adult stages were found together at the same localities. This species was found at depths from 350 to 1379 m which is its deepest known record., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on pages 16-17, DOI: 10.5281/zenodo.276727, {"references":["Delle Chiaje, S. (1828) Memoire sulla storia e notomia degli animali senza vertebre del regno di Napoli. Napoli: Societa Tipographica, 3, 1 - 232.","Alva, V. & Vadon, C. (1989) Ophiuroids from the western coast of Africa (Namibia and Guinea-Bissau). Scientia Marina, 53 (4), 827 - 845."]}

Ophiactis balli (Thompson, 1840) Material examined. Al Idrisi MV, TTR 12, stn AT 412, 2 ind. (DBUA 001065.01); West of Gibraltar Strait, TTR 14, stn AT 550, 1 ind. (DBUA 001066.01). Ecology and distribution. This is an Eastern Atlantic species known from depths of 60���400 m (Paterson 1985), generally found in crevices or amongst sessile invertebrates with the body concealed and the arms extended out into the water. It is characteristic of exposed or moderately exposed rocky situations especially on limestone (Picton & Morrow 2007). In the Gulf of Cadiz it was collected within its known bathymetric range from limestones at the crater of Al Idrisi MV and from carbonate chimneys in an exposed site (high bottom currents) West of Gibraltar Strait., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 14, DOI: 10.5281/zenodo.276727, {"references":["Thompson, W. (1840) Contributions towards a knowledge of the Mollusca Nudibranchia and Mollusca Tunicata of Ireland with a description of some apparently new species of invertebrates. Annals and Magazine of Natural History, 5, 84 - 102.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Picton, B. E. & Morrow, C. C. (2007) Encyclopedia of Marine Life of Britain and Ireland. Available from: http: // www. habitas. org. uk / marinelife / species. asp? item = ZB 2680 (20 / 11 / 2008)"]}

Ophiomusium lymani Wyville Thomson, 1873 Material examined. Porto MV, MSM01-03, stn 167, 1 ind. (DBUA 001094.01). Ecology and distribution. Ophiomusium lymani is a bathyal and abyssal species with a wide distribution in the Atlantic and Indo-Pacific oceans (Alva & Vadon 1989). In the Atlantic it has been reported from SE Iceland south to Cap Blanc at depths ranging from 651 to 4829 m (Paterson 1985). The single record from the Gulf of Cadiz is within its known bathymetric range. Only one specimen was collected from Porto MV among the frenulate (Polychaeta: Siboglinidae) fields that cover the crater., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 20, DOI: 10.5281/zenodo.276727, {"references":["Thompson, C. Wyville (1873) The Depths of the Sea. Macmillan & Co. London, 527 pp.","Alva, V. & Vadon, C. (1989) Ophiuroids from the western coast of Africa (Namibia and Guinea-Bissau). Scientia Marina, 53 (4), 827 - 845.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162."]}

Amphiura sp. A Stöhr and Segonzac, 2005 Amphiura sp. Stöhr and Segonzac 2005: 396 –397, figure 8 Material examined. Kidd MV, TTR 14, stn AT 528, 6 inds. (DBUA 001077.01); stn AT 560, 3 ind. (DBUA 001077.02); Meknès MV, TTR 14 stn AT 541, 9 inds. (DBUA 001077.03); Yuma MV, TTR 16, stn AT 604, 1 ind. (DBUA 001078.01); Darwin MV, TTR 16, stn AT 608, 1 ind. (DBUA 001078.02); Captain Arutyunov MV, TTR 14, stn AT 546, 3 inds. (DBUA 001077.04); West of Gibraltar Strait, TTR 14, stn AT 551, 1 ind. (DBUA 001077.05); Pen Duick Escarpment, TTR 16, stn AT 600, 1 ind. (DBUA 001078.03). Remarks. This species, herein designated as Amphiura sp. A, closely resembles the description given by Stöhr and Segonzac (2005) from West Atlantic cold seeps. The species is characterised by, having two tentacle scales on each arm tentacle pore and a scale-like distal oral scale, ten with a more spike-like scale situated on the adoral shields and just three arm spines, a character shared with other Amphiura species, the middle arm spine of the three is swollen. We have not formally classified this species because Amphiura species with three arm spines are common within the family (approximately 28 species). To formally name this species would require a major taxonomic review which is beyond the scope of the present work. Ecology and distribution. Amphiura sp. A as described by Stöhr & Segonzac was previously known from mud sediments among chemosynthetic fauna (Bathymodiolus boomerang, Escarpia sp.) of the Orinoco cold seeps, West Atlantic, at 1947 m. In the Gulf of Cadiz it has a wide distribution in the shallow and western areas of the Moroccan margin (carbonate provinces) predominantly associated to the presence of carbonate crusts and covering a bathymetric range of. 489–1345 m (Fig. 7 C). It was recorded from five mud volcanoes and two other sites with carbonate chimneys or crusts, often co-occurring with Amphipholis squamata and occasionally with other Amphiuridae (Amphioplus hexabrachiatus, Amphiura filiformis and Amphiura grandisquama).

Amphiura sp. A St��hr and Segonzac, 2005 Amphiura sp. St��hr and Segonzac 2005: 396 ���397, figure 8 Material examined. Kidd MV, TTR 14, stn AT 528, 6 inds. (DBUA 001077.01); stn AT 560, 3 ind. (DBUA 001077.02); Mekn��s MV, TTR 14 stn AT 541, 9 inds. (DBUA 001077.03); Yuma MV, TTR 16, stn AT 604, 1 ind. (DBUA 001078.01); Darwin MV, TTR 16, stn AT 608, 1 ind. (DBUA 001078.02); Captain Arutyunov MV, TTR 14, stn AT 546, 3 inds. (DBUA 001077.04); West of Gibraltar Strait, TTR 14, stn AT 551, 1 ind. (DBUA 001077.05); Pen Duick Escarpment, TTR 16, stn AT 600, 1 ind. (DBUA 001078.03). Remarks. This species, herein designated as Amphiura sp. A, closely resembles the description given by St��hr and Segonzac (2005) from West Atlantic cold seeps. The species is characterised by, having two tentacle scales on each arm tentacle pore and a scale-like distal oral scale, ten with a more spike-like scale situated on the adoral shields and just three arm spines, a character shared with other Amphiura species, the middle arm spine of the three is swollen. We have not formally classified this species because Amphiura species with three arm spines are common within the family (approximately 28 species). To formally name this species would require a major taxonomic review which is beyond the scope of the present work. Ecology and distribution. Amphiura sp. A as described by St��hr & Segonzac was previously known from mud sediments among chemosynthetic fauna (Bathymodiolus boomerang, Escarpia sp.) of the Orinoco cold seeps, West Atlantic, at 1947 m. In the Gulf of Cadiz it has a wide distribution in the shallow and western areas of the Moroccan margin (carbonate provinces) predominantly associated to the presence of carbonate crusts and covering a bathymetric range of. 489���1345 m (Fig. 7 C). It was recorded from five mud volcanoes and two other sites with carbonate chimneys or crusts, often co-occurring with Amphipholis squamata and occasionally with other Amphiuridae (Amphioplus hexabrachiatus, Amphiura filiformis and Amphiura grandisquama)., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 16, DOI: 10.5281/zenodo.276727, {"references":["Stohr, S. & Segonzac, M. (2005) Deep-sea ophiuroids (Echinodermata) from reducing and non-reducing environments in the North Atlantic Ocean. Journal of the Marine Biological Association of the United Kingdom, 85, 383 - 402."]}

Ophiactis abyssicola (M. Sars, 1861) (Fig. 6) Material examined. Captain Arutyunov MV, MSM01-03, stn 195, 3 inds. (DBUA 001064.01). Ecology and distribution. This is an Atlantic species known from a wide bathymetric range (125���4721 m) from Norway to southern Africa (Paterson 1985). In the Gulf of Cadiz it was collected from a coral thicket (Dendrophylia cf. alternata, mostly dead branches with a few living polyps) in a single station at the flanks of Captain Arutyunov MV (1390 m) together with Ophiopristis gadensis sp. nov., Ophiacantha aristata and Amphioplus hexabrachiatus., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 11, DOI: 10.5281/zenodo.276727, {"references":["Sars, M. (1861) Oversigt of Norges Echinoderm. Christiania. 160 pp.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162."]}

Ophiacantha aristata Koehler 1896 (Fig. 2) Material examined. Captain Arutyunov MV, MSM01-03, stn 195, 1 ind. (DBUA 001063.01). Ecology and distribution. This is a bathyal North Atlantic species (822���1700 m) known from SW Ireland south to the Canary Islands (Paterson 1985). In the Gulf of Cadiz it was collected from a coral thicket (Dendrophylia cf. alternata, mostly dead branches with a few living polyps) at a single station at the flanks of Captain Arutyunov MV (1390 m) together with Ophiopristis gadensis sp. nov., Ophiactis abyssicola and Amphioplus hexabrachiatus., Published as part of Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew & Cunha, Marina R., 2011, Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic), pp. 1-26 in Zootaxa 2754 on page 7, DOI: 10.5281/zenodo.276727, {"references":["Koehler, R. (1896) Resultats scientifiques de la compagne du Caudan dans le Golfe de Gascogne. Echinodermes. Annales de l'Universite de Lyon, 26, 33 - 122.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162."]}

Rodrigues, Clara F., Paterson, Gordon L. J., Cabrinovic, Andrew, Cunha, Marina R. (2011): Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic). Zootaxa 2754: 1-26, DOI: 10.5281/zenodo.276727