The Clarion-Clipperton Zone, central Pacific Ocean (purple box) is a 6 milllion km² region at the time of writing containing only 290 online-databased records of echinoderm species (OBIS 2015). The UK Seabed Resources Ltd ‘UK-1’ polymetallic nodule exploration claim area is highlighted (yellow box).

'UK-1 Stratum A' ABYSSLINE biological baseline survey box sited within the UK-1 polymetallic nodule exploration claim. Stratum A is a 30x30km survey box in the northern sector of the 58,000 km² claim area. Echinoderm sample localities are indicated by green circles from the AB01 RV Melville survey cruise, October 2013. Inset map A: the site location within the central Pacific, inset map B: all the echinoderm sampling locations (including site 'ROV7' to the west). Both inset maps use GEBCO 2014 bathymetry (global 30 arc-second interval grid data set). Seafloor bathymetry from the RV Melville ABYSSLINE cruise is shown in the main map.

ABYSSLINE UK-1 polymetallic nodule exploration claim field pipeline for DNA taxonomy. ABYSSLINE AB01 cruise sampling aboard RV Melville in October 2013. (a) Preparing Box Core (BC) for deployment, (b) BC entering the water, (c) Megacore entering the water, (d-f) Epibenthic Sledge shown on recovery in water and cod-end where samples are taken, (g) controlling BC deployment on seafloor, (h) echosounder trace showing BC approaching seabed reflection, (i) successful BC surface after recovery, 50cm x 50cm, (j) carefully sifting mud in chilled filtered seawater (approx. temp 5-7°C) to remove live animals in undamaged state, (k) live-sorting aboard ship, taking samples for DNA and photomicrographs of specimens down to <1mm in size. All images by Glover, Dahlgren & Wiklund. A more comprehensive description of our methods is provided in Glover et al. 2016.

Data and sample management workflow on the ABYSSLINE DNA taxonomy project. Processes relating to a) physical samples are shown in grey, b) institution level data in dark green and c) externally-available data in blue.

Phylogenetic analysis of the Asteroidea. 50% majority rule consensus tree from the Bayesian analyses, combining the three genes 18S, 16S and COI and using in total 60 taxa. Some of the clades are collapsed in order to make the tree smaller and easier to read.

Phylogenetic analysis of the Crinoidea. 50% majority rule consensus tree from the Bayesian analyses, combining the three genes 18S, 16S and COI and using in total 113 taxa. Some of the clades are collapsed in order to make the tree smaller and easier to read.

Phylogenetic analysis of the Holothuroidea. 50% majority rule consensus tree from the Bayesian analyses, using 16S and in total 115 taxa. Some of the clades are collapsed in order to make the tree smaller and easier to read.

Phylogenetic analysis of the Ophiuroidea. 50% majority rule consensus tree from the Bayesian analyses, combining the three genes 18S, 16S and COI and using in total 79 taxa. Some of the clades are collapsed in order to make the tree smaller and easier to read.

Asteroidea sp. Specimen NHM_054. (a) Dorsal. (b) Ventral. Scale bars (a,b) 2mm. Image attribution Glover, Dahlgren & Wiklund 2015.

Freyastera cf. benthophila Sladen, 1899. (a) Specimen NHM_413 (arm fragment) being recovered in situ from the seafloor during ROV dive RV06, (b) Additional, unsampled specimen, imaged during AB01 video survey and identified based on imagery as the same species, (c) Tentacle of specimen NHM_413 only part recovered; inset shows detail of tentacle. Scale bars (b) laser dots 242mm apart, (c) 20mm. Image attribution (a) Smith & Amon 2013, (c) Glover, Dahlgren & Wiklund 2015.

Porcellanaster cf. ceruleus Wyville Thomson, 1877 (a) Specimen NHM_267. (b) Detail of medial antenna. (c) Detail of tube feet. (d) Specimen NHM_253. Scale bars (a) 5mm, (b) 1mm, (c) 0.5mm. Image attribution Glover, Dahlgren & Wiklund 2015.

Styracaster paucispinus Ludwig, 1907. Specimen NHM_374 (a) Dorsal. (b) Detail of dorsal surface. (c) Ventral. (d) Ventral feet. Scale bars (a) 2mm, (b) 0.5mm, (c) 2mm. Image attribution Glover, Dahlgren & Wiklund 2015

Crinoidea sp. Specimen NHM_008. (a) Specimen attached to polymetallic nodule, live photograph, after recovery from box core. (b) Preserved specimen following DNA extraction. (c) Detail of crown, calyx and basals. Scale bars (a) 3mm, (b) 1mm, (c) 0.5mm. Image attribution Glover, Dahlgren & Wiklund 2015.

Crinoidea sp. Specimen NHM_055. (a) Specimen after removal from polymetallic nodule. (b) Detail of crown, calyx and arms as present after DNA extraction from 2 arms. Scale bars (a) 2mm, (b) 0.5mm. Image attribution Glover, Dahlgren & Wiklund 2015

Crinoidea sp. Specimen NHM_056. (a) Specimen after removal from polymetallic nodule. (b) Detail of crown, calyx, pinnules and arms as present after DNA extraction from stalk. Scale bars (a) 1mm, (b) 0.5mm. Image attribution Glover, Dahlgren & Wiklund 2015

Crinoidea sp. Specimen NHM_300 (a) Specimen found and imaged during shipboard live-sorting. (b) Detail of columnals (crown absent). Scale bars (a) 2mm, (b) 0.5mm. Image attribution Glover, Dahlgren & Wiklund 2015

Benthodytes cf. sanguinolenta Théel, 1882. Specimen NHM_216. (a) Specimen NHM_216 in situ on seafloor shortly before collection by ROV manipulator arm, (b) Live specimen photographed immediately after recovery from the ROV biobox, upper (dorsal view), lower (ventral view). Scale bar 5cm. Image attribution (a) Smith & Amon 2013, (b) Glover, Dahlgren & Wiklund, 2015.

Psychropotes cf. semperiana Théel, 1882. Specimen NHM_220. (a) Live specimen photographed in-situ on the seafloor. (b) Same specimen dorsal view after recovery by ROV imaged underwater in cold-water tank. (c) Ventral view. Scale bars (c) 10cm. Image attribution (a) Smith & Amon 2013, (b) Glover, Dahlgren & Wiklund, 2015.

Amphioplus cf. daleus Lyman, 1879. (a) Live specimen NHM_447 imaged dorsal side. (b). Dorsal surface detail. (c). Ventral surface detail. (d) Juvenile, confirmed by DNA data, NHM_094. Scale bars (a) 10mm. Image attribution Glover, Dahlgren & Wiklund, 2015.

Ophiomusium cf. glabrum Lütken and Mortensen, 1899. (a) Voucher material Specimen NHM_329 with insets showing detail of dorsal and ventral surface of disc. (b) NHM_124. (c) NHM_256. (d) NHM_338. (e) Unsampled specimens of suspected O. cf glabrum imaged during ROV surveys, showing 1 specimen on sediment surface and 1 specimen partially buried in sediment (green dot is a laser scale marker, cropped here). All voucher material specimens and designations confirmed with DNA data. Scale bars (a) 20mm, (g) 2mm. Image attribution (a-d) Glover, Dahlgren & Wiklund 2015 (e) Smith & Amon 2013.

Ophiotholia sp. specimen fragments, identified through DNA. (a) NHM_076. (b) NHM_076 detail. (c) NHM_104. (d) NHM_78. Scale bars (a) 300µm, (b) 200µm, (c) 500µm, (d) 1mm. Image attribution Glover, Dahlgren & Wiklund, 2015.

Ophiuroidea incertae sedis, specimen fragments, identified through DNA. (a) Ophiuroidea sp, NHM_072. (b) Ophiuroidea sp, NHM_041. (c) Ophiuroidea sp, NHM_303. (d) Ophiuroidea sp, NHM_371. Scale bars (b) 1mm, (c) 0.2mm. Image attribution Glover, Dahlgren & Wiklund, 2015.

Perlophiura profundissima Belyaev and Litvinova, 1972. Specimen NHM_257. (a) Live specimen imaged dorsal side. (b). Dorsal surface detail. (c). Ventral surface detail. Scale bars (a) 3mm, (b) 1mm. Image attribution Glover, Dahlgren & Wiklund, 2015.