Neogyptis hinehina, Pleijel & Rouse & Sundkvist & Nygren, 2012

Pleijel, Fredrik, Rouse, Greg W., Sundkvist, Tobias & Nygren, Arne, 2012, A partial revision of Gyptis (Gyptini, Ophiodrominae, Hesionidae, Aciculata, Annelida), with descriptions of a new tribe, a new genus and five new species, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 165 (3), pp. 471-494 : 485-486

NEOGYPTIS HINEHINA SP. NOV. ( FIGS 9 , 10 )

Type material: Holotype ( SIO-BIC A2491 ). c. 70 paratypes ( SIO-BIC 2492–2495 ).

Type locality: Off Fiji, Lau Basin, 22°31.94′S, 176°43.11′W, 1821 m, RV Melville, ROV Jason, II dive J2-145, on vent site Hine Hina .

cal electron-dense nucleus capped by a simple acrosome and the midpiece is simple with a few mitochondria surrounding the anchoring apparatus. The flagellum consists of the axoneme and plasma membrane only.

Habitat: Sand and coarse sand at 1–30 m depth.

Distribution: Only known from Carrie Bow Cay and surroundings in Belize.

Remarks: Neogyptis fauchaldi sp. nov., shares brownblack eye colour with N. rosea comb. nov., N. hongkongensis sp. nov., and N. vostokensis comb. nov. It differs from N. rosea comb. nov. in having ten, rather than 35–80, papillae terminally on the proboscis, from N. hongkongensis sp. nov. in lacking lip pads but having curved notochaetae with conical side subdistally serrated, and from N. vostokensis comb. nov. in having slimmer ventral cirri with well-demarcated tips.

Etymology: Named after Hine Hina, the type locality.

Material examined: Holotype ( SIO-BIC A2491 , fixed in formaldehyde), off Fiji, Lau Basin , 22°31.94′S, 176°43.11′W, 1821 m, RV Melville, ROV Jason II dive J2-145, on vent site Hine Hina, 22.v.2005; c. 70 paratypes ( SIO-BIC A2492 , fixed in formaldehyde), same collection data as holotype; five spms (preserved in 95% ethanol, destroyed for DNA sequencing), same collection; five paratypes ( SIO-BIC A2493 , preserved in 95% ethanol), same collection data; three paratypes ( SIO-BIC A2494 , fixed in formaldehyde), off Fiji, Lau Basin, 22°32.33′S, 176°43.07′W, 1845 m, RV Melville, ROV Jason II dive J2-146, on vent site Hine Hina, 23.v.2005; five specimens ( FP collection, fixed in osmium and mounted on SEM stubs), same collection data; three paratypes ( SIO-BIC A2495 , fixed in formaldehyde), off Fiji, Fiji Basin, 16°59.43′S, 173°54.95′W, 1973 m, RV Melville, ROV Jason II dive J2-150, on vent site White Lady, 29.v.2005.

Description: Length up to 4.5 mm for 27 segments. Live animals opaque with yellow gut, red dorsal blood vessel distinct. Body outline elongated elliptical with tapering posterior end ( Fig. 9 ). Prostomium rounded, as wide as long ( Fig. 10A ). Palpophores cylindrical, palpostyles evenly tapering to rounded tips; palpostyles longer than palpophores ( Fig. 10A–C ). Paired antennae thinner and slightly shorter than palps, distal-most third forming well-demarcated tips. Median antenna similar in shape to paired antennae but shorter, inserted on anterior third of prostomium ( Fig. 10A, B ). Eyes absent. Nuchal organs short ciliated bands along lateral sides of prostomium ( Fig. 10B ). Lip pads absent. Proboscis opening with terminal ring of ten elongated papillae ( Fig. 10C ). Non-everted proboscis reaching segment 8. Segment 1 dorsally reduced, segment 2 fully developed. Dorsal cirri and cirrophores segment 1–5 much longer and stouter than following ones; longest dorsal cirri reaching segment 11–12. Ventral cirri segment 1–3 with well-delineated cirrophores and longer and stouter cirri than on following segments ( Fig. 10C ). Segment 4 and 5 with neuropodial lobes, neurochaetae and ventral cirri similar to following segments, segment 6 with notopodial lobes and notochaetae. Dorsal cirri thin ( Fig. 10D ), reaching about as far as or slightly further than chaetae. Dorsal cirri alternation uncertain. Transverse dorsal ridges across median and posterior segments ( Fig. 10D ). Notopodial aciculary lobes conical. Notochaetae of three kinds: one to four bent aciculary chaetae, large number of capillary chaetae with alternating rows of teeth, and few, ventrally positioned curved chaetae with conical side subdistally serrated. Neuropodial lobes conical. Neurochaetal blades of three kinds: with prolonged teeth, with smooth long blades positioned medially in bundle, and with short serration. Notochaetae except aciculary chaetae and shaft of neurochaetae twisted along longitudinal axis. One to three notoaciculae and usually two neuroaciculae, one smaller and one larger. Ventral cirri tapering to fine points ( Fig. 10E ). Pygidial cirri similar to dorsal cirri; pygidial papilla absent ( Fig. 10F ).

Habitat: Hydrothermal vents, 1821–1973 m.

Distribution: Only known from the hydrothermal vent sites Hine Hina and the White Lady in the Lau Basin off Fiji.

Remarks: Neogyptis hinehina sp. nov. is unique within Amphidurini in lacking eyes, in having neurochaetae from segment 4, and in having twisted noto- and neurochaetae.

Figures

Figure 9. Neogyptis hinehina sp. nov., dorsal view of live relaxed paratype (SIO-BIC A2492), 4.5 mm long.

Figure 10. Neogyptis hinehina sp. nov., scanning electron microscopy photographs of specimens from the type locality. A, anterior end, dorsal view. B, anterior end, left side. C, anterior end, ventral view. D, posterior segments with dorsal ridges, dorsal view. E, median parapodia, right side, ventral view. F, posterior end, posteroventral view. Scale bars: A, B, D, F = 100 Mm, C = 50 Mm, E = 200 Mm. Scale bars: A–C, E = 100 Mm, D = 300 Mm, F = 50 Mm.