Galapagomystides patricki n. sp.

Figures 19, 20

Diagnosis. First segment not fused to prostomium. Elongated dorsal cirri on segments 1 and 2. No elongated ventral cirri.

Material Examined. Holotype: SIO-BIC A13419* (prepared for SEM), Parrita Seep, Costa Rica; 9.0303° N 84.623° W, ~ 1415 m depth, March 1, 2009, HOV Alvin. [Genbank COI= MZ 711314] Paratypes: SIO-BIC: A13425, A13426, A13427, A13420 *, A13421*, Parrita Seep, Costa Rica ~ 1400 m depth ; SIO-BIC: A9964 *, A9875*, A9877*, A9961*, A9934, Parrita Seep, Costa Rica ~ 850 m depth ; MZUCR 1510-01 *, Jacó Scar, Costa Rica, ~ 1770 m depth ; SIO-BIC: A1424, ~ 20 km away Parrita Seep, ~ 805 m depth . For locality details see Table 1. * indicates sequenced specimens.

Description. Holotype body length 16 mm, 1mm wide at segment 10 for ~70 segments. Body red or white with red gut in life (Fig. 19A). Body brown/orange with numerous dark pigmentation speckles in preserved (formalin/ ethanol) state (Fig. 19C, D). Lobe-like prostomium; nuchal organs not visible (Fig. 20A). Anterior dorsal edge of A A prostomium with paired cylindrical antennae (~ 0.25 mm long) (Fig. 20A). Paired palps ventral to antennae, similar in shape and length to antennae (Fig. 20A, D). Segment one not fused to prostomium, distinct dorsally and ventrally, following segments clearly demarcated (Fig. 20A, C). Pair of elongated dorsal cirri [tentacular cirri] on each of segments 1 (~ 0.4 mm long), 2 (~ 0.35 mm long) (Fig. 20A). All elongated dorsal cirri cirriform, tapering distally (Fig. 20A). Dorsal elongated cirri on segment one, right side and dorsal elongated cirri on segment two, left side were broken off the holotype. No elongated ventral cirri (Fig. 20D). Segment 3 lacking dorsal cirri (Figs 19B, C, 20A). Bulbous, rounded dorsal cirri (~ 0.1 mm long) begin on segment 4 continuing posteriorly (Fig. 20C). Ventral cirri absent on segment 1 (Fig. 20D). Bulbous ventral cirri (~ 0.1 mm long) (Fig. 20D). Chaetae begin on segment 2 continuing posteriorly (Fig. 20A). Parapodia uniramous, notopodial chaetae absent; neuropodium with central fascicle containing ~6–10 compound chaetae; one simple emergent acicula (Figs 19E, F, G, H, 20F). Compound chaetal shaft cylindrical; thin, flattened triangular short blade extending from rounded joint (Figs 19E, 20F). Pygidium with one pair of lobed pygidial cirri (~ 0.15 mm long) rounded distally (Fig. 20B).

Variation. Most G. patricki n. sp. type material specimens were within + /- 1 to 3 mm from the holotype in overall length, though one juvenile was ~ 10 mm smaller than the holotype. The specimens ranged from ~40 segments to ~70 segments. In life, the paratypes of G. patricki n. sp. had a body that was semi-translucent white/pink at parapodial lobes, dorsal and ventral cirri, prostomium and pygidium; red in the gut region center with a yellow patch on prostomium, elongated cirri and pygidial cirri (Fig. 19B).

Remarks. Most G. patricki n. sp. samples were collected from Parrita Seep, Costa Rica (1400 m), except for one specimen collected from the deeper Jacó Scar, Costa Rica (1800 m). A single sample, A1424, was collected from a multicore that was deployed offsite in the vicinity of the seep. Some G. patricki n. sp. specimens were found in sediment tubes inside empty vestimentiferan tubes. Morphologically, G. patricki n. sp. is most like G. verenae new comb. as both species show no fusion of anterior segments with the prostomium. However, in the phylogenetic analyses, G. patricki n. sp. was the sister group to the rest of the genus (Fig. 2). Galapagomystides patricki n. sp. lacks dorsal cirri on segment three (all other species have either elongated or regular dorsal cirri on segment three). The chaetae of G. patricki n. sp. had the shortest blades compared to other species and are also triangular (while the blades in other species are falcate).

Etymology: Galapagomystides patricki n. sp. is named after Patrick Shaughnessy, whose love and support during this project was instrumental to the lead author’s success.