Galapagomystides kathyae n. sp.

Figures 17, 18

Diagnosis. First segment fused dorsally to prostomium. Wider prostomium. Elongated dorsal cirri on segments 1, 2 and 3. Elongated ventral cirri on segment 2.

Material Examined. Holotype: SIO-BIC A13418 * (prepared for SEM), White Lady vent, North Fiji Basin, Fiji, 16.9905° S 173.9147° E, ~ 1990 m depth, June 1, 2005, ROV Jason II. [GenBank COI= MZ 711261] Paratypes: SIO-BIC A13422, A13423, A13424, A4651, A4645, White Lady vent, North Fiji Basin, Fiji, ~ 1990 m depth; A4587, Tow Cam, Lau Back-arc Basin, Tonga, ~ 2720 m depth. For locality details see Table 1. * indicates sequenced specimens .

Description. Holotype body length 14 mm long, 1 mm wide at segment 10 for ~65 segments. Body deep pink in life (Fig. 17C). Body brown/orange with numerous dark pigmentation speckles in preserved (formalin/ethanol) state (Fig. 17A, B, D). Lobe-like prostomium; nuchal organs not visible (Fig. 18A). Anterior dorsal edge of prostomium with paired cylindrical antennae ~ 0.2 mm long (Fig. 18A, D). Paired palps ventral to antennae, similar in shape and length to antennae (Fig. 18D). Segment one dorsally fused to prostomium, following segments clearly demarcated (Fig. 18A). Pair of elongated dorsal cirri [tentacular cirri] on each of segments 1 (~ 0.25 mm long), 2 (~ 0.25 mm long) and 3 (~ 0.2 mm long) (Fig. 18A). All elongated dorsal cirri cirriform, tapering distally. Pair of elongated ventral cirri on segment 2 ~ 0.15 mm long (Fig. 18D). Bulbous, rounded dorsal cirri ~ 0.08 mm long begin on segment 4 continuing posteriorly (Fig. 18A, C). Conical, tapering ventral cirri ~ 0.1 mm long begin on segment 3 continuing posteriorly (Fig. 18D). Ventral cilia bands present (Fig. 18D). Parapodia uniramous, notopodial chaetae absent; neuropodium with central fascicle containing ~5–8 compound chaetae; one simple emergent acicula (Figs 17E, F, G, 18F). Compound chaetal shaft cylindrical; thin, flattened pointed blade extended from curved joint (Fig. 17E). Pygidium with one pair of small lobed cirriform pygidial cirri ~ 0.1 mm long rounded distally (Fig. 18B).

Variation. Paratypes largely match the holotype. The paratype SIO-BIC A4651 of G. kathyae n. sp. is a juvenile (Fig. 17D), has less segments and is smaller than the holotype. This specimen was not sequenced but the morphology matches the holotype .

Remarks. Galapagomystides kathyae n. sp. is morphologically most like G. aristata and G. bobpearsoni n. sp. in having segment 1 dorsally fused to the prostomium. However, in the phylogenetic analyses, G. kathyae n. sp. was the sister group to G. verenae (Fig. 2). Galapagomystides kathyae n. sp. was found at both the North Fiji Basin and Lau Back-arc Basin, separated by 1110 km. The single specimen collected from the Lau Back-arc Basin does not have a DNA sequence but was morphologically like the holotype. The distinguishing morphological characteristics of G. kathyae n. sp. are a wide prostomium and elongated dorsal cirri originating from the second segment having a marked 90° angle distal to the body. The chaetal blades of G. kathyae n. sp. are thin and appear delicate, originating from a pointed joint.

Etymology. Galapagomystides kathyae n. sp. is named after the lead author’s mother, Kathy Reimer-Pearson, for her invaluable love and support, and who sparked the lead-author’s interest and enthrallment in invertebrates.