Two New Species of Vestimentiferan Tubeworm (Polychaeta: Siboglinidae a.k.a. Pogonophora) from the Brothers Caldera, Kermadec Arc, South Pacific Ocean

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Two new species of vestimentiferan tubeworm collected from the Brothers Caldera in the Kermadec Arc, South Pacific Ocean, are described here, based on morphological and molecular analyses, including sequence comparisons of over 600bp of the mitochondrial COI gene. Lamellibrachia juni sp. nov. differs from congeneric species in having flexible and thin-walled tubes, up to three pairs of lamellar sheaths, and similarly sized cuticular plaques on the vestimentum and trunk. Oasisia fujikurai sp. nov. differs from its sole congener in having eight pairs of branchial lamellae instead of up to 20. Oasisia and Ridgeia are shown likely to constitute a monophylum, but are retained as separate genera for now. The relationships between this clade and the genera Tevnia and Riftia remain unresolved. Within the monophyletic genus Lamellibrachia, L. juni sp. nov. is closest to L. sp. L7 from the Manus Basin.