New sponge species of the family Vulcanellidae (Demospongiae: Tetractinellida) from the Piip submarine volcano and adjacent areas (Bering Sea, NW Pacific)

Abstract

Four new species of vulcanellid sponges (Demospongiae: Tetractinellida), Poecillastra malyutini sp. nov., Vulcanella koltuni sp. nov., V. commander sp. nov. and V. grebelnyi sp. nov., are described from the Piip submarine volcano and adjacent area (the Bering Sea, North Pacific). This work includes materials sampled using the ROV Comanche 18 during the cruises of the RV Akademik M.A. Lavrentyev in 2016 and 2018. These specimens were studied and illustrated using light and electron (SEM) microscopy and micro-computed tomography (micro-CT). The distribution of species is characterized by pronounced vertical zoning. In areas of hydrothermal vents and on their periphery, Demospongiae are abundant with a pronounced dominance of a single species, V. koltuni sp. nov. The δ¹³C value for V. koltuni sp. nov. and P. malyutini sp. nov. from the volcano summits were almost 2-fold lower than for V. commander sp. nov. collected outside the areas of hydrothermal activity. These isotopic signatures indicate the organic matter of chemosynthetic origin in the diet of V. koltuni sp. nov. and P. malyutini sp. nov. Phylogenetic analysis based on 18S rDNA does not confirm the phylogenetic relationship of Lamellomorpha Bergquist, 1968 with the family Vulcanellidae Cárdenas, Xavier, Reveillaud, Schander & Rapp, 2011.