深海最深处原生生物主导的硬底质动物群繁盛

Protist- dominated hard substrate faunas thrive at the deepest ocean depths The deepest hard- substrate fauna In situ images and specimens recovered from >9000- m depth in the Kermadec and Mariana trenches revealed 32 sessile species, mainly protists, most of them new to science (Fig. 1, fig. S2, and table S1). The larger fauna included Galatheanthemum profundale (13), another pre- viously unidentified sea anemone, a carnivorous sponge, and a polychaete. The most unexpected components, however, were four new and much smaller (millimeter- scale) species that occurred in high densities and dominated the hard- substrate Kermadec Trench assemblages. Three of these species were protists (Rhizaria): Gromia hadalensis sp. nov. (fig. S3A, fig. S4 and movie S2), Plumetta cernua gen. et sp. …