Description of a new species of Pseudobornella Baba, 1932 (Gastropoda, Nudibranchia, Dendronotidae) from the Yellow Sea

The genus <i>Pseudobornella</i> Baba, 1932 (Gastropoda, Nudibranchia, Dendronotidae), which was previously thought to be monotypic and restricted to the Western Pacific, is here expanded with the description of a second species, <i>Pseudobornellaqingdaoensis</i> <b>sp. nov.</b>, discovered in the Yellow Sea, China. The new species is similar in general body shape to its sole congener, <i>P.orientalis</i> Baba, 1932, but these species can be distinguished based on both external morphology and internal anatomy. Phylogenetic analyses reconstructed by Bayesian inference and maximum-likelihood methods using concatenated mitochondrial (COI, 16S rRNA) and nuclear (H3) genes and species delimitation analyses support the monophyly of <i>Pseudobornella</i> as well as the separation of the two known species.