COLONIAL ASCIDIA <i>DIDEMNUM VEXILLUM</i> KOTT, 2002 IS AN ALIEN SPECIES IN PETER THE GREAT BAY (THE SEA OF JAPAN)
In November 2013 in Vostok Bay (Peter the Great Bay, the Sea of Japan), in the fouling of experimental installation of the Mytilus trossulus mussel culture, the mass settlements of colonial ascidia not previously observed in Peter the Great Bay were registered. The taxonomic identification of colonial ascidia is rather complicated, and frequently the morphological and genetic methods of the species determination don’t give a clear result. The usage of molecular-phylogenetic methods allowed us to indicate the sequences of nucleotides obtained from 3 colonies of ascidia from the Vostok Bay as inherent to the invasive species Didemnum vexillum Kott, 2002. This species is known as an invader in aquaculture settlements of mussels and oysters in the various regions of the World Ocean in different years.