“Invasion” in the Russian Arctic: is global Climate Change a real driver? A remarkable case of two nudibranch species

In present paper, we report the first findings of two large and conspicuous nudibranch species for Russian waters - Goniodoris nodosa and Flabellina pellucida . Both species show wide distribution in the northeastern Atlantic waters or even in the northwestern Atlantic in the case of F. pellucida. The morphology of both species was studied using anatomical dissections and scanning electron microscopy. Molecular diversity was assessed by sequencing of COI marker and reconstruction of haplotype networks. In the Barents Sea, both species show minor genetic differences from their European relatives and similar morphological characters. Putative explanations of new findings for Russian Arctic are discussed.