Review of Arctic and Pacific Marenzelleria (Annelida: Spionidae), with new records and comments on Spio gorbunovi Averincev, 1990

Abstract

Here we summarise and map available records of the spionid polychaetes Marenzelleria spp. from the Arctic and Pacific Oceans based on morphology and analysis of sequences of five gene fragments (COI, 16S, 18S, 28S and Histone 3). We define for the first time the complex of M. arctia species, including M. arctia-1 from the Baltic, Barents and White Seas, and M. arctia-2 from the Kara Sea east to the Bering Strait. The relationships of these groups to M. arctia (Chamberlin, 1920) from the type locality of this species in the Beaufort Sea remain unclear. We report a new record of M. neglecta Sikorski and Bick, 2004 from Oregon, USA, and consider the presence of this species in the Canadian Arctic and USA Pacific due to introductions for which routes and vectors remain unclear. We also report M. wireni Augener, 1913 for the first time from Arctic Canada (Nunavut). Molecular analysis showed a genetic similarity of the Canadian specimens with worms identified as M. wireni from the Greenland and Laptev Seas. We expect that a future phylogenetic analysis of the relationships of the Asian population, which is currently referred to M. arctia and has never been studied genetically, will shed light on the origin and evolution of the entire genus. Study of the type specimens of Spio gorbunovi Averincev, 1990, described from the Laptev Sea, revealed that this species is a junior synonym of M. arctia, rather than M. wireni as proposed by previous authors.