The first Arctic conspicuously coloured Pleusymtes (Crustacea: Amphipoda: Pleustidae) associated with sea anemones in the Barents Sea

Abstract

The article presents a potentially obligate association of a pleustid amphipod of the genus Pleusymtes (Crustacea: Amphipoda: Pleustidae) with the large sea anemone Urticina eques (Gosse, 1858) (Anthozoa: Actiniaria: Actiniidae) from shallow waters of the Barents Sea. The new species shows a conspicuously striped (disruptive or aposematic) colouration, unlike other Arctic species of the genus, which shows a potential for its permanent connection with anemones. It is possible that this is the first known possibly obligatory anemone-associated species, within the genus and the family Pleustidae. The article discusses the taxonomy, morphological differences from congeners and ecological features of the new species, as well as the known symbiotic associations of sea anemones (as hosts) in Arctic and sub-Arctic waters.