First report of Hyssuridae (Isopoda: Anthuroidea) from Japan, with the description of a new Kupellonura species

We describe Kupellonura tamago sp. nov., collected from the North Pacific off the southern coast of the Boso Peninsula, Japan, at a depth of 445-407 m. This is the first record of Hyssuridae not only for Japan but also for the Temperate Northern Pacific ecoregion. Female K. tamago closely resembles Kupellonura gidgee Poore and Lew Ton, 1988 and Kupellonura indonesica Annisaqois and Wagele, 2021 in the shape of the uropodal exopod but differs from them in having a broader uropodal exopod (length/width ratio 1.47), a broader uropodal endopod (length/width ratio 1.64), and the telson margins smooth. We transfer Kupellonura flexibilis (Pasternak, 1982), originally described in Ananthura Barnard, 1925 but provisionally transferred to Kupellonura Barnard, 1925, to Anthelura Norman and Stebbing, 1886 in Antheluridae, as Anthelura flexibilis (Pasternak, 1982) comb. nov.