A new species of Regabellator Siebenaller & Hessler, 1981 (Isopoda, Asellota, Nannoniscidae) from the Amundsen Sea shelf (Southern Ocean)
Based on benthic material collected during the BIOPEARL (Biodiversity, Phylogeny, Evolution and Adaptive Radiation of Life in Antarctica) II expedition on board RRS “James Clark Ross” a new nannoniscid species,Regabellator brixorumsp. n., is described from the Pine Island Bay continental shelf, western Amundsen Sea (Antarctica). The new species most closely resemblesRegabellator armatus(Hansen, 1916) but can be distinguished from this species by possessing ventral spines on pereonites 1-4, the shape of the cephalothorax anterior margin and the length of the pereonite 7 ventral spine. The genusRegabellatorhas been previously recorded from the North and South-eastern Atlantic and here exclusively from the deep sea (1946 m and below). The new species represents the first record of the genusRegabellatorfrom the Antarctic continental shelf and thus greatly extends hitherto known latitudinal and bathymetric ranges for this genus.