Into the deep: diversity of valviferan isopods (Crustacea: Peracarida) from the Mar del Plata submarine canyon and adjacent area, Argentina

Abstract

The present study investigates the diversity of the deep-sea Valvifera from the Mar del Plata submarine canyon and adjacent area (MdPSC-AA), Southwest Atlantic. Forty-one benthic samples collected between 250 and 3282 m depth during the “Talud Continental I–III” expeditions were studied. Valviferan isopods were recovered from 34 of the 41 samples collected. A total of 25 valviferan species were identified, which were distributed among four families: Antarcturidae (19 spp.), Austrarcturellidae (4 spp.), Idoteidae (1 sp.), and Pseudidotheidae (1 sp.). Eight new species, eight new geographic records and 11 new bathymetric records are reported. The numberof species per haul was negatively associated with depth. Beta diversity showed a moderately high turnover of species across the depth gradient. The biogeographic analysis revealed that most of the species recorded from the MdPSC-AA were also reported from the slope of the Magellan Region (MR-slope). Novel associations between valviferan isopods and other invertebrates are documented.