| Summary: | During the Census of Marine Life expeditions M79/1 DIVA-3 (Diversity of the abyssal Atlantic benthos) and ANDEEP 3 (Antarctic benthic DEEP-sea biodiversity), autonomous baited trap systems were employed to sample the mobile, necrophagous organisms at abyssal depths. Within DIVA-3 (2009), a free-fall baited trap was used successfully at three stations in the southwest Atlantic, once in the Argentine Basin and twice in the Brazilian Basin. A total of 21 stations were sampled by baited traps during the ANDEEP 1-3 (2002, 2005) cruises in the Southern Ocean. Trapsets recovered large numbers of mobile, scavenging lysianassids, in particular: Abyssorchomene abyssorum (Stebbing, 1888), A. chevreuxi (Stebbing, 1906), A. distinctus (Birstein & Vinogradov, 1960); Orchomene gerulicorbis (Shulenberger & Barnard, 1976); O. sp near gerulicorbis and 3 new Abyssorchomene species. Molecular analysis combined with a detailed, morphological study of the new material as well as the redescription of the type-specimens of A. abyssorum, A. chevreuxi (type-species), and A. musculosus has allowed the assessment of the status of Abyssorchomene among the orchomenid group of genera. The diagnosis, composition and affinities of the genus Abyssorchomene De Broyer, 1984 has also been revised due to the results of the study. The occurrence of at least one Abyssorchomene (new) sp. in both the Weddell Sea abyssal Basin and the Argentine Basin (but not in the Brazilian Basin) supports the connectivity between the Antarctic and south-west Atlantic abyssal basins.
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