Amphipod crustaceans were collected at all 55 stations sampled with an epibenthic sledge during two IceAGE expeditions (Icelandic marine Animals: Genetics and Ecology) in 2011 and 2013. In total, 34 amphipod families and three superfamilies were recorded in the samples. Distribution maps are presented for each taxon along with a summary of the regional taxonomy for the group. Statistical analyses based on presence/absence data revealed a pattern of family distributions that correlated with sampling depth. Clustering according to the geographic location of the stations (northernmost North Atlantic Sea and Arctic Ocean) can also be observed. IceAGE data for the Amphilochidae and Oedicerotidae were analysed on species level; in case of the Amphilochidae they were compared to the findings from a previous Icelandic benthic survey, BIOICE (Benthic Invertebrates of Icelandic waters), which also identified a high abundance of amphipod fauna.

Among the 125 currently recognized species of the panoceanic genus Leucothoe, L. antarctica was described in 1888 from the Antarctic seas, but was soon synonymized with the so-called cosmopolitan Leucothoe spinicarpa Abildgaard, which was cited from the Southern Ocean about 70 times since this first record. After erecting a new Antarctic species again only in 1983, “morphological variants” were observed and discussed. In this paper, we revalidate the first defined Antarctic species (Leucothoe antarctica), redescribe the second one (L. orkneyi), describe 5 new Southern Ocean species (L. campbelli sp. nov., L. longimembris sp. nov., L. macquariae sp. nov., L. merletta sp. nov. and L. weddellensis sp. nov.) and provide a key to all Antarctic and sub-Antarctic species.

The taxon Caprella acanthifera auct., usually considered to be one 'highly variable' species, is shown here to consist of a number of closely related species. In this paper three species of the group lacking an axillary spine near the insertion of gnathopod 2 are described and illustrated; the taxa with an axillary spine will be dealt with in a separate paper. This paper redefines Caprella acanthifera Leach 1814, sensu stricto; the nominal taxa C. hystrix, C. calva, C. aspera, and C. leptonyx are considered to be junior synonyms. Also described are C. stella sp.n., from starfish at the Azores and C. cavediniae sp.n., living among algae in the Mediterranean. The sources of apparent morphological variability in caprellids are discussed.

The Mediterranean amphipod species Dexamine filiola n. sp. and Ericthonius didymus n. sp. were discovered by their ovigerous females which differ in length from morphologically similar species. An error in the description of Stenothoe dollfusi Chevreux could finally be cleared up, and the Mediterranean material called Stenothoe gallensis Walker in reality belongs to Stenothoe cattai Stebbing.

This is the first part of a revision of the most plesiomorphic genera in the amphipod family Stenothoidae (see Krapp & Koenemann 2006). The genera Metopoides and Proboloides were both erected by Della Valle in 1893, and their species have hitherto often been confused and mixed. The present paper presents a cladistic analysis as well as a survey and partial redescription, where necessary, of all Metopoides species. – In a future second part the remaining genera of this basic stenothoid group (Proboloides, Torometopa, Scaphodactylus) will be similarly treated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)