Diversity and zoogeography of Icelandic deep-sea Ampeliscidae (Crustacea: Amphipoda)

International audienceA large collection of ampeliscids (15,454 specimens from 366 sampling sites) from Icelandic waters was identified to species and distributional patterns analysed. The specimens were sampled during the BIOICE programme, the main objective of which was to map the invertebrate species diversity within the Icelandic economical zone (758,000 km2). Nineteen species were identified: ten Ampelisca (8018 specimens), six Byblis (4887 specimens), three Haploops (1673 specimens), plus a complex of Haploops spp. (876 specimens). Four of these 19 species are new records for Icelandic waters: A. dalmatina Karaman, 1975 was previously known around the Faroe Islands; B. abyssi Sars, 1879 and B. affinis Sars, 1879 were known from the NE Atlantic and B. medialis Mills (1971) from the NW Atlantic. The three most abundant species were B. minuticornis Sars, 1879, B. gaimardi (Kr ¨ oyer, 1846) and A. uncinata Chevreux, 1887, while the three most frequently occurring species at all stations were H. setosa Boeck, 1871, A. uncinata and A. macrocephala Lilljeborg, 1852. Species were grouped according to three geographical patterns: northern species (six species), southern species (nine species) and circum-Icelandic species (four species). The species were also grouped according to three depth categories: nine species were confined to the continental shelf and the upper part of the continental slopes around Iceland; nine species had a wide bathymetric range and one species (A. islandica) occurred only in deep waters. Factors related to water depth exerted the main influence on ampeliscid distribution patterns around Iceland. A comparison of the Icelandic Ampeliscidae fauna with five areas of the North Atlantic Ocean showed a strong similarity to the fauna of Faroe Islands and a lesser similarity to the NW Atlantic fauna