The near-bottom shrimp faunas (Decapoda: Natantia) at two abyssal sites in the Northeast Atlantic Ocean

Abstract

Bottom and near-bottom decapod shrimp communities from two northeast Atlantic abyssal sites (ca. 4 040 and 5 440m) were examined in 1984 and 1985. In both cases, an increase in abundance was observed in the bottom 90 m of the water column, with the largest numbers of shrimps occurring closest to the sediment surface (10 to 25 m off the bottom). The benthopelagic communities were composed of species drawn from both pelagic and benthic habitats rather than being specific and discrete. Hymenodora glacialis was the dominant species at the shallower site but it was absent from the near-bottom samples at the deeper one. H. acanthitelsonis, however, occurred at both sites. Several new depth records have been established, and there are two recordings of species previously unknown to the eastern Atlantic basin. Vertical migration and differences in modes of reproduction are discussed. © 1986 Springer-Verlag.