Bathymetric distribution of Mysidacea in fjords of western Norway

Abstract

Depth distributions of 20 mysid species sampled between 32 and 1260 m are presented. A total of 113 sledge samples from 67 stations are evaluated. A change in the mysid fauna correlated to depth was found from the shallowest station and down to about 350 m. Below 350 m, fauna differences between fjords were greater than depth-related variations within fjords. Epibenthic species of Erythrops were found throughout the whole bathymetric range and of Pseudomma from 166 to 1260 m. Shallower than 100 m Schistomysis ornata and Leptomysis gracilis dominated by number, while deeper Boreomysis megalops and B. arctica dominated. Possible effects of the fjord sills on the fauna1 distribution are discussed. Bathymetric species groups containing all known mysid species from the studied area are proposed 0 to 50 m containing 13 species, 30 to 100 m containing 5 species, 100 to 350 m containing 5 species. > 250 m containing 9 species.