Deep-sea asellota (Crustacea: Isopoda) of the rockall trough: Preliminary faunal analysis

Publisher Website
Google Scholar
Abstract
In 19 epibenthic sled samples, collected from 1973-1983 at one site in the southern Rockall Trough, NE Atlantic (54°40\s\N, 12°17.5\s\W) asellote isopods contributed 2-10% of the total fauna. Twelve families and 79 species were represented by 5318 individuals. The Ilyarachnidae, Haploniscidae, Ischnomesidae and Eurycopidae together provided 53 species and 77.21% of the collection (by numbers of individuals). None of the other families contributed more than 7%. The 35 most abundant species (less than halfthe total number) comprised 95% of the collection, while the least abundant 25 species together contributed only 1%. Indirect gradient analysis gave no indication of significant temporal change in the species composition of the site over the 11 year period, but one species of Ilyarachna gradually increased its percentage share ofthe collection from 3% in 1978 to 15% in 1981. No other significant temporal change was found. High inter-sample variability appears to be inherent in epibenthic sled sampling and is illustrated by contrasting the present results with previously published work. The importance of assessing the species richness of sites - and hence sampling efficiency - before carrying out comparative analyses is emphasised.