Preliminary Studies of the Tardigrade Fauna of the Faroe Bank

Abstract

Four cruises to the Faroe Bank have collected bottom samples for qualitative analysis of the meiofauna. The preliminary results show a very rich tardigrade fauna, with a large proportion of species new to science. At present 35 species of tardigrades belonging to 4 families (6 sub-families) have been found, of these are 22 new to science (63%). The 35 species comprise more than 20% of all known marine tardigrades. Halechiniscidae is represented by 30 species (1 Euclavarctinae, 11 Styraconyxinae, 12 Tanarctinae, 3 Halechiniscinae, 2 Florarctinae and 1Dipodarctinae). This family comprises 87.87% of the specimens sorted out so far. Specimens from the subfamilies Tanarctinae (46.63%) and Styraconyxinae (31.54%) are dominating. Batillipedidae is represented with 3species (8.63% of the specimens) and Coronarctidae (1.89%) and Stygarctidae (1.61%) with a single species each. Samples with similar sediment from 104—260 m depth have similar species distribution in the families. This implicates that the sediment is the key factor involved in the species distribution and that depth is less important. The calcareous sediment is a unique substrate and the tardigrade fauna of the Faroe Bank can be compared with that of sub-tropical and tropical coralline sand. The composition of species exhibits a strong taxonomic affinity with the tardigrade fauna from more southern latitudes, i.e. the Mediterranean Sea and the south-eastern coast of USA.