A meiofaunal “thiobios” limited to the anaerobic sulfide system of marine sand does not exist

The spatial relationship of interstitial metazoans to sources of oxygen has been studied on a tidal flat in the Wadden Sea near Sylt (eastern part of the North Sea). Consistently, meiofauna remains in close proximity to oxygenated layers or pocket areas within the sediment. This is exemplified by the pattern of meiofaunal abundance and species composition alongside oxic burrows of the lugworm Arenicola marina L. A specific meiofauna confined to oxygen-deficient horizons of the sediment does not exist.