THE DEEP-SEA NEMATODE THALASSOMONHYSTERA-BATHISLANDICA SP-NOV AND MICROHABITATS OF NEMATODES IN FLOCCULANT SURFACE SEDIMENTS

Thalassomonhystera bathislandica sp. nov. (Nematoda: Monhysteridae) wa s found in abundance in a few gelatinous phytodetritus aggregates coll ected from the surface of bottom sediments in the north-eastern Atlant ic at depths of about 4000 m. The new species resembles T. islandica ( De Coninck, 1943), an inhabitant of saltmarshes. Viscous detrital aggr egates, including sediment agglutinations made by the nematodes themse lves, are perceived as the preferred habitats of nematode species in f luffy surficial muds. It is suggested that physical constraints preven t nematodes from a fast invasion into freshly sedimented, loose detrit us deposits.