Observations of Ebria tripartita (Schumann) Lemmermann in Baltic sediments

Sediment finds of Ebria tripartita (Schumann) Lemmermann in the Baltic Sea are reported and light and electron micrographs of the remains of the taxon are presented. Stratigraphic ebriid analysis performed on two sediment cor es (one from the deep Gotland Basin and the other from the shallow Toolo ba y, central Helsinki) provided clear indications of frequency changes of E. tripartita. These changes are apparently related to the variations in troph ic status and salinity, yet competition and degree of preservation may also have contributed to the distributions. Due to identification problems, the species may actually be more common in the sediment material of the Baltic Sea than has hitherto been recognized. E. tripartita may have a significan t potential as an indicator species in paleolimnological research as more i nformation is gathered about its present-day ecological requirements.