OLIGOCHAETA IN SPARTINA STEMS - THE MICRODISTRIBUTION OF ENCHYTRAEIDAE AND TUBIFICIDAE IN A SALT-MARSH, SAPELO-ISLAND, USA

The distribution and abundance of Enchytraeidae and Tubificidae in and around Spartina alterniflora plants in a tidal salt marsh on Sapelo I sland, Georgia, USA were studied using two different sampling techniqu es: wet funnel extraction and stem dissection. At least 80 % of all wo rms inhabited leaf sheaths at the bases of S. alterniflora plants, and densities were low in sediment, root and surface debris samples. Olig ochaete densities were dependent on the position within the marsh, the height on stems and the stage of sheath decay. Six predominant specie s were identified and included Marionina appendiculata, Marionina spar tinae, Marionina waltersi, Marionina paludis, and Monopylephorus parvu s. Individual species were distributed differently on stems and enchyt raeids were more common than tubificids on standing-dead and further u p S. alterniflora stems. Estimates of oligochaete densities in salt ma rsh habitats are increased dramatically when the numbers of worms on s tems are considered. Possible advantages of the stem microhabitat are discussed in relation to the biology and ecology of oligochaetes.