Oligochaetes of the Karavasta Lagoon (Albania). Preliminary results.

In a study of the composition and structure of the benthic community of the Lagoon of Karavasta (Albania),carried out in June 1996, a peculiar distribution of oligochaetes was observed. Four species of tubificids were collected, together with 32 species of other benthic invertebrates (crustaceans, polychaetes, molluscs, nemerteans and chironomids). The oligochaete species found are well-known for the Adriatic coast. Their distribution in the lagoon was mostly restricted to a longitudinal zone near the sea and their densities decreased landwards, to be completely replaced by other faunal groups (particularly chironomids and molluscs). Zonation was distinct according to a salinity gradient and variable hydrodynamic and sediment characteristics.