ABSTRACT
In a small bay of the Gulf of Arta ( Ambr akikos Ko .1 pos, Ion i an Sea, Greece, Mediterranean), west of the t own Amphilochia, there had established a very special community of echinoderms and other invertebrates. The reason therefore was the very calm sea with nearly no tides, no currents, no waves (larger than 20 cm in summer). So no shells of bivalves, gastropods, no tests of sea urchins and no other remains of the inhabitants of the originally mostly sandy bottom were washed ashore but kept lying at the place of origin where they soon were packed together by red algae and serpulid worms (especially Pomatoceros triqueter) . The result was a special kind of secondary hard bottom that made the coexistence of soft- and hard-bottom dwellers possible, even at a depth of 1 m only.
