AUSTROPOTAMOBIUS TORRENTIUM (SCHRANK, 1803) IN THE AGGITIS CAVE (NORTHERN GREECE).IS IT A CAVE-DWELLING SPECIES?

摘要

Although the stone crayfish, Austropotamobius torrentium (Schrank, 1803), is widespread in central and southeastern Europe, including Greece, it has not been recorded living deep inside caves before. Recently, however, it has been recorded from a variety of depths inside the Aggitis Cave in northern Greece. The crayfish have been found in the out flowing River Aggitis, in the entrance to the cave, as well as at 2,100 m and 7,100 m from the entrance. The crayfish found were pigmented in general, although those from the deeper parts had characteristically bluish pereopods. The finding of crayfish so deep inside a cave system is unusual, and is probably the deepest record so far in Europe and North America. The origin of the deep-dwelling crayfish is unknown. Although they occur above the cave system, it is unlikely that they could have entered the system from there in recent times due to a build up of sediment, but they may have become trapped in the cave prior to this happening. Alternatively, they may have moved upstream into the cave system over time. It is hoped to determine whether they complete the whole of their life history in the cave system and what they are feeding on.