Biocenotic composition of the macrozoobenthos on different habitats from the littoral region of Lake Ohrid.

Biocenotic research on the benthic fauna from the northwestern part of Lake Ohrid, has shown that different habitats characterize different qualitative compositions of the benthic fauna. The affinity of the macrozoobenthic communities to populate different habitats was investigated in 5 different localities from the northwestern part of Lake Ohrid. Among the five different types of habitats such as stony bottom, sandy bottom, sandy-muddy bottom and muddy bottom mostly covered with mollusc shells, it was found that from the qualitative point of view, the sandy-muddy bottom covered with vascular macrophytes is characterized with highest biodiversity of benthic fauna. In all localities, with the exclusion of the locality As (where the macrophytic vegetation is not well developed), the maximum number of species was recorded between depth points from 3 to 11 m. In the Radozda locality, the maximum number of species (11 species) was recorded at a depth point of 6m., on a bottom covered with sandy mud. In the Livadishte locality, the highest biodiversity (13 species) was recorded at a depth points of 5 and 11 m., on bottom covered with sandy mud with well developed macrophytic vegetation. The localities Kalista and Struga, the maximum number of species (14 in Kalista and 11 in Struga) was also recorded in the same type of habitat, a sandy-muddy bottom with well developed macrophytic vegetation.