Surface: Tryblionella hungarica (Nitzschioid diatom) occupied 90% of mats surface, forming granulated, mucilaginous mass. Cyanobacteria took the rest 10% of surface. 1 layer. Surface white layer is uneven, bumpy, ~ 0.2 mm, composed mostly from Tryblionella hungarica. 2 layer. Dark blue-green layer, composed mostly from Coleofasciculus spp. Thickness of the layer is ~ 0.3 mm. 3 layer. Light grey layer. Coleofasciculus spp. mixed with sediments.Thickness of the layer is ~ 0.4 mm. 4 layer. Second Dark blue-green layer. Thickness of the layer is ~ 0.1 mm. 5 layer. Second light grey layer, mostly composed from sediments and dead cyanobacterial filaments. Thickness of the layer is ~ 0.3 mm. 6 layer. White layer, probably composed from sediments. Thickness of the layer is over 4 mm. TOTAL THICKNESS OF THE MAT IS ~ 1.4 mm. Note: In the longitudinal axis mat is not continuous (discrete). ________________________________________________________________________________________________________________________________________________ Species abundance depending on layer: Species 1st layer Second layer 3d layer ___________________________________________________________________________________________ 1. Lyngbya confervoides 40% 5% 50% 2. Coleofasciculus chthonoplastes 20% 20% 50% 3. Coleofasciculus sp. 40% 25% 4. Spirulina sp. rarely 5. Spirulina tenerrima rarely 6. Anagnostidinema sp. rarely 50% 7. Jaaginema sp. rarely rarely 8. Leptolyngbya sp. rarely 9. Trichocoleus sp. rarely 10.Pseudanabaena sp. rarely TOTAL 10 5 2