Periphyton Meyofauna natural stony substrate (Odessa Bay, Black Sea)

For the first time, features of the formation of the total number and biomass of permanent members and temporary members) of meiobenthos in periphyton of natural stony substrates are described for the shelf of the northwestern part of the Black Sea. The material for the scientific analysis was quantitative samples collected during 2012, 2014, and 2015. On two polygons of the North-Western shelf of the Black Sea in the coastal zone of Odessa Bay in the area of the Hydrobiological Station ONU I.I. Mechnikov. Representatives of the following large meiobenthos taxa were found on a stony substrate at a depth of 3–10.7 m: Foraminifera, Nematoda, Ostracoda, Harpacticoida, Halacaridae, Turbellaria, Oligochaeta, young Polychaeta, Bivalvia, Balanus, Amphipod, Cumidae, Crayfish. Kinohryncha and Gastrotricha were absent. The species composition of the main meobenthic groups (Nematoda, Harpacticoida and the young Polychaeta) and their numbers are given. Indicators of the total abundance of meiofauna in the periphyton of the stony substrate varied from 59000 to 341500 ind.·m -2 (average density 156107 ind.·m -2 ), which was dominated by eumeiobenthos, making up 64% of the total number of organisms. At 57% of the stations studied, representatives of the meiobenthos of the harpacticoids dominated in the density of the settlements, which accounted for 53.2–80% of the total number of organisms. Polychaetes belonging to meiobenthos were unevenly distributed in fouling of a stony substrate. Their average number was 18786 ind.·m -2 , an average of 12.7% of the total number of organisms. The share of nematodes in the total number of stones was 20%. Their average density is 23,864 ind.·m -2 . Studies have shown that the biodiversity of the meiobenthic community of organisms in the periphyton of natural stony substrates is much poorer than on the loose soils of the adjacent water areas.