Influence the North-western Part of the Black Sea Habitat Factors on the Meiobenthic Polychaetes

In pseudomeiobenthos, juveniles of 28 polychaetes species were recorded, of which Alitta succinea (Leuckart, 1847), Polydora cornuta Bosc, 1802, and Prionospio cirrifera Wiren, 1883 dominated in density. Based on the results of analysis of variance (ANOVA), a significant dependence of the variability of the alpha-diversity of juveniles of polychaetes on the type of substrate and the temperature of the bottom water layer was established. It is shown that the local diversity of polychaetes juveniles is the highest on the shell (here we refer to the type of substrate) and decreases with increasing degree of substrate silting. With an increase in the temperature of the near-bottom water layer, the alpha-diversity of juveniles of polychaetes increases, which is associated with the timing of reproduction of most polychaetes species. A close positive correlation was found between the densities of juveniles and adults of P. cornuta. This confirms the important role of the presence of P. cornuta settlements in the macrozoobenthos in the selectivity of their locations by pelagic larvae during transition to the bottom. It has been established that in the study area, the active transition of pelagic larvae of polychaetes to the bottom occurs at a depth of up to 40 m.