Polychaeta

Sergeeva, Nelli G. & Mazlumyan, Sofia A., 2015, Deep - water hypoxic meiobenthic Protozoa and Metazoa taxa of the Istanbul Strait’s (Bosporus) outlet area of the Black Sea, Ecologica Montenegrina 2 (3), pp. 255-270 : 265-266

2.2. Polychaeta

The distribution of Polychaeta abundance in the depth range 75–250 m is very uneven. In the distribution of Polychaeta marked peaks occurred at the depth 88, 162 and 250 m. Maximal abundance value of Polychaeta reached up to 9360 indiv.*m -2 at the depth of 88 m, the second largest peak of polychaetes inhabitation (7280 indiv.*m -2) occurred at the depth 250 m ( Fig. 13). At the depth 162 m polychaetes almost entirely were represented by young individuals of species Vigtorniella zaikai Kiseleva and Protodrilus sp. Usually, these species inhabited suboxic layer and upper border of the hydrogen sulfide ( Zaika et al. 1999, Zaika & Sergeeva 2008). At the depth 250 m of polychaetes only species V. zaika was found, whereas in other parts of the Black Sea this species had its maximum of abundance at a shallower depth (150–170 m) ( Zaika & Sergeeva 2012). The planktonic larvae of V. zaikai dwell in layer with certain physical and chemical characteristics. They occurred in all studied samples of near bottom water, sediment surface detritus and in the upper layer (0–3 cm) of sediment ( Fig. 14 ).

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0-1 cm 1-2 cm 2-3 cm 3-4 cm 4-5 cm 5-7 cm Depth (m)

Figures

Figure 14. Proportion of polychaetes inhabiting different sediment layers along the depth gradient.