Deep-Water Benthic Polychaetes (Vigtorniella Zaikai and Protodrilus sp.) in the Black Sea as Indicators of the Hydrogen Sulfide Zone Boundary
The Black Sea hypoxic layer, situated near the boundary of the hydrogen sulfide zone, is inhabited by the polychaetes Vigtorniella zaikai, Kisseleva, 1992 and Protodrilus sp., which can serve as indicators of the interface between oxic and anoxic water. The maximum number of polychaetes in the northern part of the Black Sea occur at a depth of 150 m, while near Bosporus, where the flow of the Marmara Sea water enters the Black Sea, the peak depth varies from 150 to 250 m.
Five species of hoverflies of the subfamily Eristalinae (tribes Milesiini and Rhingiini): Criorhina floccosa (Meigen, 1822), Chalcosyrphus eunotus (Loew, 1873), Pocota personata (Harris, 1780), Cheilosia psilophthalma Becker, 1894 and C. reniformis Hellén, 1930, are recorded from Ukraine for the first time. Distribution of these species is discussed and diagnoses of Cheilosia species are provided.
Seven hoverfly species of the tribes Brachyopini and Merodontini (subfamily Eristalinae): Brachyopa maculipennis Thompson, 1980, B. plena Collin, 1939, B. vittata (Zetterstedt, 1843), Myolepta obscura Becher, 1882, Orthonevra geniculata (Meigen, 1830), Merodon moenium (Wiedemann in Meigen, 1822) and Psilota atra (Fallén, 1817) are recorded from Ukraine for the first time. Distributions of these species are summarized and diagnoses of the species are provided.
Five species of hoverflies of the subfamilies Pipizinae and Syrphinae: Pipiza accola Violovitsh, 1985, Platycheirus nielseni Vockeroth, 1990, P. occultus Goeldlin, Maibach and Speight, 1990, Epistrophe olgae Mutin, 1990, and Xanthogramma laetum (Fabricius, 1794) are recorded from Ukraine for the first time. Distributions of these species are summarized and diagnoses of the species are provided.