Honcharov H. Formation of the fish fauna in the Siversky Donets River Drainage water ecosistems

Author created list of fish fauna and determined current fish composition in the Siversky Donets River drainage. Taxonomical, ecological and faunistical analyses were undertaken too. Main features of fish сomposition dynamics were obtained. Also, comparison of fish faunas of hydrologically divided sections and groups of water bodies and search of main features for general distribution of fish over the both reservoirs and watercourses were achieved. In addition, comparisons of fish assemblage of three test river section in different rivers and of the same test river section for five years were carried out. Both main causes of current fish fauna state and level of effects for each of them were ascertained too. For the first time after 1927, was confirmed that racer goby Babka gymnotrachelus is resident for river basin. For the first time, was recorded appearance of stone moroco Pseudorasbora parva, pumpkinseed Lepomis gibbosus and bighead goby Ponticola kessleri in the river basin as adventive species. The first record of adventive Black Sea sprat Clupeonella cultriventris in the Kharkiv Region was carried out too. As well as vectors of their penetration to the modern fish complex of the river drainage were analyzed. Five guidelines on further research and nature conservation activity were proposed in order to save and restore biodiversity of fish. Concrete nature conservation arrangements were justified and argued.