Revision of the Black Sea dinoflagelate checklist

As a result of the critical and systematic revision of the Black Sea superclass Dinoflagellata, the checklist was updated. It currently includes 386 species (396 ist), which belong to 5 classes, 17 orders, 51 families and 95 genera. Among them, 39 species are cosmopolitan, 17 are widespread in the world, 8 are euryhaline, 30 are toxic and 35 are bioluminescent. After 2018, 28 new species were found, unique to each water area: 14 for Bulgarian waters, 6 for Ukrainian, 5 for Turkish and 1 each for Russian, Georgian and Romanian. Compared with the previous checklist of 2018, the taxonomic structure of Dinofflagellates has changed significantly due to a more stringent selection criterion for the analyzed sources, as well as the emergence of new taxonomic combinations. New to the Black Sea flora are the genera: Acanthogonyaulax (Kof.) H.W.Graham, Eleftheros Tikhonenkov, Hehenberger & Keeling, Pelagodinium Siano, Montresor, Probert & Vargas, Pfiesteria Steidinger & J.M. Burkholder and Pseudadenoides F.Gómez, R.Onuma, Artigas & T.Horig. Among them are new to science species Eleftheros karadeniz Tikhonenkov, Hehenberger & Keeling and Amphidoma pontica Tillmann & Dzhembekova. The greatest species richness of dinoflagellates, as before, is noted in the Ukrainian sector of the sea (75% of the total number in the sea), which is due to the great diversity of environmental conditions, as well as the high level of study of the water area, the second place is occupied by Turkish waters (51.5%). Georgian and Romanian waters, with minimal areas (6–6.5%) occupy the last places (20.5 and 25.6%, respectively), the share of dinoflagellates in the Bulgarian water area is 35%, and in the Russian — 40.4%. Climate change and the "mediterraneanization" of the Black Sea accelerate the process of introduction of species into this region, in parallel, the intensification of research, with a wider application of modern methods, contributes to the clarification of the data. Over the past 18 years, the number of species common to all water areas has doubled (from 19 to 39), and the number of "blooming" pathogens has increased from 13 to 23. The taxonomic status of 10 species requires additional research. 68 species require verification and additional research. To correct errors that occur in many generalizations, to preserve and accumulate information on species, it is necessary to update the electronic database of Black Sea algae, similar to the site "Prodromus dinoflagellates of Ukraine", created on the basis of the engine medioviki at the M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine. When entering information, the principle of primary sources should be used (enter only original data).