ИСТИНА

Cymodoceaceae is a family of sea grasses (5 genera, 17-18 species) common in tropical and subtropical littorals.With the aim to reconstruct the processes of historical distribution of Cymodoceaceae the complex morphological and molecular genetic analysis was carried out (36 morphological features and 5.8S ribosomal RNA gene) for 9 species of all genera of the family. Scheuchzeria palustris F. Muell was chosen as an outgroup. Using the WinClada program and bootstrap analyze, “molecular”, “morphological”, and “complex” cladograms were built for Cymodoceaceae. The complex cladogram was obtained as a result of combining molecular-genetic and morphological data matrix; it became the basis for reconstruction of the history of current distribution of Cymodoceaceae in combination with paleobotanical data. The oldest representatives of Cymodoceaceae (genera Amphibolis, Halodule, Thalassodendron) supposedly arose in the tropical waters of East Gondwana (Australia-Antarctica) in Cretaceous and later settled along the World Ocean by various tracks, the most important of which passed along the southern coast of Eurasian continental masses (through the "residual pool" of Tethys) and reached the waters of modern Atlantic. More advanced genera Cymodocea and Syringodium originated in these areas and moved “back” to the waters of the Indian Ocean and the southwestern Pacific.