The next (spring) stage of field studies of seasonal and daily dynamics of migrations of lampreys of the genus Eudontomyzon took place. Employees of the Laboratory of Behavior of Lower Vertebrates, IEE RAS, Senior Researcher A.V. Kucheryavy, senior researcher A.O. Zvezdin and graduate student A.V. Kolotei conducted daily stations on the rivers of the Smolenskoye Poozerye National Park during the spring flood. In contrast to the winter low water, during the spring rise in water, the larvae of the lamprey of the genus Eudontomyzon make a downstream migration. It begins when the illumination decreases to 2 thousand lux (lx), and the concentration of individuals migrating downstream reaches its maximum values at illuminations of several hundredths of a lux. The presence of larvae of different sizes in the stream indicates that individuals of all age groups are involved in the migration.
These data are consistent with the results of similar studies conducted for complex species - the river Lampetra fluviatilis and the Pacific Lethenteron camtschaticum lamprey, and confirm the validity of the previously proposed life cycle scheme (Zvezdin et al., 2022) also for a species representative of an exclusively freshwater (resident) lamprey genus (Eudontomyzon). The factual material also confirms the exit of migrants from a tributary to a larger river, which ensures the connection of local populations within the river system.
This trip is part of a series of works devoted to the study of the migratory activity of lampreys, as well as to the study of the mechanisms of their distribution. Work will continue in the summer and autumn.
The expedition took place within the framework of the RSF project 19-1400015-п.
