Kellicottia bostoniensis (Rousselet, 1908) and K. longispina (Kellicott, 1879) (Rotifera: Brachionidae): Features of Occurrence and Distribution in the Lakes of the Upper and Middle Volga Region

Various water bodies of the Upper Volga River (Yaroslavl oblast, Russia) and the lower course of the Sura River (Middle Volga) are found to be inhabited by closely related rotifer species: native for both studied regions K. longispina and alien K. bostoniensis. Both species occur all year round; however their highest abundance is detected in spring or autumn. Alien rotifer K. bostoniensis has been found not only simultaneously with indigenous rotifer species but also separately, in more shallow water bodies. Alien species is more tolerant to bathymetry, basin form, transparency, and the trophic state of the water body. Probably, these features facilitate wider distribution of K. bostoniensis in the Sura basin water bodies compared to indigenous species. Alien K. bostoniensis spread relatively quickly in the Sura basin without affecting closely related indigenous species, to which it is not a competitor.

Automated summary

This study found that both native and alien rotifer species coexist in the water bodies of the Upper Volga River and the lower course of the Sura River. The alien species, K. bostoniensis, is more tolerant to various factors such as water depth, basin form, transparency, and trophic state, which allows it to have a wider distribution compared to the native species. The alien species spread relatively quickly in the Sura basin without impacting the closely related indigenous species.