New Information on the Findings of Alien Rotifer Kellicottia bostoniensis (Rousselet, 1908) (Rotifera: Monogononta: Brachionidae) in Nizhny Novgorod Oblast

The hydrobiological studies carried out in 2017 and 2018 yielded new information on the distribution of the alien species Kellicottia bostoniensis (Rousselet, 1908), discovered in five different-type rivers. This species was found in these rivers for the first time. In the Gnilichka, Vyunitsa, Chernaya, and Kerzhenets rivers and also in the Cheboksary Reservoir, the rotifer was reregistered. The lower reach of the Vetluga River is at the same time the easternmost and northernmost location where this species was found in Nizhny Novgorod oblast. The paper analyzes the findings of K. bostoniensis in the floodplain lakes of the Kerzhenets River, which are new habitats of this species in Nizhny Novgorod oblast. It has been found that rotifers are common in water bodies with various depths and different morphometric and physicochemical parameters. For the first time K. bostoniensis is registered in the water bodies of European part of Russia with a water color index of more than 1000 degrees (Lake Novaya Staritsa—1245.0 deg), as well as in the waters with a low content of dissolved oxygen (0.2 mg/L—Lake Novaya Staritsa).