Distribution and ways of dispersion of American rotifer Kellicottia bostoniensis (Rousselet, 1908) (Rotifera: Brachionidae) in waterbodies of European Russia

Аннотация

In the first decade of the 21th century, the findings of a new invader, the American rotifer, Kellicottia bostoniensis (Rousselet, 1908), has become more frequent in Russia. By 2015 K. bostoniensis had been detected in more than 40 different waterbodies and watercourses of European part of Russia. American rotifer is a widely spread and common species in forest lakes and rivers of the Baltic Sea basin, Volga-Baltic watershed; in the Volga River basin it has spread southward to 55° N (lakes of the Oka and Pra rivers) and eastward to 45° E (the Kerzhenets River, Cheboksary Reservoir basin). The rotifers inhabit small (<3 km²) and large (>200 km2), shallow (<1 m) and deep (>20 m) waterbodies with a trophy range from oligo- to eutrophy. In Russia K. bostoniensis occurs in a wide range of color of water (30–680 degrees Pt–Co-scale) compared to waterbodies of Western Europe. The rotifer is tolerant to temperature regime and oxygen concentrations in water. In the hypolimnion of stratified lakes, K. bostoniensis reaches high abundance (>100000 ind./m3) at a very low concentration of dissolved oxygen (2.5 mg/L or about 20% of saturation) and water temperature of 5–12°С. The invader and aboriginal species K. longispina coexisted in deep lakes and deep parts of reservoirs (the depth more than 5 m); in shallow lakes only K. bostoniensis was found. On the contrary, in most parts of large reservoirs of the Upper Volga only K. longispina was recorded. The possibility and the direction of transfer of the rotifer by swimming birds are discussed.