Spatial and temporal distribution of <em>Kellicottia bostoniensis</em> (Rousselet, 1908) (Rotifera) in a big tropical reservoir (Furnas Reservoir), state of Minas Gerais, Brazil

Abstract

The rotifer Kellicottia bostoniensis is a common planktonic species in North America. This species has been introduced in Brazil recently. It is found in southeastern Brazil in a small eutrophic reservoir in Belo Horizonte (Minas Gerais state capital) and in the Rio Grande Basin, Furnas reservoir (20^º 40’ S- 46^º 19’W). The aims of this study is to analyze this rotifer spatial and temporal distribution along a trophic gradient in 12 locations (3) in the reservoir central axis and (9) in one of its main tributaries, the Sapucaí River axis. The samplings were taken in August and October, 1999, and in March and July, 2000, through vertical tow, with a 68 µm cylindrical-conical net. The organisms were counted in a Sedgwick-Rafter cell. This rotifer was in the whole sampled area, and the higher densities were observed in October and March, rainy season, in the meso and eutrophic areas. The K. bostoniensis occurrence in this reservoir possibly reflects its high adaptability to tropical environments.