Rotifers of Inter-Forest Springs

Abstract

Springs are often considered as “hotspots” of aquatic biodiversity. However, small organisms, such as rotifers, substantially contribute to secondary production, but they are rarely investigated in springs. We surveyed the rotifer fauna of 47 springs in the Knyszyn Forest (north-eastern Poland) in summer and autumn 2014–2015. We hypothesized that stream communities of Rotifera may be specific to this habitat. Rotifer samples were taken using a Plexiglas tube in the spring current. Concurrently, water temperature, pH, conductivity, water redox potential and phosphorus and nitrogen concentrations were determined. The springs did not differ statistically in water quality and were stable regarding their temperature and conductivity. Rotifer densities and mean number of monogonont species were very low both in summer and autumn. Nevertheless, the total number of species recorded in all springs was relatively high and accounted for 101 in total. Although strongly differentiated, the rotifer fauna contained a set of several species common to most of the springs. Most of the recorded species are eurytopic and widely spread in water ecosystems. Only the concentration of magnesium and chloride ions had an impact on Monogononta numbers.