An introduction to a special issue on lotic meiofauna

1. This special issue focuses on the meiofauna of lotic freshwater systems, providing a review of the biology and ecology of this relatively poorly studied constituent of the benthos in running waters. 2. Six papers review the biology and ecology of the major groups of lotic meiofauna: microturbellarians; rotifers and gastrotrichs; nematodes; water mites; microcrustaceans and tardigrades. 3. Current knowledge of the ecology of lotic meiofauna is presented further in six papers that also highlight important future directions for research.