Rotifer any of the members of Rotifera, a minor phylum of animal kingdom composed of microscopic multicellar organisms recognisable by an anterior ciliary organ, known as corona. These minute organisms, also known as wheel animalcule, are principally inhabitants of freshwater bodies, though occasionally reported from salt water, and moist terrestrial habitats. These interesting animals constitute most important food item for the fishes.
Many species of rotifers have been identified from different types of freshwater bodies in Bangladesh. Brachionid rotifers seem to be predominant and the common species recorded are Brachionus diversicornis, B. falcatus, B. quadridentatus, B. calyciflorus, B. havanensis and B. forficula. The other common genera in Bangladesh are Keratella, Monostyla, Lecane, Lepadella, Filinia, Trichocerca, Polyarthra, etc. [Abdul Maleque Bhouyain]