Micrasterias desmid dividing. Differential interference contrast (DIC) light micrograph of a Micrasterias sp. desmid undergoing mitosis to form two daughter cells. Desmids are a common group of freshwater single-celled algae that have intricate cell walls. Micrasterias can reproduce both asexually (as here) and sexually. Magnification: x280 when printed 10 centimetres wide.