Slime mould (Physarum polycephalum). Coloured scanning electron micrograph (SEM). This is the plasmodium phase of the slime mould's life cycle. It is a single, huge cell with multiple nuclei. It can move slowly, feeding on bacteria, fungi and decaying matter. Some species can seek out certain types of food. In poor conditions, the plasmodium produces mushroom-like fruiting bodies. These release spores that germinate into free-living, single-celled amoebas. These eventually fuse to produce new plasmodia. Slime moulds were once thought to be fungi, but are now classified separately. Magnification: x1000 when printed at 10 centimetres across.