Rhodospirillaceae

Members of this family are often found in anaerobic aquatic environments, such as mud and stagnant water, though they are capable of surviving in the presence of air. A notable genus, Magnetospirillum, exhibits magnetotaxis. These bacteria contain internal chains of magnetite that allow them to orient themselves along the Earth's magnetic field lines, aiding their movement toward the sediment of ponds where they live. The discovery of similar magnetite structures in Martian meteorites has led to speculation about the possibility of ancient life on Mars.