Members of the order Anaeroplasmatales can appear as different shapes at different times in their life cycle. Cells which are 16–18 hours old tend to be cocci shaped. By the time the cells are older, they can take on various shapes. Anaeroplasmatales are not motile. Anaeroplasmatales cannot grow in the presence of oxygen. They do grow at a temperature of 37 °C on microbiological medium, where they form irregular-shaped colonies with a "fried-egg" appearance, similar to other mycoplasmas. Anaeroplasmatales are negative by Gram stain.