 Their shape is necessary for them to shuttle down into the ocean sediments to find more sulfide and nitrate.In contrast, "Thiomargarita" grow in rows of separate single ball-shaped cells, not allowing them to have the range of mobility that "Thioploca" and "Beggiota" have.With their lack of movement, "Thiomargarita" have adapted by evolving very large nitrate-storing bubbles, called vacuoles, allowing them to survive long periods of nitrate and sulfide starvation.