Scientists have discovered the world's largest known bacteria, reaching up to one centimetre (0.4-inches) in length. The species, called Thiomargarita magnifica, was discovered on sunken leaves in the waters of a mangrove swamp in Guadeloupe, Lesser Antilles in the Caribbean. It appears as thin white filaments like vermicelli pasta, and contains microscopic sulphur granules that scatter light, giving it a pearly gleam. T. magnifica is a sulphur-oxidising prokaryote, meaning it derives energy from the oxidation of sulphur compounds. Large sulphur bacteria have been shown to be hot spots for symbionts – an organism living in symbiosis with another. Another species...