Deep sea bacteria (blue) on the surface (yellow) of annelid worms (Alvinella sp.). These bacteria are chemosynthetic, which means that they produce energy from chemicals instead of from sunlight. They use sulphide compounds in the water produced from deep sea hot water vents. The bacteria may be a source of food for the Alvinella sp. worms. In addition, they may remove chemicals from the water, thus making the environment more hospitable for the worms. These bacteria usually live in temperatures of between 50 and 60 degrees Celsius, but can withstand up to 105 degrees Celsius. Magnification unknown.