The phrase, ‘Eat your vitamins,’ applies to marine animals just like humans. Oceanographers have found that archaea, a type of marine microbe, can produce B-12 vitamins in the open ocean, a vitamin that is generally elusive in the ocean environment. Once believed to be manufactured only by marine bacteria, the new results show that a whole different class of organism, archaea, can supply this essential vitamin. This study is the first to show that marine archaea, a single-celled organism that evolved totally separate from bacteria and all other living things, are making B-12. Relatives of these tiny critters are known for unusual behavior like living inside hot springs and underwater volcanoes....