Researchers have uncovered the first example of a food chain connecting archaea, a type of single-celled microrganism that contains no nucleus or any other membrane-bound organelles. In order to see if archaea are a viable food source, the researchers fed worms a diet that included two strains of archaea. The worms, called Ophryotrocha labronic, were found to grow at the same rate whether they were on the archaeon diet or a bacterial or eukaryotic food diet. Since archaea consume methane, researchers tracked the isotopic signature of the methane found in the archaea to that found in the worms, thereby establishing that this kind of feeding occurs in the wild.
