Halococcus bacteria. Coloured light micrograph of a group of Halococcus sp. bacteria. Known also as halo-bacteria, these round cocci occur in highly saline environments such as salt lakes or evaporation ponds. They may be found on the surfaces of heavily salted foods, particularly salted fish or meats. Requiring large amounts of sodium for growth, Halococcus is not pathogenic to humans. The diameter of one organism is approximately 1 micron (one thousandth of a millimetre).