Coelomoron tropicalis, a new cyanoprokaryotic species from Sao Paulo State, Brazil

Several populations of a colonial cyanoprokaryotic organism were found in planktic and metaphytic samples collected at four localities in the central part of Sao Paulo State, Brazil (tropical zone). These organisms were identified as belonging to the genus Coelomoron because the cells are mainly obovoid and radially and peripherally situated in the colony in more than one layer, without stalks joining them. The typification of this genus (and the cyanoprokaryotic character of the type species) is not yet finally solved, but the four other species assigned to this genus are typical cyanoprokaryotes. Comparing our populations with the described species, we conclude that these represent a new species due to the smaller size of the colonies and the shape and dimensions of the cells. A key for the identification of all species of the genus is presented.