In an article  entitled, ‘Pandoraviruses: Amoeba Viruses with Genomes up to 2-5 Mb reaching that of Parasitic Eukayotes”  published in 19th July, 2013   issue of Science, Chantal Abergel and 12 associates affiliated to two institutions at France and one at Sweden determined the upper limit of the viral world, both in terms of particle size (>0.7 micrometers) and genome complexity (>1000 genes) typical of parasitic bacteria determined from a variety of aquatic environments. They reported the isolation of two giant viruses, one off the coast of central Chile, the other from a freshwater pond near Melbourne (Australia). They detected  no morphological or genomic similarities  between the  two recently discovered  viruses to any previously defined virus families. The presence of  minute  ovoid particles  was found to contain DNA genomes of at least 2.5 and 1.9 megabases, respectively. These viruses are the first members of the proposed “Pandoravirus” genus, having had no resemblance with  any previously described microbes. They are characterized  by  their lack of similarity with any previously described microbes.