Picozoa were first detected using
18S ribosomal RNA genes in 2007. The identity of new organisms was deduced from a comparison of familiar and unfamiliar gene sequences. "The gene sequences found in these algae could not be associated with any previously known group of organisms", explain Klaus Valentin and
Linda Medlin, co-authors of the study and
molecular biologists at the
Alfred Wegener Institute for Polar and Marine Research in
Bremerhaven. The algae in this study were found in plankton samples originating from various regions of the North Atlantic and the Mediterranean. The scientists have discovered a group of organisms which, despite being completely new to science, have a wide distribution. "This is a good indication for how much there is still to discover in the oceans, especially using molecular tools", says Valentin. In
red algae, for example, these proteins occur as pigments. But in this newly discovered group of algae, the phycobiliproteins appear to be contained inside the
plastids, where the
photosynthesis occurs. Hence, it provides a clear indication that the researchers are dealing with previously unidentified group of algae. Referring to their small size and the presence of phycobiliproteins, the researchers named the new group Picobiliphyta. A study later in 2011, conducted by researchers at
Rutgers University and
Bigelow Laboratory for Ocean Sciences, used whole genome shotgun sequence data from three individual picobiliphyte cells to show absence of plastid-targeted or photosystem proteins within the fragments of nuclear genome sequence they reconstructed. This again suggested that picobiliphytes are
heterotrophs. In 2013, Seenivasan working in conjunction with
Michael Melkonian (University of Cologne) and Linda Medlin (Marine Biological Association of the UK) formally described the picobiliphytes as the heterotrophic nanoflagellate phylum, Picozoa, and published thin sections of the cells. Several unique features in the cell, such as a feeding organelle, unusual movement, and heterotrophic mode of nutrition, substantiate their unique phylogenetic position. No traces of viral or bacterial particles were found inside these heterotrophic cells, which prompted these authors to suggest that they feed on small organic particles. == See also ==