The yanviru replaced it's ancestor. They now only feed on the oceanvar because they're photosynthesizing proteins are closer to that of the yanviru than that of the kyanos. They are smaller, using their small size to latch on to the cells of the oceanvar. They drain them of all cellular fluids, swelling to the size of a normal yanprobi, then split. Like their ancestors they use the proteins to activate the brown photoreceptive organelles in their cells known as "brunoplast."