Solibacter oceanensis
Solibacter oceanensis is a descendant of Solibacter riveresnis that arose in the ocean Zone 13 and is the result of S. riveresnis being carried out of the watershed. To adapt for saltwater it has simply stopped removing excess water using vacuoles and matches the salinity of its environment, being able to function in most conditions, though it would still quickly die if the salinity is exceptionally high, such as in a brine pool.
This 2μm cell is found in the substrate or floating in the water. It fixes oceanic nitrogen, fertilizing it, and provides usable nitrogen for itself. It has no nucleus and is receptive to horizontal gene transfer. It can adapt to sudden changes, including even being stranded on the beach at low tide, and its cell membrane and wall serve as protection. While dividing, which it does every 20 minutes, it reabsorbs it's cell wall briefly for a nutrient boost, before rebuilding it once it has finished splitting. It has orange pigmentation.