Share Microscopic plankton are at the heart of the ocean’s food chain, feeding much bigger animals like whales. However, not much is known about how single-celled phytoplankton–most of which don’t have any appendages that help them swim–get around. They journey up from the darkest and coldest depths of the ocean up to the surface, only to drift down again. One species of bioluminescent phytoplankton called Pyrocystis noctiluca does this by ballooning six times its normal size. This inflation then takes the usually only a few hundred micron-wide plankton about 656…
