The newly discovered species of microbes can be divided into two groups: the nibblerids, that nibble off small pieces of their prey, and the nebulids, that gobble up their prey in one go.
Predators are essential
Predators are essential to the balance of ecosystems. A well-known example is the reintroduction of the wolf in Yellowstone National Park. That brought on a snowball effect of consequences. The end result was a healthy ecosystem that even changed geographically after the reintroduction of the predator. Microbial predators are similarly essential for keeping the microbial communities in balance.
How did the researchers discover these microbes? By taking samples from marine habitats around the world, they discovered microbes with two tails, flagella, that could swim very fast. In the samples where these microbes were present, all other microbes disappeared within a few days. They were eaten.
New branch in the Tree of Life
The researchers analysed the DNA of these microbes. The genome of these microbial predators was found to be incredibly different from all other life on Earth. They form a separate branch on the tree of life. Until now, it consisted of three main branches: bacteria, archaea and eukaryotes. In addition, a number of new branches have been discovered, most recently, these predators. This branch has been named 'Provora' by the researchers. It is not often that a whole new branch is added,. That makes this research all the more groundbreaking.
Tikhonenkov, Denis V., et al. "Microbial predators form a new supergroup of eukaryotes." Nature 612.7941 (2022): 714-719.