I've always wonderred if the food-chain in the microscopic world is like that of the macroscopic animal world: are there plants-herbivores-omnivores-predators down there? Even single-celled organisms?

Another way to ask this question is what is the smallest appex predator? What does it look like, what does it eat, does it 'stalk' its prey, how does its prey detect it and defend itself?

I've never been able to find an anwser, so thanks!


I can't say authoritatively that there isn't something smaller but I believe Bdellovibrio (https://en.wikipedia.org/wiki/Bdellovibrio) is an organism you might be interested in. Its a bacteria (single-celled) that invades other bacteria and eats them from the inside. Some amoeba are also predatory, they're somewhat larger and instead act by ingesting smaller cells. I'm interested if other people have thoughts on this!

Agreed but this also depends on how one defines predator. If its animals that prey on others then bacteria are excluded. If it is broadened to organisms then bacteria and phage are definitely included.