This is a Pleuronema, a hard to record unicellular organism, it can "jump" away very fast when it's startled by something. In this clip, a tiny alga is bumping into Pleuronema and scaring the bejesus out of it. 😂 . Pleuronema feeds mostly on bacteria, and it runs away when it's disturbed to protect itself from predators, at least that's what I believe. Unfortunately, there are not many studies on them. . It's tough to record it with high magnification objectives because when it jumps, it gets o

This is a marine worm, Dinophilus, and it’s parasitized by unicellular organisms called Grellia. You can see the parasites as blue, banana-shaped structures in this polarized view. . Dinophilus are a few millimeters in length and inhabit all marine environments. They eat algae and mind their own business without bothering anyone. However, the large population I had in one of my fishless tanks were all infected by a species of unicellular organism. . When I checked an odd-looking Dinophilus under