Aiptasia are unusual beasts. To a naive eye, these palm-like anemone could easily be confused for plants. In fact, aquarists often refer to them as weeds, owing to their ability to rapidly grow and multiply in seawater aquaria. These creatures are most definitely animals. However, they do serve as a home for photosynthetic algae (dinoflagellates). In this symbiotic relationship, the algae provide energy (e.g., lipids and sugars) for the anemone in exchange for protection and nutrients. Within this sea of relatively large adults, I found a tiny, foldscopable polyp. almost invisible to the naked eye.

I mounted the tiny polyp on a glass slide, usinng a ring of wax to act as a well.

Symbiosis in action! I was shocked to make out individual dinoflagellates (the round balls) in the anemone’s tentacles. Not only that, many of these symbionts appeared to be rapidly traveling on internal highways. I wonder what the purpose of this rapid circulation is, and what sort of internal plumbing in the anemone would give rise to such interesting internal flows.