Hello folks,
Due to a childhood obsession with exotic animals I've been able to recognize (if not name) most of the creatures I see in Aquaria.

Screenshot of the angler fish is at the "tongue", just outside the entrance to the Body.
(If you're curious, the book is:)

However I have no idea what these things are:

Or why they're in bubbles, or why they shrink when I shoot them... Any help?

You can find them in the Abyss, along the path which leads to the Sunken City. They don't seem to damage me, even when I run into and through them with wild abandon.
P.S. I don't know if this is the right place to post this topic.