The Crescent/Frond symbiote I’m working on for Almost Real, here in some greater detail as the design develops.
In the front, you can see the Crescent’s ports open, trailing the Fronds behind, as they exchange oxygen for carbon dioxide and filter feed from the surrounding water. Behind, you can see another individual hunting, its gills saturated and ports closed to reduce drag, using its harpoon/umbilicus to snag a small creature to eat. It look like it missed.