(I couldn’t have gotten the indoor aquarium shots without a fast lens. Whatever this is, I shot it at f/1.4.)
I’m pretty confident it’s a sea anemone, or rather a whole bunch of them, but I can’t get more specific with any certainty. You don’t recall which area this was in, do you? (If it was in the BC coast exhibit, it might be a strawberry anemone (Corynactis californica), or so the internet leads me to believe).