Contentment in a container?

This handsome fellow, or lady, stole my heart.

I stared at the sea turtle through the layered glass for maybe 15 minutes, until I felt I had to move along on the walkway in the aquarium to encounter whatever was next. Folks elbowed their way around me to get their best views of the turtle and its fellow captured creatures.

The sea turtle seemed to stare back at me as I edged away. I snapped this one photo of it.

I know the fish, the turtle, the shark, they are being held hostage. But do they? I also know they are hostage in a good home, with attentive care, proper water temperatures and likely all the food they need.

They are likely content, but they are confined. From my side of the glass, looking through at them, I wonder if they want to be free. Are they aware they are confined? In a container? Or are they the contented ones in the container who wonder about those wandering creatures who nearly continuously move along on the other side of the glass?