Are Dolphins Self-Aware?

Human babies between 18 and 24 months old don't realise when they are looking in a mirror; they think they are looking at another child. 

Scientists argue that you don't recognise yourself in a mirror until you are aware of yourself as an independent, self-conscious being.

When Ken Marten put a spot on a dolphin called Keola, so that he could only see the spot when looking in a mirror. Keola clearly twisted and maneuvered himself while looking in the mirror in order to see the spot.

This behaviour was quite different to how Keola would react to a new member of the group. 

Similar experiment with mirrors and zinc spots on the backs of dolphins -- After the scientists started removing the zinc spots from the backs of the dolphins, they would swim back to the mirror to check that the spot had gone.

The dolphins did not react to their reflection as if they were seeing another dolphin. It's worth remembering that dolphins do not recognise each by their 'face' and they also use a sort of sonar to 'see', which would not work using a mirror. 

So dolphins looking in the mirror is all the more remarkable.

https://www.dolphins-for-kids.com/are-dolphins-self-aware

Whales and dolphin live in water, but they breathe air. 

They have to control their breathing so that they inhale while above the water.

When researchers tried to anesthetize a dolphin, it stopped breathing and died of asphyxiation.

They then tried reducing the amount of anesthetic and changing anesthetics, but to no avail.

Anything that cause the dolphin to go unconscious causes it to stop breathing. 

https://www.quora.com/How-do-we-know-whales-and-dolphins-are-conscious-breathers