Dolphins, the aquatic mammals, are known for the acrobatic leaps that they make out of the water and also for their stunning performances in various shows. They have been very friendly to humans since time immemorial. They are helpful and playful by nature, and are quite energetic too. Trained dolphins can be quite entertaining and so are commonly seen in aquariums, TV shows, and movies. You must have observed that they need to come to the surface for breathing.