The 4 steps of ventilation via buccal pulse pump in African and Australian lungfish

Step 1- The lungfish points it's head and mouth out of the water. It then opens its mouth using the sternohyoideus and expanding its buccal cavity taking air into its mouth. The mouth remains open.

Step 2- The lungfish opens its glottis allowing the air in its lungs to exit out its mouth mixing with the air in its buccal cavity. The air is able to exit the lungs through elastic recoil and contraction of smooth muscles.

Step 3- The mouth closes and using brachial constricting muscles and the lungfish forces the mixed air into its lungs

Step 4- The lungfish closes its glottis and hold the air into its lungs. The lungfish then submerges.