The conception of lungs
In order to breathe in air the mudskipper retains water in its mouth which swills over the limning of it. The African Lungfish Protopterus (Order Dipnoi) can burrow into mud, curls itself into a ball and secretes mucous which creates a parchment-like case around the hole it has encased itself in and avoid desiccation during the dry season. The lungfish has a pouch opening from the gut (similar to the primitive bichir fish) which functions as a lung and extracts air from the tube it created when burrowing through the mud. By flexing its throat muscles the fish draws air into its pouch which is supplied by numerous blood vessels which absorb gaseous oxygen. With the termination of the dry season the fish returns to an aquatic existence and breathes with its gills, but like the Bichir may take gulps of air if a lack of oxygen develops.