The ancient extant Lungfish can breathe oxygen from air and can remain in
The Dipnoi, a group of
These primitive living fishes first appeared in the Early Devonian Epoch (about 419.2 million to 393.3 million years ago). Historically, these lungfishes are also known as salamanderfish.
All lungfishes have snake-like bodies. The base
The fossil record shows the existence of seven known families of lungfish. Among these, only three of them survive now at Africa, South America
These may grow up to 4 feet long. They have large flipper-like fins and large scales that distinguish them from its other species.
These fishes have the ability to survive for prolonged periods out of
Afican lungfishes are the largest which can grow to a length of about 7 feet that have two lungs with external gills, which they lose at a certain age.
The South American Lungfish is different due to its elongated body and may grow up to 4 feet. These are atmospheric air breather,still it does not create mucous cocoon while undergoing aestivation.
Primitive lungfish groups retain marginal teeth and an ossified braincase while derived fishes show a significant reduction in the marginal bones and a cartilaginous
They have a highly specialized respiratory system. Their
As the water passes through the gills of lungfish, they use a buccal pump. This is a unidirectional path flow through the mouth and gills. During air breathing, the sixth gill is used for respiration and also for passing the deoxygenated blood before reaching the lung.
The lungfishes are close relatives of tetrapods as they
Being omnivorous, they eat aquatic animals including their own species. When they become adults, their teeth fuse together to form tooth plates to chew their food.