How many heart chambers do osteichthyes's have?

Amphibians have three heart chambers: two atria and a single ventricle.

• The atrium receives deoxygenated blood from the blood vessels (veins) that drain the various organs of the body.
• The left atrium receives oxygenated blood from the lungs and skin (which also serves as a gas exchange organ in most amphibians).
• Both atria empty into the single ventricle.