How many chambers are present in a Piscean heart?

The number of chambers in the heart depends on the complexity of the body organization. For example, mammals are more complex and therefore, they possess maximum number of chambers in the heart  (four-chambered heart) and fishes have less complex body organization than mammals, so they possess less number of chambers in the heart than found in case of mammals. Piscean - These are fishes. They are exclusively water animals. Their skin is covered with scales/plates. They obtain oxygen dissolved in water by using gills. They are cold-blooded and have two-chambered heart.