None. The sea squirts have a unique tube shaped heart with vessels occasionally called channels, but no chambers.
Four.
We humans have one heart with four pumping chambers.
The four-chambered pig heart has two atria (left and right) and two ventricles (left and right).
They are the two upper chambers of the heart
The Atrium are upper chambers of the heart.
There are 4 chambers to the heart.
Their are 2 heart chambers.
A shark heart has two chambers.
Penguins have 4 chambers in their heart.
The bird's heart has 4 chambers.
The heart of fish have two chambers. The heart of reptiles and amphibians have three chambers. The heart of mammals have four chambers.
A perch has two chambers in it's heart.
There are 4 chambers in a bird's heart.
A sheep heart has four chambers.
There are four chambers in a human heart.
The sharks heart has two chambers.
It has 3 chambers.