part of develops from start stage end stage cardiac ventricle TAO:0000009 Cavitated compound organ that receives blood flow from the atrium and delivers blood to the body via the aorta. Valves are present to direct flow. There are only two chambers present in the fish heart. zebrafish_anatomy ventricle ZFA:0000009 heart cavitated compound organ presumptive cardiac ventricle heart tube pharyngula:high-pec adult