Three virtual sections through 3D models of a 72 hpf embryo (A) and 16 mm fish (B), showing the heart. Multiple virtual sections can be cut from the same 3D reconstructed model. The red lines show the positions of the sections relative to each other. Because of the 3D nature of the data individual structures can be easily located and viewed from multiple angles. The development of an individual organ or structure can be followed through the series of 3D models. In this case the sections are centred on the cardiac ventricle.