Ascidians are marine animals closely related to vertebrates like us. B. schlosseri is a colonial ascidian that has an extracorporeal vasculature, meaning that their blood vessels are outside of their bodies. These blood vessels are used to study new vessels formation, cancer, and aging. This is image shows a blood vessel of the extracorporeal vasculature of the colonial ascidian Botryllus schlosseri that has been processed by immuno-fluorescence to show the proteins Cadherin (in green), Actin (in red) and the nuclei of the cells are stained with the dye DAPI (blue). The image was acquired using confocal microscopy.