Tunicates are closely related to vertebrates like ourselves. They have a relatively simple body plan with two openings or siphons. Water enters their oral siphon and nutrients are absorbed in their digestive system. Tunicates are used to study several biological processes.
This is image show the oral siphon of a Botryllus schlosseri individual (known as zooid) that has been processed by immuno-fluoresence 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.