I'm not really sure -- I have never put my cyano under the microscope! I can tell you that these hares are often found in silty waters, so a tank that has atleast an area that includes some "miracle mud" with some sand over top might be advisable. But these hares are often collected this time of year when they are breeding in the shallows -- something they often do before coming to the end of their (often short) lives. So winter months are not always the best time to purchase sea hares -- or if you do purchase them, do not be surprised if the hare does not live long in your system.