You won't get two stars. You will either get 1 or none.
As a general rule of thumb with brittle and serpent stars, the way they move requires them to have at least a good portion of 3 legs attached to the body to be able to eat and survive. If you cut most species, you end up with one half with 2 legs and one half with 3 legs. If the star was healthy prior to the surgery the 3 legged piece may regenerate. The two legged piece stands no chance at all. It will waste away over the course of a few weeks.
Some species do have 6 legs, which is sometimes an indication that they will split on their own. In this case it's best to let them handle it themselves since they will do it when they're sufficiently healthy. If you decide to help them along and hack them up prior to that you're not likely to be cutting up a star in optimal health (so success is less likely).
Bottom line is it's a good way to kill animals. It's generally not a good idea with true stars either.
Well, I'm glad I asked first. Now I feel stupid, like what was I doing? going to frag it. what was I thinking?
