First off, you want to wait ideally several months before you put a starfish in a newly cycled tank. They are very sensitive to changes in a tank chemistry, and the tank needs months to settle down. Your specific gravity also needs to be about 1.025-1.026 for many of these animals.
How big is your tank?
Chocolate chip stars are a good choice for many tanks because they can be spot fed. Other stars can not be making them unsuitable for most except very large reef tanks (100+ gallons). BUT they can be fed because they are omnivores, and may eat things like snails, clams, scallops and other slow moving invertebrates. I tend to think it is unlikely they will eat shrimp, etc.