Common starfish, Echinaster sentus, are the classic starfish that most people think of when you mention starfish, mostly because that’s what you see dried out in shell shops and in the little epoxy trinkets that say “Welcome to Florida”. I included two starfish in the picture to give you an idea of the different colors that you might get, and there are a few other variations of red, brown, or orange. If handled properly along the way, these starfish can be very hardy and will live for a long time on your aquarium. They seem to like to crawl all over the walls of your tank as opposed to hiding under rocks, so they are a critter that will get a lot of attention. When they are near the top of the tank, they will take food that is placed near their tube feet, so they are kinda cool to feed. To my knowledge they don’t eat corals or most other invertebrates, but they might go after a small clam, scallop, or mussel, so I wouldn’t advise mixing the two.
This starfish can get up to about 7″ from arm tip to arm tip, but the ones we send are more like about 3 inches or more.