well, you could try at ur own risk, but a sea apple, and depending on how mature your tank is and how much lr you have, the pink and black cuke, rainbow urchins, red or orange serpent stars, pistol shrimp, bumblebee snail, the mouse cowrie, chestnut cowrie the keyhole limpet, tiger cowrie, tunicates or sea squirts. Also you could try the harlequin shrimp, but they need starfish for food, and so you would need two starfish, one you would put in a sump, the other in the main tank, after a week switch them so that one gets eaten and one heals ( this shrimp i would not recommend because of the pain inflicted on the star), sponges, gorgonians. You will not be able to keep all of these in your tank, you will have to choose which ones you want.