no harlequin shrimp will not eat them they will fight with them over thier kill and also will want to eat them when they are hugery, but no they will not eat them. they wont eat serpent stars either. The reason is they eat tube feet although n=mine eat the whole body, but they have never messed with my serpent or bristles. they will only eat stars with tube feet and if they get real hungery they will eat sea urchents. good luck