Here’s a neat video, brought to us by the guys at Cubic Aquarium, showing the epic struggles of the chocolate chip starfish battling a Harlequin shrimp. The shrimp (Hymenocera elegans) usually works in pairs to capture a sea star, often flipping them over and injecting them with a toxin that causes paralysis in the starfish. The starfish doesn’t die after being gnawed on. In fact, the star will survive even if a few legs are eaten off. They will stay alive for several weeks and serve as a food source for the shrimp during that time, with the shrimp returning for leftovers time and time again.
The chocolate chip starfish (Protoreastor nodosus), which is not reef safe, is the common food source for Harlequin shrimp in the home aquarium. They are cheap, readily available, and are sometimes even free because an unsuspecting reef keeper purchases one thinking they are coral friendly. After the starfish eats a few of the reefers prized soft corals, they desperately try to rid themselves of the starfish. Seeking revenge, the reef keepers often donate them to the Harlequin shrimp owners, hoping that they get what’s coming.
Keep in mind though that chocolate chip starfish are not the food source of these shrimp in the wild. They come from different parts of the world, but do serve as a suitable substitute for feeding purposes.