Starfish are eaten by sharks that live near the bottom of the ocean, such as nurse sharks, horn sharks and Port Jackson sharks. They are also preyed upon by manta rays, Alaskan king crabs and other starfish.
Sharks eat starfish by crushing the hard outer skeleton with their teeth and eating the soft flesh inside. Sharks typically prefer eating prey such as squid because starfish don't contain as much meat. Manta rays sometimes eat starfish, but they do not consume starfish on purpose. Because a manta ray has no teeth, the animal eats by using its mouth as a sieve as it swims. This means that they generally eat any food that happens to get sucked up in the process. The manta ray's food of choice is plankton, which they typically search for near coral reefs. The starfish are eaten because they live in the same habitat.
Alaskan king crabs eat starfish by tearing them apart and consuming the pieces. The starfish typically regenerates lost limbs if the main portion of its body remains intact. Large starfish often prey upon smaller starfish if there are no other sources of food. They consume their prey by clutching them against the underside of their body where their stomach is located. The stomach then emerges from the body and engulfs the prey whole.