The blue spot puffer isn't picky about what it eats. They can, however, attack the starfish if they become hungry. Coral reefs are eaten by starfish, which causes harm to the reef. Pufferfish are employed to keep starfish populations under check.  Starfish, on the other hand, are a good source of minerals for pufferfish. Pufferfish attack and eat starfish because they are starfish predators.