The Polleni Grouper, Cepholopholis polleni, also known as the Harlequin Hind, Harlequin Grouper, or Harlequin Rockcod, is a rare and beautiful species of grouper. It has a fantastically colored green, yellow, and sometimes purple body with yellow tipped fins. They are aggressive eaters and should not be housed with small fish or inverts. A tank of at least 100 gallons is best to house this fish. The Polleni Grouper is one of the more rare fish found in the aquarium trade. The Polleni Grouper will eat most meaty foods.