Sponges are a source of food for many species of fish, and like sponges, they are attached to the ocean floor. Given these facts, what organisms are a source of food for many species of fish among the following options:
- remains of prehistoric life
 - whales
 - organic matter
 - sharks
 - gastropod shells
 - those on the ocean floor
 - Something made from fermented ricce
 - humans


 

      those on the ocean floor   