Given the question: Fact 1: Sponges are a source of food for many species of fish. Fact 2: Sponges are also keystone species. Given the two facts above, answer the question "What are a source of food for many fish species?" with the following options: - layers of fat - bird species - human species - keystone species - Organic compounds - barnacles - gastropod shells - species of deer
The answer is:
keystone species