Some coral is extremely hard--with a skeleton made of stone. Some coral is extremely soft--so soft, it sways in the ocean current. Most coral animals are extremely small--the size of a pencil eraser. But some coral reefs are extremely large--bigger than New Mexico Tiny coral animals can build huge reefs, and most living things in the world's warm seas depend on those reefs to survive. Giant manta rays and tiny shrimp, bright parrot fish and snakelike moray eels all need coral reefs for food and shelter. Dive into Extreme Coral Reef Q&A to find out how important these beautiful structures are to life in the ocean.