Acropora coral are sometimes known as Staghorn coral because they can look like antlers and grow up to 6.6 feet (2m) tall. But because there are 368 different types, or species, of acropora coral, they have many different forms. They can look like plates or tables over 9.8 feet (3m) across, or like bushes with branches that look almost like a human hand. They are also the fastest-growing coral on the reef; they can grow 1.2 – 3.9 inches (3 – 10cm) per year. Because they grow so fast, they are often the most common coral on the reef and a very important reef builder.