by: Hope Lee
The Two Types of Coral
Coral Reefs are living communities in the ocean. Hard Corals are rocks made up of animal skeletons. Fish who live in this type of coral swim with the tide, whether it's high or low. Most sea animals like fish or sea cucumbers live in Hard Corals. The animals live in,out,or by these chains of rock. Soft Coral are made out of Coral Polyps. The polyps are split into two groups also. The first group does not have a skeleton. Some of them do have tiny limestone needles called spicules. The other group has skeletons. Polyps hide inside their skeletons during the day but come out at night to feed. All polyps either way, are related to anemones and jellyfish.
This polyp does not have a skeleton.
This is a staghorn coral, because of its shape.
The coral has released a cell from their tissues which shows their white skeletons.
About Coral Reefs
The biggest coral reef is the Great Barrier Reef. Made up of almost 3,000 coral reefs and islands, it covers over more than 350,000 sq. km, which is bigger than Great Britain and half the size of Texas. The corals don't live forever, so in order to reproduce, the female egg form one coral and the male sperm from another will join together to create a new polyp, this is called Sexual Reproduction. Asexual Reproduction is an adult coral splits into two new polyps. Sea creatures like starfish do this. Even though the corals can reproduce, they can die out after decades or even centuries. When the corals are "bleached", the polyps inside release a cell form from their tissues which shows their white skeleton(if they have one). Polyps attach to a solid substrate and form colonies, staying there for life. Since the corals don't have brains, they have a nerve system called a nerve net that expands from its mouth to tentacles.