By: David Anderson

Structure of a Coral Each coral is lined with multiple polyps which are individual animals that make up the coral. Each polyp has 3 different layers in the structure. 1. Outer Epidermis 2. Inner layer of cells lining the gastrovascular cavity, which carries out digestion 3. Mesoglea- which lies in between the outer epidermis and inner layer. Each polyp contains a mouth in the center of surrounding tentacles. The tentacles contain a stinging cell that helps them bring in food which is called nematocyst. Polyps are very vulnerable and therefore have a calcium carbonate skeleton made that protects them. The base of all coral reefs are the calcium carbonate skeletons

Zooxanthellae Zooxanthellae are single celled algae use the sun to go through photosynthesis which creates nutrients for the polyps and there fore promoting coral health. Without zooxanthellae a coral would not be able to survive because though polyps can capture food it is not nearly enough energy produced that is needed for corals to live. Zooxanthellae and coral are an example of a symbiotic relationship; mutualism because they both benefit. The coral gets much needed nutrients and the algae gets a form of protection from the coral because it lives inside of it.

Types of Reefs

Fringing Reef Directly attached to the coast Grow on shelves of coastlines and are right along the edge of the water Type of reef found closest the shore Able to create lagoons right off the coast

Barrier Reef Grows parallel to the coast Separated from the coast by a large lagoon with great depths Best know is the Great Barrier Reef in Australia which is the largest reef in the world

Atoll Reef A circular reef surrounding an island The island has sunken under the waters surface

Patch Reef Small isolated reefs Can be combined with all 3 of the other reef systems

Symbiotic Relationships Within My Reef Aquarium

Clownfish and Anemone The clownfish and anemone mutualism relationship is by far the most well known symbiotic relationship in the ocean because of the movie Nemo. Since the release of the movie when I was young I have always been interested in the relationship between them. Both the species in the relationship benefit from the other. The clownfish gets protection from predators because anemones tentacles release a potent sting and few are up the fighting anemones. Anemones benefit because the clownfish acts as a house maid, will keep the anemone clean, and have also been documented feeding the anemone.

Pistol Shrimp and Goby In this less known symbiotic relationship a nearly blind pistol shrimp will pair with a keen eyed goby. It is a form of mutualism between the two. The pistol shrimp will burrow and the goby provides eyes on the job. The pistol shrimp benefits because it is nearly blind and only can see general shapes but the goby has very good eye sight so the shrimp will get the benefit of eye sight from the goby which it always has an antenna on and as soon as the goby flicks its tail the shrimp knows to go back into the burrow. The goby benefits because the shrimp digs in the sand and creates a safe home for the goby that protects it from predators.

Next PowerPoint: Coral Disease and Death…