Sea Anemones & Coral (cnidarians)
Habitat
Sea Anemone and Coral live on the ocean floors all over the world. The water they live in is mostly clean because they can't survive in dirty water. Most live in group and serve as a great place to live for fish and other ocean animals. A great example of where Coral lives are the Great Barrier Reef. Here they provide a home for many ocean animals such as fist. Sea Anemone and Coral also eat some of the small fish. When fish pass by they attack their prey with one of their tentacles. Because Sea Anemone and Coral eat meat, they are considered carnivores.
Importance
Sea Anemone and Coral are very important to humans and our environment. They provide shelter for other animals to live in. It serves as a great home for many animals. They also trap the harmful fish with their tentacles. Humans use the skeletons of coral to build buildings. We also use coral to make jewelry. Coral reefs also are a great place to visit. They are very pretty and are fun to learn about.
Cool Facts
Sea Anemone and Coral are very unique animals. The skeleton that they produce is very strong. It's so strong, that it allows us to build things out of it. Coral is also unique because we have coral reefs that we can actually go see and explore. They are full of lots of information and are very colorful. Sea Anemone and Coral also have some unique things about their body parts. They carry a sac that is full of poison. They use this to kill their food and digest it. They also can produce a light with their tentacle to shock their prey. By doing this, they can scare their prey by blinding them.
Skeletal System
Sea Anemone and Coral may or may not have a skeleton system. The skeleton can either be inside the body or on the outside. They ones that don't have a skeleton are soft bodied. They get support form the other coral or sea anemone in the colony. They ones that have an external skeleton, produce chemical called calcium carbonate. This is what makes the skeleton so hard, and this allows humans to use it for building. The sea anemone and coral that have an internal skeleton produce calcium carbonate and another chemical called gorgonin. These chemicals are produced in the body wall.
Reproduction
Sea Anemone and coral can reproduce both sexually and asexually. For both these animals it is hard to tell if it is a male or a female. They can reproduce either inside or out side of the body. The life cycle of sea anemone and coral is very simple. They start off as a free-living larva and then turn into a polyp. They spend most of their lives as a polyp.
Eating
Anemone and coral eat their food in a unique way. They have a sac of poison that they use to kill their prey. They sting their prey with one of their tentacle. Then the food goes into the coelenteron or its stomach. These animals have a complete digestive system. This means it is similar to humans.
Waste
The only way a cnidarian can get rid of waste is by expelling from the mouth. This might seem weird, but these creatures eat from the anus. The reason that these animals do is because of these animals gastrovasular cavity.
Circulatory System
Although many animals have a circulatory system, these animals don't. The reason for this is because they don't need one. They don't need one because their cells are on the outside. this makes it easier for the animal to get the cells to keep on direct contact with water.
Examples
Some examples of this group are a sea anemone, coral, and Hydra. Each one near the ground of the ocean. Sea anemone and coral are near the ground. Hydra is a creature that is close by to the ground.
Nervous System
The nervous system of corals and sea anemones are simple nerve nets. They have cells on their body that detects light. They have something that is called stat cysts which tells them which way is up. They grow so that their entire body is underwater.
Sea anemones and coral have a very interesting excretory system. They get rid of pee and other waste by ejecting it out of their mouths. They also have some special holes in their body's wall that also expel waste.