Cnidaria

Cnidaria are sea anemones, hydra, jelly fish and coral animals. Cnidaria are carnivores, meaning that they eat only other animals. They also have radial symmetry. This means that these creatures, if cut in half in any way dividing the cnidaria into two equal parts, each half would be exactly the same as the other. Cnidaria also have tentacles to help them catch their meals. All cnidaria also contain cnidocytes to sting thier prey.

The vast majority of cnidaria's do not have any type of sensory adaptations of any sort, or a brain. Some have basis sensing structures such as light, which allows for these creatures to migrate.

Every single cnidarian posses tentacles, which are used to both capture prey and as a weopon for self defence. The tentacle is spring- like that uncoils when ready to attack. The venom in the stinger paralyzes the prey, ready for the cnidarian to feast.

Some cnidarians are able to move around, such as the jellyfish. Jellyfish can "swim", meaning they open and close thier body to move around in their environment. Although the jellyfish is able to move around and swim for itself, the water currents most control the location of the organism.

Cnidarians do not contain an excretory system because "the metabolic waste that they produce is able to diffuse out of the cnidarians into the water that surrounds them" (shsapbiop2).

Cnidarians are only two layers thick, and all the cells in their body are right next to the water around them. The circulation system is then not needed, becausae the nurtrients are in contact with the environment.

Because all cnidarians arer able to sting, they are all able to protect themselves with their tentacles.

For osmotic balance, because there is no excretory system, osmosis is not regulated.

As stated before, cnidarians cells are in direct contact with the environment around them, and therefore the environment controls the animals temperature. Whatever temperature the surrounding environment is, the cnidarian are the same temperature.

Cnidarians are able to reproduce asexually and sexually. For asexual reproduction, either the offspring is produced when tiny pieces of tissue break off from the parent or when the parent splits into two, either lengthwise or crosswise. For sexual reproduction, cnidarians do not actually contain organs, but they can carry eggs and sperm. The female carries her eggs either in her stomach or her mouth, and when the male releases a sperm into the water, and the sperm comes in contact with the eggs, the eggs are then fertalized. The larvae are fist stored in the females stomach, and after a while are seperated from the mother. The larvae attaches itself onto something, and begins growgin into a polyps, and later into a colony. These colonies can become huge.