Cnidaria Phylum facts
* Cnidaria are diverse in form, but share stinging cells called nematocysts.
* Cnidarians are united because of the fact that their nematocysts have been inherited from a single common ancestor.
* Casually touching many cnidarians will make it clear how they got their name when their nematocysts eject barbed threads tipped with poison.
* Many thousands of cnidarian species live in the world's oceans, from the tropics to the poles, from the surface to the bottom. Some even burrow. A smaller number of species are found in rivers and fresh water lakes.
* Cnidarians are united because of the fact that their nematocysts have been inherited from a single common ancestor.
* Casually touching many cnidarians will make it clear how they got their name when their nematocysts eject barbed threads tipped with poison.
* Many thousands of cnidarian species live in the world's oceans, from the tropics to the poles, from the surface to the bottom. Some even burrow. A smaller number of species are found in rivers and fresh water lakes.
Digestive System
* Cnidarians have a one way digestive system. This means that undigested food and digested food are passed through the same place. This one way digestive tract is called the Gastrovascular Cavity. Cnidarians are predators who use many different nematocysts to puncture and entrap their prey. These nematocysts inject a toxic chemical which stuns or kills their pray. Once captured, food is passed into the Gastrovascular Cavity .