What are Cnidarians?

Cnidarians are a relatively simple phylum of animals (one of 38), which includes jellyfish, corals, sea pansies, sea pens, boxes and sea wasps. The phylum gets its name Cnidaria, from the Greek "Cnidos", which means "stabbing needle".

All Cnidarians, including stationary corals (builders of famous and beautiful coral reefs), have stabbing cells called cnidocytes that obtain their stings from organelles called nestatocysts (also called Cnidocytes or Cnidoblasts). It is believed that Cnidarians are among the most basic of all animals, with the exception of fungi and fossils dating to the Ediacaran period, 580 million years ago. Cnidarians left some of the first clearly identifiable animal fossils.

There are more than 10,000 types of Cnidarians, divided into four main classes: anthozoa (anemone, corals), rockozoa (real jellyfish), cubozoa (box jelly) and hydrozoa (Obelia, Aequorea, other war, others).They live in cells of other animals) and myxozoa, small fish/worm parasites. The classification of the last two groups in Cnidaria is relatively recent and has been made possible by genetic analysis.

Cnidarians have a reputation that they are beautiful but painful or even deadly. Every year thousands of people are frozen jellyfish, resulting in extreme pain for many and even several deaths. In Australia and other high -risk places, the beaches are fenced with nets to protect swimwear from painful CNIDARIAN touch. Particularly dangerous are boxing jelly and one species, Irukandji jellyfish, is considered one of the most toxic animals on the planet. One victim said, "I didn't think it was possible for someone to endure this level of pain without turning into vegetables."

Cnidarians (Coral) Make -Light Superorganism in the World, a large barrier cliff in Australia that covers an area of ​​about 344400 km (132 974 square miles). This cliff and many others around the world have grown for thousands of years as coral polyps were dying and left behind their skeletons and then set out to create new sections of the cliff. These cliffs are home to many sea animals, including majestic green sea turtles.