Phylum Coelenterata or Cnidaria

Phylum Coelenterata or Cnidaria

Meaning:

The word cilentrata comes from the Greek word Koilos = Hollow; Enteron = Intestine is made up of. Its new name is Cnidaria, which is composed of Greek word Knide = Nettle or Stinging cell bearing. The term cilentrato was first used by Leukart in 1847 AD. There are approximately 9500 species in this union. These are low-level animals in multicellular organisms.The name Cnidaria has been given to this group of animals due to presence of special cells called Cnidocytes. These cells give rise to nematocyst the stinging cells characteristic of this group. The following are the major traits of the organisms of this union:

Occurence:

These water bodies are mostly marine, solitary or colonial animals.  So mostly found in marine water and few are found in fresh water like jelly fish, which is not a true fish because all the fishes are included in phylum chordates. It has only a name jelly fish due to its body structure.

General Characteristics:

These are the diploblastic creatures. The external level of the body is Ectoderm and the inner level is Endoderm or Gastrodermis. There is acellular mesoglyia (Mesoglea) between the two levels. The cells of the body are arranged at the tissue level.
These beasts are multicellular, in which only one cavity is found, which is called coelenteron.
Its head is a radial symmetry.
They do not have a head.
They do not have anus.
It is like a digestive cavity pouch.
In this, long-long contact (Tentacles) are found around the mouth.
Stem cells (Nematoeyst) are found in their contact and other parts of the body. Stem cells are absent in the tenophora.
There is no respiratory system, emission mechanism and circulatory system.
Among them, the branches of nerve cells together form the nerves of the nerves.
These can be found in eye point or statocyst.
Polypoid builds lipid bone called coral.
Alternation of generation or metagenesis is found in their life cycle. These are of two types - Polypoid and Medusoid.
Among these, asexual reproduction by budding is done by the sexual reproduction gametes.
Their larvae are mainly called plenula (planula).
The Division of Labor is found in their cells. That is, there are different cells for the editing of different tasks.
The action of respiration and emission comes from the surface of the body.
They lack the brain.
Examples: Hydra, Physalia, Obelia, Aurelia, sea anemone, Fungia, Meandra, Penatula, Gorgonia etc.

Important facts:

Hydra is found in the properties of immortality.
Aurelia is usually called a Jelly fish. Due to the development of Mesoglia, Aurelia's body looks like a very thick jelly.
Metridium is known as the sea-anemone.
Gorgonia is called Sea-fan and Penatula is called Sea Pen.
Physalia is generally called the Portuguese warship (because it looks like a reverse warship).
They range in size from microscopic (Hydra) to two meters in length (Hydrozoan polyp).

Polymorphism (Extra reading material):

"Coelenterate animals may show a number of zooids. They are of different forms. They take up different functions. This is called polymorphism". Polymorphism denotes division of labour among the zooids of the individuals called zooids. They are mainly two types:

(1) Medusae:

    The medusa is free swimming.

     It has umbrella shape.

     Its main function is Reproduction.

     It is represented by polyp form.

     It is converted into the polyp form through sexual process.

     For example: Obelia like animals show two forms. polyp nutritive zooid and medusa        

     reproductive zooid. This is called dimorphic organism.

1- Polyp:

    One of the two forms that take coelenterates (for example, a hydra or coral): usually adjacent with      a hollow cylindrical body with a tent ring around the mouth.
    In some species of collateral, polyps are a phase in the life cycle which is optional with a   
    pharmacological phase
    A small vascular development on the surface of a mucous membrane.
    The polyp form converted into the medusa form through asexual process.
    Its main function is feeding, food capturing and defense.

Observation:

A polyp in zoology is one of the two forms being found in the Phylum Cnidaria, being another medusa. Polyps are roughly cylindrical in shape and spread on the axis of the shape of the vase. In polyps alone, unbound endings are connected to the substrate through a disc-like holdfast called crazy disc, whereas in the colonies of Polyps it is directly or indirectly connected to other polyps. There is a mouth in the verbal end, and surrounded by a circle of tent.
Specific sticky form for a coelenterate. For jellyfish type which takes a temporary life. The body is cylindrical, and the tent is underlined around the mouth. The bottom end becomes a footboard, and it adheres to the bottom of the water in this part. Generally, coloretrate generates polyps from the remaining eggs due to the genital reproduction of jellyfish, and jellyfish is generated from the extraordinary emergence of polyps to replace the generations. Polopotype is only for Anthoid and Hydra. → jellyfish / coelenterate

Coral:

Marine colonial poles are characterized by a calcars skeleton; People in different sizes often make rocks
A dark pink average is a convertible color
Fertilizer lobster cry; Red color in cooking; Garnish or color is used as a sauce
The hard rock skeleton of a Mediterranean coral that contains delicate red or pink color and used for jewelry
A common word for such a type that creates Kalsurus skeletons with cave parasites. The eight existing coral species, the six radish are divided into coral. Hakusa coral polypept is characterized by eight tents and diaphragm, it is cylindrical, has been buried in co-meat to make the colony body. Below polyp's mouth, there is a stomach and a celloper which does not differentiate into the body of the cavity, and the mouth also acts as a discharge cavity. Fertilizers are usually done in seawater, the remaining eggs enter floating through floating plano larva in temporary life, after which they sprout. Coral, which is considered valuable as an ornament, has a secret limestone skeleton by the colony. Acasoo, Momoiro Coral, Shirosango are known, and they are growing in the ocean floor rocks on the coastal dozens of hundreds of meters of Shikoku of Taiwan near Taiwan, west of Kyushu, Ojaswada. Consolidated in the coral network, it is used for defeats, OB etc. The six-coral corals feature tent, the diaphragm consists of six or six tents. Ishjano, which make up the coral reefs, is included in it, and in the shallow ocean floor of the hot sea it has many different types. It is also known that the types of deep sea types which do not form Corals exist widely in the geological era since the Ordovician era, and many indicators are important as fossils.

The world's largest Coral Reef:

The world's largest mud-reef is the Great Barrier Reef (Australia).
Threaded structure is found near the mouth of the animals coming under this union. The main creatures under this union are Hydra, Jellyfish, C. Anemone and Muga etc.Coral reefs are found in West Indies, East coast of Africa, Australia and Island of Coral Sea.

Importance Of Cnidarians:

Coral reefs protect shores from erosion by tidal waves. Corals are used in jewellery and others are used in aquaria, rock gardens etc. Some cnidarians have poisonous stings e.g., jelly fish and sea anemone.