Examples of cnidarians

Cnidaria

When we speak of coelenterate animals we can refer to cnidarians , which have stinging cells and usually live in colonies, plankton communities or at the bottom of the sea.

They present a radiated symmetry and are characterized by having only one gastrovascular cavity with an exit to the outside, which has a double function, of anus and mouth at the same time; stinging cells on the outside of your body can itch on contact with our skin.

In total, the living beings within this classification are aquatic, and to a large extent marine. They have a variable number of tentacles around their mouth . They do not have a circulatory , respiratory or excretory system.

The functions required biologically by these living beings are covered by their gastrovascular cavity and the ectodermis. In its ectodermis there are different classes of cells, such as basal cells, sensory cells, and neurons.

Within the constitution of your body we can also find the gastrodermis and the mesoglea. There are more than 10,000 species of cnidarians ; some of them like polyps lack organs or limbs to support their body.

In this phylum we can also find several classes such as scyphozoa, hydrozoa, cubozoa and anthozoa. The oldest cnidarians are said to be anthozoans and the rest of the classes were derived from them.

Characteristics

We can find within this group jellyfish, anemones and hydras.
They have two layers of cells: the inner one called endoderm, and the outer one called ectoderm.
Taking into account the reproductive aspect of this group, we can establish that some of them reproduce sexually and some asexually , through what is known as budding.
In some cases, its reproduction evolves from the case of the polyp where it alternates from an asexual position to the jellyfish phase where it reproduces sexually.
Those of the hydrozoan type are characterized by alternating the polyp phase with the jellyfish during the entire extension of their life.
The antozoos are recognized as corals and anemones. They are polyp-shaped and have a kind of pharynx that in turn is divided into several well-defined parts.
The section of the scifozoos are the calls jellyfish.