We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Starfish: one of the best known echinoderms

What they are - definition

The echinoderms are the beings of the phylum Echinodermata (echinos, thorn; derma, skin), usually found at great depths.

Summary of the main features of the echinoderms:

They are free-living marine animals, except for the crinoids that live fixed to the rocky substrate (sessile) and with radial symmetry that also contains their exception: the sea feathers, which move around the cumin.

As an example, we can cite the echinoderms: starfish, holoturia and sea urchin. This phylum appeared in the recent Cambrian period and has about 7,000 living and 13,000 extinct species.

Counting on Concentricycloideas, the currently living species of this phylum fall into the following classification:

- Echinoidea (sea urchin and beach crackers)

- Asteroidea or asteroids (starfish)

- Concentricycloidea, noted for its unique vascular system; two species; recently separated from Asteroids.

- Ophiuroidea (ofiuro)

- Holothurioidea (holoturia or sea cucumber)

- Crinoid (sea lily)

Echinodermal Nervous System

These living things have a fairly simple central nervous system, with a limited nervous network, whose neurons are not connected to the central organs. Although they have no brain, some animals of this phylum have ganglia.


Although they have different sexes, these beings reproduce without physical contact, that is, their reproduction occurs through the release of egg and sperm into the water, so fertilization occurs externally.


Many echinoderms have an extraordinary capacity for regeneration, such as the starfish, which when cut in many parts, is able to regenerate after a few months.

Biological curiosity:

Echinodermata It is the largest animal phylum that has no representation in freshwater or terrestrial life.

Sea urchin: another example of echinoderm animal.


  1. Meztigar

    that we would do without your brilliant idea

  2. Benicio

    I would like to encourage you to visit a site that has a lot of information on the subject that interests you.

  3. Neramar

    Congratulations, this thought just got you by the way

  4. Kakora

    Bravo, your idea is useful

Write a message