Echinoderms Invertebrates Animal Kingdom. Wildlife. Fauna. Zoology.

General characters:

They are animals of radial symmetry, of soft body with rigid structure thanks to a skeleton composed of numerous calcareous plates, located under the epidermis. These plates have tiny spines that go outside giving the touch a spiny texture.

There are about 6,000 species and they are very different from the rest of the animals, their body is furrowed by an authentic system of water channels connected from the entrance with small suckers called "ambulacral feet" and "pedicelarios", which are used to move and capture their prey.

When these tubes are filled with water with pressure they become rigid; if they have no pressure, they are loose.

The echinoderms lack head and tail, their mouth is in the center of the lower pole and the anus, the excretory and reproductive holes, are located in the upper pole.

They have a great power of regeneration.

The senses are underdeveloped. They reproduce sexually although sometimes they also do it by excision or partition.

Classification of echinoderms.

• Crinoids
• Holoturioideos
• Asteroids
• Ofiuroideos
• Echinoids

Lírio de mar

Crinoids, called sea lilies due to their flower appearance, have their body with a central part in the shape of a calyx, a disc from which the feathery arms with large number of appendages and a peduncle or stem with which they are set to the seabed. In the central part of the disc is the mouth and aquifer or ambulatory channels that reach all the arms they use to capture small food particles. The comatulas only remain fixed in their juvenile phase and then crawl through the arms.

Asteroids

Asteroids or starfish have a starry or pentagonal shape.

From its central part, 5 to 45 arms are developed that have some mobility.

On its lower face is the ambulacral groove with two or four sets of ambulacral feet.

The skeleton is made up of articulated plates and spines and pedicels.

There are numerous tiny gills on the surface of the skin.

The mouth lacks a chewing organ. The stomach, in the form of a sac, can be projected outside to encompass its prey, on which it pours its digestive juices until it dies.

The intestine is branched with digestive glands and numerous blinds.

They feed basically on mollusks, which they manage to open by sucking their numerous ambulacral feet.

They have visual organs in the form of eye spots at the end of their arms.

Starfish have great regeneration power.

Holoturioideos

Holoturioids, called cohombros or sea cucumbers, are elongated and cylindrical echinoderms, generally soft in body.

The skeleton is not continuous, but composed of reduced or absent calcareous spicules.

The movement is done by five rows of pedicels or ambulacral feet along the body.

Around the mouth they have a crown of tentacles that are modified pedicels with nutritive function; excretory, excavator, etc.

They live buried in the sandy bottom. When they are persecuted, they can throw outside of their internal viscera that regenerate quickly again.

Ofiuroideos

The offices are quite different from asteroids or starfish.

They have a central disc from which five arms, long and thin, sometimes branched and with spines in some species, lacking ambulacral groove.

These arms are formed by rings with tentacles or palps with sensory cells.

The digestive system has a star-shaped mouth, without radial intestines and without anus.

They are enormously voracious and attack crustaceans, fish, mollusks, etc., constituting a plague on the seabed.

Sea urchins or echinoids

They are echinoderms of obvious radial symmetry, of generally spheroidal body, devoid of arms, with a calcareous skeleton of appearance and characteristics of a true shell or shell, provided with mobile spines, which, in some species, are poisonous.

In the skeleton there are five zones of double rows of plates, called ambulacral, with holes through which the ambulacral feet leave and another five rows of double plates, called interambulacral.

They have two poles: the anal and the buccal. In the anal is the motherboard, where the aquifer system flows.

They have pedicelarios with small tweezers to capture food.

The mouth is formed by a robust chewing device called Aristotle's flashlight, with five jaw pieces with teeth.



Other information about fauna in Aragón:

A small list of species in Aragon would be the following:

Vertebrates	Invertebrates
Mammals Red squirrel. Bear. Fox. Artiodactyl Ungulates Deer. Wild pig. Birds Classification of Birds Storks. Capercaillies. Reptiles Amphibians Urodelos.    Marbled Triton.    Webbed Triton.    Pyrenean triton. Anurans. Fishes	Metazoans Arthropods Myriapods Insects Arachnids Spiders Crustaceans Annelids Worm Molluscs Asquelmintos Platelmintos Celentereos Porifera Protozoa
images about the fauna in Aragon.    photographs on invertebrates.    beneficial animals for agriculture.



Also Aragon enjoys a diverse and varied Nature where passing by plants, animals, Geology, or landscapes we can arrive at a fantastic bestiary that lives in its monuments.

The information will not be complete without a stroll by its three provinces, with shutdown in some of its spectacular landscapes like Ordesa, the Moncayo, Monegros or by opposition the Ebro.

Also you can dedicarte to the intangible ones: from the legend compilation that also does to universal Aragon.