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Echinoderms

Echinoderms are exclusively marine bottom-dwelling animals, that is to say they are benthic animals (with very few exceptions). Their body has a radial symmetry in which the body is divided into five regions around a central disk. Another characteristic of this group of species is the presence of calcareous ossicles that form part of their skeleton. Inside the Echinoderms' skeleton we find a complex system of ducts and reservoirs filled with liquid that the specimens use thanks to the action of various muscles, to generate hydrostatic pressure and with it hydraulically actuate structures called ambulacral feet. These ambulacral feet can perform functions of locomotion, gas exchange and/or play a role in feeding or sensory perception. This vascular system is called the aquifer and is connected to the exterior through the madreporite or madreporic plate.

There are currently more than 7,000 described species of echinoderms, which are found in all oceans and seas regardless of depth. In fact, in the deepest abyssal plains, they are the most frequent animal group, representing up to 95% of the biomass of the abyssal ecosystem.

Echinoderms are a group of great ecological, biological and geological importance. At the ecological level, there is no other group of animals so abundant in the biotic deserts of the abyssal plains, as previously mentioned. Echinoderms are animals with a great capacity for tissue regeneration, in some cases it is possible to completely regenerate an individual from one of the five regions of its body. Therefore, this regenerative capacity is a feature of great interest for biology, and many species of Echinoderms have been used in regenerative studies. Geologically, the importance of Echinoderms is determined by their calcareous skeletons, as well as by their great abundance. This has made Echinoderms a major contributor to limestone deposit formations.

In relation to the reproduction of Echinoderms, their reproduction is mostly sexual and external, although there are species with asexual reproduction by fission of the specimen.



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