The name echinoderm is from Ancient Greek ἐχῖνος (ekhînos) 'hedgehog', and δέρμα (dérma) 'skin'. Echinoderms are
Historically, … See more

Echinoderms evolved from animals with bilateral symmetry. Although adult echinoderms possess pentaradial symmetry, their larvae are ciliated, free-swimming organisms with bilateral symmetry. Later, during met… See more

Many echinoderms have great powers of regeneration. Many species routinely autotomize and regenerate arms and viscera. Sea cucumbers often discharge parts of their internal organs if they perceive themselve… See more

Echinoderms become sexually mature after approximately two to three years, depending on the species and the environmental conditions. Almost all species have separate male and female sexes, … See more

Echinoderms are globally distributed in almost all depths, latitudes and environments in the ocean. Adults are mainly benthic, living on the seabed, whereas larvae are often pelagic, living as plankton in … See more