The name echinoderm is from Ancient Greek ἐχῖνος (ekhînos) 'hedgehog', and δέρμα (dérma) 'skin'. Echinoderms are bilaterians, meaning that their ancestors were mirror-symmetric. Among the bilaterians, they … 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 themselves to be threatened, regenerating them … 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 … See more

Echinoderms are numerous invertebrates whose adults play an important role in benthic ecosystems, while the larvae are a major component of the plankton. Among the ecological roles … 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 metamorphosis, the left side of the … See more

Sexual reproduction
Echinoderms become sexually mature after approximately two to three years, depending on the species and the environmental … See more

Locomotion
Echinoderms primarily use their tube feet to move about, though some sea urchins also use their spines. The tube feet typically have a tip … See more