The Echinoid Directory

Lifestyle - regular echinoids

Regular echinoids are almost exclusively epifaunal, living on the surface of the sea floor. A few species bore into rock surfaces thereby excavating themselves a home, and in some cases may even become trapped inside their burrow as they grow. Very few species can tolerate exposure at low tide, even for a short time. Regular echinoids feed using their lantern, rasping encrusting plants and algae from hard substrates or grazing on plants and sessile organisms such as sponges. Spines are used for defence and for locomotion, while the tube-feet are used primarily for adhesion, manipulation of larger particles, and for respiration. Although there are some species that are short-lived, surviving for only about a year, many live much longer, and some can reach as much as 15 or more years. They reproduce by shedding eggs and sperm into the water column. The sexes are separate but can rarely be distinguished from external appearance.
Regular echinoids can be keystone taxa in shallow marine communities as one of the dominant algal grazers. When populations have been lost through disease or overfishing, algal stands thrive and the nature of the sea floor can become drastically altered. Regular echinoids have many predators, including species of fish, sea otters, birds and crabs.