Echinodermata

    The members of this group only occur in seawater. They have a body plan that is arranged in a circular fashion with no distinct head end, tail end or left and right sides. Echinoderms have an outer covering that is made up of hard, chalky plates, and often covered with spines. They possess hollow, water-filled projections called tube feet with suction cups at the ends. The tube feet are connected to an internal water-vascular system and are used for attachment and movement. The mouth is located on the underside and the anus on the topside.

    Feeding methods vary between species. Sea stars feed on a variety of invertebrates, sea cucumbers feed on plankton or detritus, sea urchins feed on seaweeds, sessile invertebrates, and dead animals, and brittle stars eat detritus and smaller invertebrates.

    The sexes are separate and they release sperm and eggs into the water where fertilization takes  place. The fertilized eggs develop into free-swimming larvae which settle and develop into adults.

    The dried shells of sea stars, sea urchins, and sea dollars are frequently used as decorations. The soft internal organs of sea urchins can be eaten.

    Echinoderms are well known for their immense powers of regeneration. Sea stars are famous for their ability to replace lost or damaged arms. Sea cucumbers are also well known for their ability to eject internal organs when endangered and to regrow them later.

                    Northern Starfish                

    This sea star has five or six radiating arms. Its colour can be purple, red, orange, yellow, brown, or greenish. The tube feet are in four parallel rows on the underside of each of the arms. The outer "skin" is rough with many small spines. It can grow to be 80 cm across and is found in tidepools or the subtidal region. Sea stars crawl slowly over rocks and seaweed using their tube feet. They mostly feed on mussels and other molluscs.

Daisy Brittle Star

    The body of this animal has a central disc with five long, thin, radiating, and flexible arms. The disc measures up to 2 cm across, while the arms up to 7.5 cm long and bear small spines. It varies in colour from brownish-red to blue, green, or brown. The disc is mottled and the arms are banded. They are found hidden under rocks in tidepools in the lower shore region.

Green Sea Urchin

    The body is a hard spherical chalky shell which can grow up to 9 cm in diameter and is covered by bright green spines that can be up to 1 cm long, and long extendible tube feet. They are greenish-brown in colour and they are often attached to rocks just below low water mark. They feed on the larger seaweeds and are eaten by cod and other fish, sea stars, and sea birds.