Starfish, Pacific Northwest
The sea urchin is found across the ocean floors worldwide. Sea urchins are commonly found along the rocky ocean floor in both shallow and deeper water and sea urchins are also commonly found inhabiting coral reefs. They can be found everywhere on the shores of the Pacific Northwest.
There are nearly 200 different species of sea urchins and they come in all shapes and sizes. Some sea urchins are covered in long thin spikes where others have a hard shell that is made up of chalky plates. The red sea urchin lives for up to 200 years,making it the longest living animal in the world.
They are omnivorous animals and will eat both plant and animal matter although they mainly feed on algae that grows on the shoreline rocks, they also feed on dead fish, mussels, sponges and barnacles.
They are preyed about by many predators that inhabit their marine environment, but also those animals that don’t. The main predators of the sea urchin are crabs, fish, sea otters, seals, birds and humans.
They have five rows of small tube feet which have suckers to help the sea urchin move about, capture food, and to hold onto the ocean floor.
They also have little claw like structure among their spines which the sea urchin uses for protection. These structures are small stinging structures that are not only used for defense but are also vital in keeping the body of the sea urchin clean.
The mouth of the sea urchin is found on the underside of the sea urchin’s body and has five tooth like plates for feeding.
Sea urchins spawn during the spring with the female sea urchin releasing millions of tiny eggs into the water that are then fertilized with the sperm of the male sea urchin. The tiny sea urchin eggs become part of the plankton and the sea urchin larvae do not hatch for several months. The sea urchin young will not become large enough to retreat from the plankton and down to the ocean floor until they are between 2 and 5 years old.