Sea urchin

The sea urchin is a member of the echinoderm family of sea creatures, found in oceans all over the world. Their shell is densely covered with long sharp spines which are often poisonous. These spines serve both to protect the urchin from predators, and to paralyse their prey[?].

At first glance a sea urchin often appears to be an inanimate object, or one which is incapable of moving. A sea urchin has no visible eyes, legs or means of propulsion, but it can move freely around the ocean floor by progressively waving its flexible spines and 'walking' on them.

Some sea urchins have large thick spines, others are covered in a myriad of extremely long thin spines that are as fine as hairs, and some have short blunt spines.

Sea urchin is one of the favorite foods of sea otters[?]. Recently the population of sea otters in the Monterey Bay of California has diminished. As a result, the population of sea urchins have multiplied and they are chewing up the kelp forest in the area and upsetting the eco-system.

Raw sea urchin is a popular food in Korean cuisine. Sea urchin, or uni, is also popular in Japan's sushi cuisine.

A sea urchin with very large thick spines

A much spinier sea urchin as a contrast