- Sea urchins live on the ocean floor – they can be found in all climates, from warm seas to polar oceans – usually on hard surfaces, and use the tube feet or spines to move about
- Sea urchins have a round shaped body with long spines
- Urchins typically range in size from 3 to 10 cm (1 to 4 in)
- The mouth of the sea urchin is found in the middle on the underside of the sea urchin’s body. It is surrounded by lips of softer tissue, with numerous small, embedded bony pieces
- The sea urchin mainly feeds on algae on the coral and rocks, but can feed on sea cucumbers and a wide range of invertebrates also
- Sea urchins move slowly, crawling with their tube feet in a similar way to starfish
- The name “urchin” is an old word for hedgehog, which sea urchins resemble
- Adult sea urchins are usually well protected against most predators by their strong and sharp spines, which can be venomous in some species
- The gonads of both male and female sea urchins, usually called sea urchin roe or corals, are culinary delicacies in many parts of the world.
- The red sea urchin is the longest living creature on earth, with some living more than 200 years
