Sea Urchins – What are Those Bizarre Creatures of The Sea?

Who has no brain, but manages to hitch a ride?

Sea Urchin!  – read on to learn more 🙂

Sea urchins are a group of spiny sea animals that are related to sand dollars and starfish. They can easily be mistaken for shells or rocks because of their hard, round, spiny bodies. They are often found in rocky areas of the sea from the very shallow water to the great depths.

Friend or Foe?

In Cyprus sea urchins can be found in the rocky shelves just underwater the water line. Be careful not to stand on them or you will have a nasty surprise. Predators who fail to heed the warning may end up with spines in their skin.


Sea urchins are primitive animals, but they boast a powerful defence mechanism. Their stings can be extremely painful and may cause extensive damage to the skin, tissue, and even bone.

The calcium-filled spines that a sting can leave behind can be difficult to remove from the skin. Prompt extraction of them, however, can prevent further injury.

Their spikes are such an effective weapon that carrier crabs are seen to carry a sea urchin on their backs as protection against predators. Great way for a sea urchin to hitch a ride to new feeding spot!

Watch this cool video of carrier crab (very adequate name) carrying a sea urchin on its back as a weapon.

Fast facts on sea urchin stings

  • Most sea urchin stings are a painful annoyance only.
  • The spines hurt when they enter the skin, as a large splinter would.
  • Anyone with a history of allergic reactions to stings or bites should get medical help after a sea urchin sting.
  • The only way to completely avoid a sea urchin sting is to stay out of the ocean.

Treatment of sea urchin stings

  • Vinegar may be used to treat sea urchin stings, as it will help to dissolve the stings trapped in the skin.
  • First aid for sea urchin stings requires prompt removal of the spiky spines.
  • Removing sea urchin spines with tweezers can cause them to break and splinter at the skin’s surface.
  • The spines might appear to be gone but can remain in the deeper layers of skin. Instead, it is advisable for a person to soak the affected area in vinegar. Vinegar can help dissolve the spines.
  • The spines are gone when they are no longer protruding from the skin, and there are no black or gray dots remaining at the surface of the skin.
  • If the first vinegar soak does not remove the spines, continue applying vinegar compresses several times a day until the spines are gone.
  • Warm compresses can help with pain and swelling. Nonsteroidal anti-inflammatory drugs, such as ibuprofen, can also relieve pain.
  • In the days following the injury, keep the wound clean and apply a triple antibiotic cream from the pharmacy. If the wound is red or itchy, topical hydrocortisone cream may help.
Sea Urchin
Image by AnjaStr from Pixabay

Interesting Facts about Sea Urchins

  1. They have no brain. Their mouth is under their body.
  2. Most creatures in the world consist of two symmetrical parts. Body of sea urchins consist of 5 symmetrical sections. Real weirdo of the ocean!
  3. There are more than 900 species of sea urchins.
  4. Their spines are light sensitive.
  5. Some types like Pacific purple sea urchin are used to prepare sushi.
  6. Most sea urchins are not dangerous, however few species have venomous spikes or bites.
  7. Some species of sea urchins may live 100 or even 200 years. Pretty awesome for such inconspicuous creature!
  8. They are very sensitive to water pollution.

Can We Eat Sea Urchins?

These echinoderms may not look too appetizing given their spiny exteriors, but they are prized around the world for their fishy-flavored roe and flesh.

Though they are often eaten raw, such as in sushi (typically called “uni”), some people prefer to eat them immediately after they are cut open. (No Thank You!).

Eating raw seafood comes with the risk of contamination with bacteria that can make you sick, so always ask your doctor before adding raw sea urchin to your diet. In restaurants or tavernas sea urchins are cooked, then eaten plain, or included in dishes such as pasta with white wine sauce or seafood stew.

sea urchin
Image by Gerhard G. from Pixabay

Don’t Kill or Catch Sea Urchins

What should you do when you find them where you swim?


Just avoid their spikes.

Please remember they are part of the ecosystem and they should be left alone. Sea urchins are one of the favourite foods of octopus, lobsters, trigger fish, wrasse and even sea otters.

We would love to hear from you!

Did you have any encounters with sea urchins ? Let us know in comments!

I hope you enjoyed reading this post.

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Sea Urchin
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