1. Sea urchins are echinoderms.
• Echinoderms are animals having radial symmetry body structure (spherical-shaped) which can only be found in the sea.
• It belongs to the same group as sea stars, sea cucumbers and sea lilies.
2. Sea urchins are often referred as the porcupine of the sea.
• They are considered among the wonders of the sea.
• They are also sometimes called sea hedgehogs.
• Their external body is covered with spikes and claw-like structures distributed over their long spines that serves as their weapon to debar their predators.
• These structures outlining their spines are also capable of camouflage to deceive villains wandering around.
3. Spring is the mating season of sea urchins.
• They reproduce by external fertilization, whereby millions of sperm and egg cells (gametes) are release in the water for union and fusion.
• Male urchins can release up to 10 billion sperm cells while female urchins releases a million of egg cells.
4. Sea urchins have a water vascular system.
• This is a common trait among echinoderms.
• They are sustained by water that serves as their circulatory system.
• This hydraulic system is used in their overall functioning like mobility, food ingestion and metabolism.
• With their water filled feet, they can in fact walk fast using those feet, their spines and even their teeth.
5. Sea urchins are omnivores.
• They feed on both animals and plants.
• Algae, sea weeds and decaying organic matters are usually their favorite dishes.
• On the other hand, their enemies are fish, crabs, sea otters and humans.
6. Sea urchins can be found throughout the world.
• These marine invertebrates which are countless in numbers thriving oceans all over the world.
• There are more than 200 species of sea urchins ranging from edible ones to venomous type.
• They play a recognizable role in balancing the aquatic ecosystem.
• Huge part of the aquatic environment will be overrun by uncontrolled growth of weeds and algae without these creatures feeding on them.
7. Sea urchins are of great value in Japanese cuisine diversity.
• It is one of the ingredients used in sushi preparation.
• One of Japan’s top delicacies is sea urchin dishes including sushi.
8. Certain species of sea urchins have venom.
• Looks can be deceiving. Some urchins are stunningly attractive and may look harmless.
• One of which are flower urchins (Toxopneuetes pileolus), abundant in the Indo-West Pacific Ocean region
• This type of urchin is the most venomous one capable of penetrating human skin and stinging venom from its pedicellariae – fanglike structure covering the blunt spikes all over their entire body
• The sting effect can either be localized or systemic.
• The victim may experience burning pain on the sting site. In severe stinging, respiratory distress may occur.
• In some cases (but very rare) venomous stings can be fatal.
9. Sea urchins have sharp teeth capable of drilling holes on rocks.
• They can literally chew on hard stones and still preserve their teeth which are actually self-sharpening ability of urchins.
• To drill bores on stones is their way to carve out den to keep away from predators.
• Sea urchins’ mouth is called “Aristotle’s lantern”, consists of five bony plates (sharp teeth) to engulf and churn their foods.
10. Sea urchins are creatures having the longest lifespan on earth.
• Scientists have found that some species can reach and survive for up to 200 years.
• Among these species is the Red sea urchin that inhabits on shallow coastal water.
• Based on the findings of the studies, its vast life span surpasses almost all terrestrial and marine animals.