So that the sea urchin can protect itself from is enemies, it also has venomous spines. They also use their spines to kill other sea ceatures, so they can eat them.
they are venomous
its sharp spines
Sea urchins do NOT shoot there spines. They can simply let them pop out (sort of like a porcupine). Most people make this mistake... neither a porcupine or sea urchin SHOOT there spines. They do harden and stick out farther but they DO NOT SHOOT THEM!
No. Not even close. Sea urchins are small, herbiverous marine invertebrates with spines.
A sea urchin's body is covered in sharp spines.
sea anemones have stinging tentacles, and sea urchins have spines.
So that the sea urchin can protect itself from is enemies, it also has venomous spines. They also use their spines to kill other sea ceatures, so they can eat them.
they have spines that react to predators
Mostly for protection and also for locomotion.
Sea Otters find sea urchins on the ocean floor and break it open with a rock. It will then eat everything except the spines (the insides).
Sea urchins are covered almost entirely with spines, except for the bottom of their body.
A sea urchin is covered with very long, quite sharp spines. I know a scuba diver who banged one with his knee and had to go in for surgery.