Venom Bomb

Venom Bomb

Nemo touched the Butt.  But can he touch a spiky urchin?

This is Sandra Tsing Loh with the Loh Down on Science.

Fight or flee? When the enemy is near animals have to choose - and fast! Quick reactions and high-speed are great for escape. But slow moving creatures, like sea urchins gotta fight!

Just ask Hannah Sheppard-Brennand from Southern Cross University in Australia. She studies sea urchin self-defense.

All sea urchin species have jaw-like pincers called pedicellariae to fend off attackers. Some can even be venomous - like the ones on the collector urchin!

But unlike other urchins, the collector urchin doesn’t keep its weapons attached. When threatened by predators, it launches hundreds of pedicellariae! The explosion creates a cloud of venomous, floating pincers ready to bite the attacker. Sheppard-Brennand found that the venom bomb scares away a hungry fish BEFORE it attacks.   

This advanced weapons system helps the collector urchin stay safe in enemy territory. That way it doesn’t have to spend its life hiding and competing for food. This may be why their populations can boom in reef habitats.

Nemo beware! This urchin is collecting trophies!

Listen now.