Crown-of-Thorns: The Venomous Giant Starfish Threatening Coral Reefs
Crown-of-thorns starfish are large, venomous sea stars with up to 21 spines that can reach 80 cm; their toxins can cause severe pain and, in rare cases, fatal reactions. More pressingly, they voraciously eat hard coral—up to about 10 square meters per starfish per year—threatening reefs like the Great Barrier Reef and capable of wiping out reef sections in weeks when populations surge. They regrow from fragments, making culling ineffective, so management favors injections of vinegar or bile salts. Natural predators such as giant triton snails and many reef fish help limit outbreaks, and the presence of giant tritons can even drive COTS away. They feed by everting their stomachs to digest coral tissue, turning it into a coral soup before retracting it.
