The crown-of-thorns starfish (Acanthaster planci) is a starfish with thorn-like spines sprouting all over its body for protection. These echinoderms grow to a diameter of up to 40 cm across and have 12 to 19 arms extending from their center. They are the largest starfish in the world.
Crown-of-thorns starfishIf accidentally touched or stepped on by humans, the starfish's long spines (which release a neurotoxin) are capable of pricking and stinging, inflicting great pain that can last for hours, as well as nausea and vomiting. Frequently, the area around the puncture turns a dark blue (erythema) and begins to swell (edema). The swelling may persist for a number of days or weeks. If you are pricked by a crown of thorns, it is important to ensure any remnants of the spine are completely removed.
Crown-of-thorns starfish are found on coral reefs in the tropics ranging from the Red Sea, throughout the Indian and Pacific Oceans, and all the way to the Pacific coast of Panama.
The starfish is a coral reef predator (a corallivore) and preys on the coral polyps by climbing onto them, extruding its stomach over them, and releasing digestive enzymes to then absorb the liquefied tissue. They feed alone at night, maintaining a constant distance between themselves and other crown-of-thorns starfish. During times of food shortage, these creatures can live on their energy reserves for over six months