The Sharp, 2 Centimetre-Long Thorns of the Crown-Of-Thorns Sea Star

Multiple Choice

The sharp, 2 centimetre-long thorns of the crown-of-thorns sea star are its spines. These spines, unlike those of most other sea stars, contain a potent toxin. If it were discovered that crown-of-thorns sea stars do not make this toxin themselves, then the most likely alternative would be that this toxin is ________.

A) derived from the nematocysts of its prey
B) absorbed from the surrounding seawater
C) an endotoxin of cellulose-digesting bacteria that inhabit the sea star's digestive glands
D) injected into individual thorns by mutualistic corals which live on the aboral surfaces of these sea stars