They’re not related to legumes, but some of these animals release toxic saponins to complement their lackluster immune system. After birth, these animals develop well-defined limbs between the bipinnaria and brachiolaria developmental stages. Millions of these animals involuntarily shed their limbs and disintegrated due to a mysterious wasting disease. Mussel populations on North America’s Pacific coast are controlled by a purple type of these animals in genus Pisaster. The giant triton snail is ecologically important because it acts as the primary predator of a coral-eating species of these animals named for the crown-of-thorns. These animals are found in class Asteroidea, unlike their closely related “brittle” sister class. For 10 points, identify these echinoderms named for their five arms. ■END■
ANSWER: sea stars [or starfish; accept Asteroidea or asteroids until read; accept specific sea stars like the crown of thorns, purple, or common sea stars; accept sea cucumbers until “bipinnaria” is read; prompt on echinodermata until read; reject “brittle stars”]
<Biology>
= Average correct buzz position