Question

The crown-of-thorns sea star, acanthaster planci, preys on the flesh of live coral. if coral animals are attacked by these sea stars, then what actually provides nutrition to the sea star, and which chemical (besides the toxin within their nematocysts) do the corals rely on for protection?

Answer 1

Answer – polyps; calcium carbonate

As explained in the question, the crown-of-thorns sea star, Acanthaster planci, preys on the flesh of live coral. While coral animals are attacked by these sea stars, POLYPS provides nutrition to the sea star. Corals rely on CALCIUM CARBONATE for protection (besides the toxin within their nematocysts).