Crown-of-thorns sea star and its nemesis
Crown-of-thorns sea stars (Acanthaster planci) feed on coral and, because of this, are considered a menace to the health of coral reefs. Up to a foot-and-a-half across, they can have as many as 19 arms and are covered by venomous spines. If this all sounds like this creature is a nasty piece of work, the good news is that it has not caused extensive damage to the reefs here in Hawaii.
The crown-of-thorns does have predators, one of which is triton’s trumpet (Charonia tritonis). These large triton snails, up to 20 inches long, feed on echinoderms including crown-of-thorns sea stars. When they scent prey, they will take off after it and are considered speedy for a snail. When a triton’s trumpet catches its prey, it grips it with its foot and applies saliva that causes paralysis, which allows the snail to consume its meal without further drama.