The infamous crown-of-thorns starfish grows to
over a foot across and has 10-20 arms. It is well known for its voracious
appetite for live hard-corals. At various times it has been blamed for the
killing of large portions of reefs in parts of the Pacific ocean,
including a large portion of the great barrier reef of Australia during
the 1960's. It is so despised that many scuba clubs organize "starfish
hunts" in which these starfish are rounded up in an effort to save reefs
from destruction. These starfish should be handled carefully, since the
long, sharp spines are mildly venomous and can inflict painful wounds
(slow to heal, too, as I can attest!).
One explanation for local
population explosions of these destructive starfish is the collection of
this starfish's natural enemy, the Triton Trumpet (Charonia
tritonis). For this reason trumpet shellfish (if alive) should
never be collected by divers and are often protected by law, because of
their importance to reef ecology.