Question

Titan triggerfish feed on coral, which is often buried under rocks on the sea floor. To access the coral, these fish turn over rocks. It has been shown that the absence of the titan triggerfish changes the population levels of other species of fish that live in the same coral-reef environment.

One can conclude that the
are benefited by the
. The triggerfish are
.

Answer 1

One can conclude that the other species of fish are benefited by the triggerfish’s rock‑turning behavior. The triggerfish are a keystone species (an ecosystem engineer).