Stegastes nigricans

S. nigricans practices a form of cultivation on a species of red algae. The fish will claim a patch of "brown carpet" algae which it defends by chasing other fish and sea urchins away from. The fish also pulls up other bits of algae that attempt to grow in the patch and swims outside of its territory to spit the invading algae out. When the fish claiming a patch it removed, the patch is eaten up within a few days. When a patch of the "brown carpet" algae is caged to keep both S. nigricans and other fish out of the patch, other species of algae quickly overwhelm the patch. This seems to indicate that the "brown carpet" algae is dependent on S. nigricans for its survival.

References