They eat algae and keep the chloroplasts for their own use.

They help keep the pond clean by eating algae and insects.

Down South they were worker fish, imported to clean up enclosed areas by eating algae.

In the summer they eat bugs and algae, a sort of natural cleanup committee for the pond.

He claimed the fish ate algae in the tank and did not need feeding every day.

It eats algae growing on the rocks in a stream.

They will not, however, generally eat plants or algae.

They get their food from the water, usually eating algae and other tiny creatures.

Some animals eat tiny algae which they scrape off the rocks.

I ate algae throughout the day until my stomach could take no more.