There is a certain kind of damsel fish, the Stegastes Nigrigans, which will actually selectively cultivate the algae they prefer to feed on. They have shown to actually encourage the growth of Polysiphonia, their preferred food, and limit the growth of other algae which they can’t digest as well. Researchers, which are writing in the open access journal BMC Evolutionary Biology, have been investigating the algae preferences of damselfish and explore their intricate cultivating practices all across the Indo-West Pacific region.

Hiroki Hata from Ehime University, Japan, worked with a team of researchers to explore this ‘gardening’ behavior. He said, “We surveyed 320 territories of 18 damselfish species and thoroughly examined algae from each fish territory from coral reefs in Egypt, Kenya, Mauritius, the Maldives, Thailand, Borneo, the Okinawa Islands, and the Great Barrier Reef. We found that although the crop alga species shifted in the West Indian Ocean, the intensive farming by damselfish was seen throughout this geographic range”.

It has been found that damselfish do not posses any organs which would allow them to process cellulose fibers, and they aren’t able to digest many species of algae. The most common type of algae they feed on is the red algae known as Polysiphonia. Unfortunately, this kind of algae is not very competitive and the damselfish lend a helping hand by killing off competing algae.