© Griffith University
Longfin damselfish (
Stegastes diencaeus) are known to aggressively defend the farms they rely on for food - but not, it seems, against planktonic mysid shrimps (
Mysidium integrum).
"We found that the damselfish keep swarms of mysid shrimps within their farms, providing them with a long-term safe haven from predators," says Rohan Booker from Australia's Deakin University, lead author of a
paper in
Nature Communications.
"The mysids, in return, swim over that farm all day and passively pump out waste material. All that extra waste acts as fertiliser, improving the farmed algae, and, in turn, the condition of the farmer, the damselfish."
This is known as a "domesticator-domestica relationship", a mutually beneficial arrangement where one species provides ongoing support to another in exchange for predictable benefits, such as cleaner fish picking parasites off other fish or insects pollinating flowers.
Humans have had such relationships with many different animals since domesticating dogs around 10,000 years ago, selectively breeding them for certain appealing characteristics such as tameness.
Other examples of non-human domestication are best known in insects that tame plants such as
fungi-farming ants. This study shows non-human vertebrates also domesticate other animals and suggests it may be more commonly than previously known, says Booker.
Comment: Another woman was killed by an elephant in the state of Odisha on the same day.