There are animals and there are plants. And sometimes, there are both at the same time. As long they’re mutually beneficial, these relationships are called symbioses. Otherwise, we’re talking about parasites. According to a study led by a researcher from the UK, mint-sauce worms are symbiotic social sun bathers.
The mint-sauce critters
University of Bristol’s Nigel Franks has always been interested in the social behavior of insects. Generally interested in ants, he found out from a book about these symbiotic creatures at some point, and he decided to go on a quest. After a few seasons, he finally found some of the critters on a beach.
Mint-green because of the algae growing inside and on them, the worms are in a symbiotic relationship. The algae get a place to live, and the worms never have to eat thanks to the algae’s photosynthesis skills. It’s a win-win situation.
After they found a bunch of the creatures on the beach, Franks and his group of students observed something very strange about them – the two millimeter long worms were engaging in something called a milling behavior. This means that they were moving in circles with one another, nose to tail.
This behavior is often found in some fish, ants, and some caterpillars, all of them being social creatures. Nobody having observed the mint-green worms engage in social behaviors before, Franks decided to figure out exactly what was going on with these fascinating symbiotes.
By filming the critters’ behaviors and replicating them via multiple computer models and simulations, the team discovered that computer worms didn’t engage in the same behaviors as the real ones. This was because there was data missing which didn’t have anything to do with instincts.
Further looking into this, the team created a second simulation in which the worms were instructed to interact with each other. The results were far more similar to the real life mint-green worms. After further observing the real life creatures and how they behave when in strong sun, Franks finally came up with the answer.
When in powerful sun, the worms tended to start their milling movements as close to each other as possible, eventually forming a dog-pile of sorts, only one that kept moving. Then, in order not to be affected by the exceedingly powerful sun, they form a sort of biofilm.
No, they don’t coat themselves in a biofilm, instead they act like one. By forming a sheet in a very dense layer, each individual worm had its turn at getting sunlight and getting back under cover before they got over-exposed. This type of coordination speaks of the critters as being highly social, probably at the same level as ants or bees.
Image source: Flickr