When we imagine a choir, it is likely that it will not walk around. In fact, in most cases, corals are sessile, which means they are fixed to the surface of their habitatoften the Recife built from the bones of its ancestors.
Among them, a tiny coral-curlcalled Cycloseris cyclolitesHe found a way to propel himself through sandy marine backgrounds to literally chase the sun.
According to, a team led by Brett Lewisfrom the University of Queensland, used videos in timelapse to Observe the corals to move through their tanksusing a Strategy similar to the meduses – The cousins without the ties of the corals.
On a scale of human time, this is a painfully slow shape to move. A choir moved only 43.73 millimeters over 24 hours.
In the first hour, more or less, Lewis observed the coral swelling as its ost external tissues inflamedwhich allowed the center of the choir to be lifted from the seabed.
“I watched this thing for a long time, thinking that I was going to burst,” said Lewis. “I thought, my God, this is taking a long time to happen.”
Then, when the inflated tissue contracted, the contact with the surface was transferred to a kind of “foot” structure under the coral, which allowed it to advance.
Estes movements were coordinated towards a certain source of light through the contraction and twisting of the outer tissue“,” Which propelled the choir forward in a coordinated way, similar to the pulsating swimming movement of the medusas, “the researchers wrote in a new study at PLOS One.
This must be a exhaustive task for a coral colonyBut it is worth it when it is considered that gravity, waves, chains and even other creatures can easily move these corals to less than ideal places.
Most corals depends on a symbiosis with dinoflagellates incorporated into their tissues. These unicellular organisms produce energy from sunlight, which is then collected by the choir.
The location – and the light that comes to it – crucial.
For a free life choir like the Cycloseris cyclolites get out of a dark ditch, for a long time it takes, It may be the difference between life and death.
“Our findings suggest that pulsed inflation is not just a survival strategy, but a critical mechanism for migration and navigation“Says Lewis.
“The ability of Cycloseris cyclolites to move toward specific light sources is a fascinating parallel with other marine specieslike the jellyfish, which suggests that they are more sophisticated from the neurological point of view than thought. ”
To see the corals in action, their tanks were wrapped in almost darkness, with a white or blue bait at one end.
The corals look motivated mainly by blue light, with 86.7% of the corals to look for itcomparatively with only 13.3% when white light was offered.
When it was offered blue and white light, one at each end of the aquarium, the Three corals involved in the experience chose Azul.
The narrow sources of light (~ 420 nm and ~ 510 nm) are similar to habitat From coral species, the deeper water beds, where light waves over approximately 480 nm cannot reach.
White light, with its wavelength amplitude, is more similar to low surface waters.
Temperatures of Small waters can be harmful For the exploration of dinoflagellates of the corals, as is true of the coral bleaching, which may explain why corals prevent water with white light.
“The discoveries also have important ecological implications“Says Lewis.
“Understanding their movement strategies can help scientists predict how migratory corals can resist, survive or adapt to changes in environmental conditions, such as sea surface changes caused by climate change, which can be reduced in the deepest waters where these corals migrate.
“With the increase of these climatic factors, The faster the migration, the greater the hypotheses of survival“.
Teresa Oliveira Campos, Zap //
