Scientists have solved a long - running enigma surroundingmarimo , the fuzzy chunk of green algae that Japan considers anational treasure .
Though marimo are known for cuddle adorably at the bottom of rivers and lakes , they ’re not always bottom dwellers . They pass at night , but during they day , they float — and until now , researcher were n’t quite sure why . AsAtlas Obscurareports , a novel study gets to the bottom of the mystery : It ’s photosynthesis .
The study , published inCurrent Biology , find that floating and sinking are instinctive byproducts of the marimo ’s circadian rhythm labour by photosynthesis .
During the day , ripple form within the spherical balls ofAegagropila linnaeialgae , making them be adrift to the surface of the water . In monastic order to happen out what drives the formation of these bubble , researchers from the University of Bristol used a chemical substance that block photosynthesis . They found that bubbles did n’t take form on chemically altered marimo , nor did the alga balls float , even when they were expose to 48 hours of unceasing light .
Once they knew that photosynthesis was primal to marimo buoyancy , the researchers exposed their science laboratory - grown marimo to unlike clean shape so as to try whether their circadian rhythm plays a role in floating . The marimo were expose to 12 hour of dark and 12 hours of light source during the 24-hour interval , then transferred to an environment with constant dim , red lighting for a few days . When the researchers then expose these alga balls to bright light at the get-go of the day — mimicking the natural light cycle — they find out that the marimo floated to the top of the water quicker than they did if they were exposed to smart lighting in the heart of the day . Basically , the marimo had jet plane lag .
The researchers indicate that this day - night buoyancy oscillation might help the marimo maximise the amount of light they get each day . Since there ’s less Inner Light at dispirited depths ( like at the bottom of a lake ) , marimo be adrift to the top of the body of water to maximise their potential for photosynthesis each day .
Marimo are endangered in the wilderness , and are no longer observe in many of the lake that were once swarm with the balls of algae . Given that photosynthesis drive the marimo ’s daily cycle , these population alteration could be due to pollution changing how much light come home the water in those lakes , according to Dora Cano - Ramirez , the subject field ’s first author .
[ h / tAtlas Obscura ]
