A new study shows that glowing corals living at depths of at least 147 feet display fluorescent colors to attract prey.
- Colorful corals use their glow to attract prey into the deep ocean
- The researchers conducted underwater and laboratory experiments to confirm their hypothesis about why corals glow.
- The study used small brine shrimp, known as Artemia salina, which corals love to eat.
- The findings may be applicable to other fluorescent marine organisms and may play a more important role in marine ecosystems than previously thought, the researchers said.
Corals can grow deep in the ocean and light up dark waters, but now researchers have found that their fluorescent colors serve as a way to lure prey.
Researchers have proven for the first time that the beautiful underwater coral fluorescence in deep reefs, which has fascinated scientists and ocean lovers alike, is meant to attract their food.
“We conducted an experiment in the deep sea to explore the possible attraction of diverse and natural plankton collections to fluorescence under the natural currents and lighting conditions that exist at depth,” said the doctor. Or Ben-Zvi, professor at the School of Zoology in Tel Aviv The university that led the study said Israel Times.
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Researchers have proven for the first time that this beautiful display of underwater fluorescence that corals exhibit in deep reefs is meant to attract their dinner.
To determine if the fluorescence was meant to attract prey, the scientists had to find out if the fluorescence attracted plankton, tiny marine organisms that drift with the current.
This aspect has been tested at sea and in the laboratory.
In each of the laboratory experiments, crustaceans showed a desire for a fluorescent signal.
The researchers then quantified the predatory abilities of the corals studied in their lab.
Pictured above: fluorescent morphs of the mesophotic coral Euphyllia paradivisa.
The researchers used small brine shrimp, Artemia salina, which corals love to eat.
Shrimp given a choice between a green or orange fluorescent target versus a clear one in the lab showed a marked preference for the fluorescent target.
A crustacean from the Red Sea also showed a preference for fluorescence.
The photo shows the experimental setup for the in situ attraction experiment.
“Because fluorescence is ‘activated’ primarily by blue light (light from the deep sea), at these depths the fluorescence is naturally illuminated and the data from the experiment was unambiguous, similar to a lab experiment,” Ben explained Zvi.
In the second part of the study, the researchers conducted an experiment in a typical coral habitat at a depth of about 147 feet – in this case, the fluorescent traps attracted twice as much plankton as the transparent traps.
“Many corals exhibit a fluorescent color pattern that accentuates their mouths or tentacle tips, supporting the idea that fluorescence, like bioluminescence (the production of light from a chemical reaction), acts as a mechanism to attract prey,” Professor Yossi Loya. University, from the School of Zoology and Steinhardt, told Jerusalem Post.
“The study proves that the luminous and colorful appearance of corals can act as a bait to attract swimming plankton to terrestrial predators such as corals, and especially in habitats where corals require other sources of energy in addition to or instead of photosynthesis.” sugar production by symbiotic algae inside coral tissue using light energy).
“Despite gaps in existing knowledge about the visual perception of fluorescent signals by plankton, the current study provides experimental evidence for the role of coral fluorescence in attracting prey,” Ben-Zvi explained in The Jerusalem Post.
“We hypothesize that this hypothesis, which we call the ‘light trap hypothesis’, may also apply to other fluorescent organisms in the sea, and that this phenomenon may play a larger role in marine ecosystems than previously thought.”
The findings of the researchers are published in the journal Communication biology.
In the photo: the results of the experiment to attract plankton are presented as the number of plankton individuals in each trap.