Nemo, the charming clown in the movie Finding Nemo, rubs himself all over the anemone in which he lives, to prevent him from stinging and eating him, like most fish. According to a new study, this friction leads to a change in the composition of microbes covering the clown fish.
The presence of bacterial coaches, common with anemones, can help the clown to nest in the poisonous tentacles of anemones, a strange symbiosis that scientists and scientists, including the team from the Georgia Institute of Technology, have been trying to figure out for decades. Marine researchers studied microbes on clowns, which were mixed and mixed with anemias that kill fish.
“This is a landmark mutual approach between the host and the partner, and we knew that microbes are on every surface of each animal,” said Frank Stewart, associate professor at the School of Biological Sciences of Georgia. "In this particular reciprocity, these surfaces are covered with what germs love to eat: mucus."
Clownfish and anemones replace a lot of mucus when they rub. So, the researchers brought clown fish and anemones together and analyzed the microbes in the mucus that covered the fish, when they were arranged by anemones, and when they were not.
“Their microbiome has changed,” said Zoe Pratte, a doctoral research student at Stewart's laboratory and the first author of a new study. "The two bacteria that we tracked, in particular, multiplied by contact with anemones."
“In addition, there have been radical changes,” said Stewart, the principal investigator of the study. "If you looked at the full aggregate of microbes, they looked quite differently on the clown, which was arranged by an anemone, but on what was not."
Researchers chased 12 clowns in six fishing tanks for eight weeks to lubricate their mucus and identify microbes through gene sequencing. They published their results in a journal Coral reefsThe study was funded by the Simons Foundation.
Questions and answers
Here are a few questions and answers about the experiment, in which some funny jokes were made, as well as fascinating facts about anemones and a clown. For example: red urine on anemones makes the latter stronger. Clownfish changes floors. And it is especially difficult to catch one fish, which the researchers called “Houdini”.
Does this solve the mystery about this strange symbiosis?
No, but this is a new approach to the clown-anemone puzzle.
“This is the first step that asks the question:“ Is the constituent part of microbial relations changing? "- said Stewart. The study provided a response on the side of the clown, which was "yes."
An earlier hypothesis about the puzzle was that the plum mucus was too thick to swallow it. Modern ideas suggest that mucus replacement also covers clone fish with anemonic antigens, that is, its own immune proteins, or that fish and killer fish can exchange chemical messages.
“An anemone can recognize some kind of chemical in a clown fish that prevents it from stinging,” said Stewart. “And this may be due to microbes. Microbes are great chemists. ”
Moving forward, researchers want to analyze the chemistry of mucus. They also do not yet know to what extent the microbes on the fish change due to the bacteria that the fish extract from the anemone. Perhaps the microbiome of the fish mucosa only develops differently in fish due to contact.
What do anemones usually do to fish?
Kill them and eat.
“Anemone evolved to kill fish. He shoots small poisonous darts at the fish's skin to kill her, and then drag her into his mouth, ”said Stewart. "The clown fish leaves life right in this."
By the way, the tentacles are not harmful to humans.
“If you touch an anemone, it seems that they sucked with a finger,” said Pratte. “Their little harpoons feel like they are sticking to you. It does not hurt".
What do anemones and clown fish make from a relationship?
To begin with, they protect each other from potential prey. But there are many more. Some clowns even change their sex while living in an anemone.
“When they start to take it, the fish takes a big step forward,” said Stewart. "The first fish in a group that sets itself up in the anemone in the wild transitions from men to women grows much larger and becomes the dominant member of the group."
Then she is the only woman in the school of small men-men.
Anemones seem to grow larger and healthier, in part because clown fish drench them.
“When the fish urinates, the algae in the anemone take up nitrogen, and then they release the sugars that feed the anemone and make it grow,” said Pratte. "Sometimes the fish throws food, and it gets into the anemone that eats it."
Any funny jokes from this experiment?
Much: it was scientifically simple, but painstakingly carried out, in part because the researchers followed the fish closely at the same time.
“You have to collect fish and anemones, and the fish can take in other places, such as bells in stone,” said Pratte.
“Clownfish is smarter than other fish, so it's harder to catch them, especially when we want to minimize animal stress,” said Alicia Kogman, research assistant at the Quick Switch to Research program at the Biological Science School. "We called one fish" Houdini. " He could move between networks and narrow spaces and usually outwitted those who tried to catch him. ”
“We also had“ bubbles ”that blew up a lot of bubbles,“ Biggie ”and“ Smalls ”,“ Broad ”,“ Sheila ”,“ Earl ”and“ Flounder ”who loved to prick (flop around),” Pratte said . Clownfish have different sizes and details in their own bands, which allows people to tell them apart.
The anemonic side of the microbial question may be more difficult to answer, because for all the tricks of Houdini, anemones that are soft, not vertebrates, try harder. They can squeeze into uncomfortable niches or connect the aquarium drainage, as well as have temperature microbiomes.