Dania Albini, who looked under a microscope in 2016, looked at algae-eating daphnia. Its intestines were filled with ingested small Chlorella vulgaris algae and looked green. But she also observed bright green specks of this phytoplankton in unexpected places: herd pouch of herbivores.
“I was really amazed to see them there,” Dr. Dr. Swansea, then an aquatic ecologist at the University of Swansea in Wales. Albini said.
As colonization continues, birds wrap around the eggs of small organisms and kill some of them, resulting in fewer newborns. Research It was led by Dr. Al Beanie and presented at the Royal Society Open Science on Wednesday. With the algae still alive, researchers suspect that chlorella deploys an offensive strategy as opposed to normal defense to protect itself from herbivores.
“I don’t expect food to attack predators in this way,” said Dr. Albini. “We expect from parasites, but not food. It’s fascinating.”
Phytoplankton are usually single-celled photosynthetic organisms that form the basis of the underwater food chain. Among them, microalgae, such as Chlorella vulgaris, float on the surface of ponds and lakes, and can easily eat prevalent zooplankton, such as daphnia trees. To prevent pastures, some microalgae form thorns, release toxins, or aggregate to a size larger than a predator can swallow.
However, sometimes chlorella enters the body of pastures, rather than being fed by the belly, but into rooms with offspring of zooplankton. Water circulates through this breeding chamber, providing oxygen and nutrients to the pups and appears to attract some algal cells. While in this room, researchers discovered that algae can be alive and double in abundance during laboratory experiments that mimic some natural conditions.
When birds were able to colonize their breeding chambers, zooplankton produced very few viable eggs. Kam Tang, Swansea’s plankton ecologist and co-author of the study, says the “biological adhesives” produced by chlorella cells helped stick together, perhaps helping suffocate most of the zooplankton. Next generation.
The unexpected occurrence of chlorella cells inside the reproductive chambers of herbivores was a surprise to Thomas Kiørboe, a marine ecologist at the Danish Institute of Technology who was not involved in this study. “But before, no one would have actually found it,” he said.
Why is chlorella involved in this harmful invasion? Researchers suggest that this attack strategy could prevent algal cells from grazing and in the long term could lead to a decline in zooplankton populations in the lake.
But what is still unknown is whether the live chlorella inside the daphnia cub’s room actually drains into the water or remains trapped.
“There is no reason to assume that this is beneficial for algae,” said Dieter Ebert, an evolutionary biologist at the University of Basel, Switzerland, who was not involved in the study. “They have no chance to get out.”
Dr. Kiørboe is skeptical of this chlorella survival strategy. “Their interpretation can be difficult,” he said, unless it is known that the individual chlorella cells inside the hatchery benefit themselves.
The researchers plan to do long-term experiments to see if algae cells escape when daphnia dies, for example.
“It’s tricky to study unusual phenomena,” Tang said. “It’s especially contrary to what many people think.”