- James Weiss recently captured one of the first known records of a tardigrade trio.
- Videographers have also captured pairs of tardigrades mating for up to two hours at a time.
- The trio of water bears lasted about 30 minutes, sticking their bellies and pooping.
The tardigrade is microscopic creatures Comes with survival gift. These aquatic invertebrates – aka water bears or moss piglets – can withstand exposure to high levels of radiation. deep sea,Furthermore the vacuum of space.
We also know that water bears have some pretty wild sex thanks to recent video footage by scientists. James WeissYouTube channel videographer Journey into the Microcosm and” authorBeauty hidden in the microscopic world.”
Mating of male and female tardigrades.
James Weiss
Weiss expert using a microscope To study microbes in ponds, lakes, rivers, and seas, the same petrels were observed for weeks in enclosed environments on slides. That’s how he shot footage of tardigrades mating. 2 hours at a time.
he also 30 minute tardigrade trio — One of the first known recordings of tardigrade group sex.
Image 30 on this slide from 1914 shows the earliest known image of water bear group sex, with five males clustered around a large female.
Wanda von Wenk, 1914
water bear trio
Researchers are the first to publish details of the mating behavior of tardigrades. 2016 paperbut other observations of water bear sex are rather limited.
“Until very recently, not many people studied tardigrades, so all these observations come from a couple of well-known tardigradologists,” said Weiss. Words, he added.)
“We don’t study tardigrades in a traditional, institutional way, but we’ve been interested in them for a long time, so we’ve collected a lot of data and observed their unique behavior,” says Weiss. said.
One of those unique behaviors? A trio of water bears.
While observing tardigrades on a slide, Weiss first noticed two small tardigrades that appeared to be attracted to the underbelly of a larger tardigrade. This was unusual, as tardigrades usually do not show such intense interest in anything.
However, after 20 minutes, the two smaller tardigrades continued to peck at the larger tardigrade. Not an expert on tardigrades, but having seen enough of them in the study of microscopic organisms, Weiss noticed that the larger tardigrades appeared to carry unfertilized eggs.
A female tardigrade is on her left, with two males piercing her underbelly.
James Weiss
He said the two tiny tardigrades were males “shooting shots” to fertilize the female’s eggs.
As Weiss watches, he said, two males continue to poke the female while she poops.
A female tardigrade with unfertilized eggs circled in red.
James Weiss
Weiss added, however, that it was impossible to ascertain exactly why she had a bowel movement due to the limited understanding of the tardigrade’s sexual behavior among experts.
“Underwater, everything is about chemical cues, so males have to gather some information to find females,” Weiss said.
To test this, Weiss separated several mating couples by gently poking them with cat hair through microscope slides and coverslips. In both cases, males reverted to females within minutes.
Two male tardigrades (top) are not distracted by the rising poop cloud.
James Weiss/Journey into the Microcosm
“So I think there’s some kind of chemical signaling going on. When you poop, you release a lot of signals into the water,” Weiss said.
After about 30 minutes in all, the trio became a duo when one man left the scene.
The remaining males stuck with the females for an additional hour, and Weiss observed mating behavior similar to other tardigrade couples on the slide.
breeding water bears
A female tardigrade with oocytes circled in red.
James Weiss
Males are attracted to females with unfertilized eggs or oocytes.
In his book, Weiss observed that males always seemed to give chase. I jumped in and stayed there for an hour and a half,” he wrote.
A male tardigrade rides on the back of a female.
James Weiss
When a male finds a female, it clings to the female with its claws and the partner makes wild rhythmic movements until eventually the male exits and may enter an opening in the female’s exoskeleton to fertilize the egg. Release thousands of sperm.
But scientists still can’t figure out exactly how fertilization occurs.
The tardigrade sperm is circled in red.
James Weiss
Not all tardigrades need to have sex to reproduce.Weiss said Some species of tardigrades contain only females, A person who reproduces asexually by parthenogenesis.
He also said that tardigrades may switch reproductive methods when under environmental stress, but experts still have a lot to learn about this theory.
However, like the species Weiss documented, marine tardigrades include both males and females, and reproduce by mating.
Male tardigrade testes circled in red.
James Weiss
Birth of Mizukuma
A sea bear mother may carry as many as 20 eggs before they start hatching, one popcorn-like egg at a time, Weiss said.
pregnant water bear.
James Weiss
“Newborn tardigrades are easy to spot because they are hungry, and after a week they are ready to breed, so two weeks after hatching, the babies are born,” says Weiss. .
Eggs of tardigrades hatch.
James Weiss
Water bears have fairly short lifespans, with the longest lifespan Weiss observed in his study being eight weeks.
Watch the tardigrade threesome video belowwith a timestamp around 13:25.