Baby starfish may seem innocent and adorable, but they are teenage cannibals and eat their own siblings for their own survival, according to a new study.
Two researchers discovered this behavior among baby Forbes’ starfish (Asterias forbesi) by accident. They originally tried to understand how baby sea stars react when they are introduced to vicious predators in the laboratory.
“But everyone started eating each other before we even suggested the crabs. So we had to eliminate the experiment,” said Jon Allen, associate professor in William & Mary’s Department of Biology. said in a statement. Therefore, Allen and his team shift gears to observe this previously unknown phenomenon under the baby starfish.
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The Forbes’ starfish, which are usually found on the east coast of the United States, can grow between 4.7 and 9.4 inches (11.9 and 24 centimeters) in length as adults. according to National Geographic. Juvenile stars in the sea are basically versions of their pin-sized parents, Allen said. These starfish undergo a process called metamorphosis, in which they change from an immature form to an adult form, just as caterpillars change into butterflies.
These starfish, in their immature larval form, look like ‘strange little spaceships’ flying through the water, says Karina Brocco French, a doctoral student at the University of California, Irvine (who was an undergraduate student during this research in Allen). lab worked). ). They stay in this strange little spaceship stage for about a month before changing with young stars and settling on the seabed, Brocco French said in the statement.
Scientists already knew that juveniles on the seabed would eat the much smaller larval forms that would sink to the bottom, but they did not realize that juveniles would eat each other. Although the juveniles were about the same size as each other, the slightly larger ones always ate the smaller ones, according to the statement.
French and Allen discovered that the baby sea stars had been participating in this cannibalistic behavior for four days after metamorphosis. They did this using one of their multiple stomachs, known as their ‘heart stomach’, which pushes them out to swallow and break down their food.
Sibling cannibalism can give the individual stars an adaptable advantage, especially since adult female starfish produce 5 million to 10 million eggs annually, Allen said.
Although such behavior was unknown in this species, cannibalism is not uncommon in the animal kingdom, with more than 1,300 species (including humans) being demonstrated, according to the statement. And the researchers think cannibalism is likely to spread even more widely among small animals, including juveniles.
The findings were published in the journal on March 26. Ecology.
Originally published on Live Science.