small gas stick bandage In Australia, there is no chance against the most dangerous predator: cannibal tadpoles that overeat their young as if they were in an open buffet. But the little ones are now fighting back.
A new study finds that they evolve faster, giving hungry tadpoles less time to devour.
“If cannibals are looking for you, the less time you spend laying eggs or hatching, the better,” said lead researcher Gina Devore, who conducted the study as a postdoctoral research associate at the University of Sydney and is now a biologist. From the Tetiaroa Association, a non-profit environmental conservation organization in French Polynesia.
However, rapid development has its drawbacks. The researchers found that compared to typically growing chicks, those who grew faster did worse when they reached the tadpole’s life stage. So it’s not worth defending yourself in this way unless the cannibals definitely come to you.
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reed frog (Rinella Marina) is a baby poster by Invasive species. The wart-like poisonous frog, known to swallow anything that fits in its wide mouth, is native to South America. In the 1930s, farmers in Queensland, Australia, believed the frog would be the perfect predator to devour beetles that had decimated sugarcane fields. But with no natural enemies below, the number of frogs increased from 102 individuals to more than 200 million. According to WWF Australia.
Another reason for their high numbers is that female frogs can lay more than 10,000 eggs at a time in small ponds. “When these eggs first hatch, the fry can’t swim or eat yet, so they can lie at the bottom of the pond until they develop into tadpoles,” Devore said.
Hungry tadpoles strike during this poor breeding season. “Once the fry develop into small tadpoles, they are too large and mobile for other frogs to eat, so the cannibals have to work quickly if they want to eat them all,” Devore said.
The little frogs that eat the younger generation do themselves a great favor. They obtain nutrients and eliminate the subsequent competition for resources. “When I first saw this behavior in the wild, I was amazed at the voracious way in which he hunted reed mushrooms and ate their young,” Devore said. To determine whether this behavior is “natural” or whether it is an adaptation to intense competition among invasive cane frogs, DeVore and colleagues compared invasive cane frogs in Australia with those in the native range, or cane frogs from their native habitat.
Warty frog arms race
Numerous experiments have shown that invasive frogs – both baby chicks and tadpoles – are cannibals. Develop Very fast.
In an experiment conducted more than 500 times with different individuals, Devore and her colleagues placed one tadpole in a container of 10 fry. While tadpoles from the original range showed some cannibalism, “We found that they were 2.6 times more likely to molt if this tadpole came from Australia than if it came from the original range,” she said.
In addition, the tadpoles were more attracted to the chicks than the original tadpoles. In another experiment, the team placed tadpoles in a pond with two traps. One of the traps was carrying a boy and the other was empty. “In Australia, cannibal tadpoles are attracted to young chicks; the odds of an Australian tadpole getting into a trap with young chicks were about 30 times the odds of a tadpole getting into an empty trap,” Devore said.
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In contrast, “the tadpoles were not attracted to the larvae, they were as likely to be in the empty trap as the larvae,” she said. “This showed that this strong attraction to the weak breeding stage, which helps cannibal tadpoles detect and locate their victims in Australia, is not present in the original range.”
To fight back, the invasive little ones developed an escape strategy. When the researchers compared the time the eggs and fry spent developing, they found that the invasive frogs evolved faster than those in the original range.
In both groups, we found that the claws of cane frogs from Australia developed faster. They reached the tadpole in about four days, while the tentacles of the original range lasted about five days.”
In addition, the invasive chicks had a “plastic” or more agile response than that of normal young chicks when the cannibal tadpole was present; Devore noted that young birds from Australia “could smell better when cannibals are around and their growth accelerates in response.”
While these strategies helped the youngsters survive, they paid for it later. The researchers tested 1,190 tadpoles for survival, growth, growth and resilience, and found that those that evolved faster as eggs and young to escape cannibals fared worse and developed slower in the tadpole stage than did the tadpoles of the original range.
Could cannibalism lead to extinction?
Can cane frogs eat themselves until they become extinct? Probably not, Devore said.
“Australian frogs may be their own worst enemy, but I don’t expect them to be extinct any time soon,” she said. That’s because cannibals benefit a lot from eating their own species. After gaining nutrients and reducing competition, the cannibal tadpoles “turn faster and larger into frogs,” she added. It is even possible that these “successful” frogs invade new places in Australia more quickly.
“The good news is that cannibalism can control population growth,” Devore said. “So, while cane frogs are unlikely to drive themselves to extinction, these cannibal behaviors could help regulate their abundance after invasion.”
The study was published in the August 31 issue of the journal Proceedings of Van de National Academy of Sciences.
Originally published on Live Science.
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