Using tiny computers mounted on the backs of snail shells in Tahiti, scientists have discovered how one species survived extinction while others fell prey to an invasive carnivorous snail, according to a new study .
The rosy wolf snail was introduced to the island in the 1970s as a means of controlling another invasive species, the giant African land snail. But the rosy wolf continued to prey on native tree snails and wiped out more than 50 species.
“They used their sharp teeth on their tongue, and they kind of gnawed at the soft tissue – so raspy. The other way is he would just swallow a snail whole, shell and all,” the ecologist and evolutionary biologist Cindy Bick said As it happens guest host Duncan McCue.
But the white shell Partula hyalina the snail has survived, although the population remains precarious. Bick found that several factors, including their high reproductive rate, helped improve their survival rate, but that still didn’t explain why other snails with similar reproductive rates died.
Researchers have hypothesized that the colors of snail shells contribute to the amount of light they can tolerate, which would give white-shelled snails a biological advantage against darker-shelled predators and, therefore, lower light tolerance.
Snails that can tolerate light might be out during the hours of sunlight, while predatory wolf snails would likely avoid the sun.
In order to test the theory, Bick turned to technology to help track the solar intake of pink snails compared to Partula hyalina.
Bick and other University of Michigan researchers attached tiny computers, measuring 2 x 2 x 4 millimeters, to pink snail shells. They also put computers on sheets housing hyaline particle, rather than directly on the snails, because it is a protected species.
“We’re talking about a snail that’s about the size of your fingertip. So you want to make a computer that’s as small as you can attach it to the snail’s shell. So that’s the first thing. Second thing, what you would probably want to do is make sure it sticks.” says Bick.
Using biodegradable glue, the researchers secured the devices and began monitoring solar data.
The team found that the Partula hyalina are able to absorb higher levels of solar radiation than the rosy snail. They published the study last month in Communications Biology.
“Think of it as hiding in plain sight, hiding in the sun. And think of the Euglandina rosea (pink wolf snails) as a vampire. He can’t really go out during the day, or he’s very limited during the day. But at night, all bets are off,” she said.
For Bick, it was a story of resilience.
“It’s a story that tells us something about what it takes to survive, especially with climate change, habitat degradation…or the introduction of invasive species,” she said. .
“If we are proactive in conserving or taking steps to preserve some of these environments that some of these species can survive in, they are able to hang on a little longer.”
Written by Mehek Mazhar. Interview with Cindy Bick directed by Niza Lyapa Nondo.