Marine Snails Have Unique Swimming Patterns, New Study

A snail in a rain shower. Photograph: Henning Kaiser/AFP/Getty Images
A snail in a rain shower. Photograph: Henning Kaiser/AFP/Getty Images
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Marine Snails Have Unique Swimming Patterns, New Study

A snail in a rain shower. Photograph: Henning Kaiser/AFP/Getty Images
A snail in a rain shower. Photograph: Henning Kaiser/AFP/Getty Images

In the world's oceans, billions of tiny marine snails commute daily between surface waters, where they feed at night, to depths of several hundred meters during the day to rest.

Marine snails play an important role in geochemical cycles and climate: 12-13% of the global carbonate flux occurs when the calcium carbonate shells of dead snails sink to the depths, where they dissolve and contribute to atmospheric carbon and ocean acidification. But because they are difficult to study and can't be kept in the laboratory, the behavior of these animals is poorly known, especially for the subtropical and tropical regions where their diversity is greatest.

According to a study published Monday in the Frontiers in Marine Science journal, a US team led by researchers at the University of South Florida tried to address this lack of information. They filmed the movements of tropical marine snails and analyzed these both from a fluid physics and ecological perspective. They showed that each species has a distinct style of swimming and sinking depending on the shape of their shell (coiled, elongated, or round), and body size.

Between 2017 and 2019, the researchers caught multiple individuals of nine species of marine snails and transported them to the laboratory, where they recorded their behavior in a salt-water aquarium with a high-speed technique that tracks movement in 3-D with a pair of cameras. For each species, they calculated the absolute and normalized speed (relative to body length) during active swimming and passive sinking, the frequency of wing movement, the angle of descent during sinking, the tortuosity of the path of ascent during swimming, and the shells number.

The researchers found that each species has a distinct swimming pattern. Tiny snails with coiled shells swim more slowly whereas larger snails with bottle-shaped or wing-shaped shells swim faster because their larger sizes allow them to overcome the effects of water viscosity.

In a report published by the Frontiers in Marine Science journal, author Dr. David Murphy, assistant professor at the Department of Mechanical Engineering of the University of South Florida, said: "Understanding the swimming ability of these animals is helping us better understand their ecological importance and distribution in the ocean. Further, we hope to learn from the swimming style of these organisms to design a new generation of bio-inspired underwater vehicles."



A Stroke Survivor Speaks Again with the Help of an Experimental Brain-Computer Implant

The scientists used a synthesizer they built using her voice before her injury to create a speech sound that she would have spoken. (Getty Images)
The scientists used a synthesizer they built using her voice before her injury to create a speech sound that she would have spoken. (Getty Images)
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A Stroke Survivor Speaks Again with the Help of an Experimental Brain-Computer Implant

The scientists used a synthesizer they built using her voice before her injury to create a speech sound that she would have spoken. (Getty Images)
The scientists used a synthesizer they built using her voice before her injury to create a speech sound that she would have spoken. (Getty Images)

Scientists have developed a device that can translate thoughts about speech into spoken words in real time.

Although it’s still experimental, they hope the brain-computer interface could someday help give voice to those unable to speak.

A new study described testing the device on a 47-year-old woman with quadriplegia who couldn’t speak for 18 years after a stroke. Doctors implanted it in her brain during surgery as part of a clinical trial.

It "converts her intent to speak into fluent sentences," said Gopala Anumanchipalli, a co-author of the study published Monday in the journal Nature Neuroscience.

Other brain-computer interfaces, or BCIs, for speech typically have a slight delay between thoughts of sentences and computerized verbalization. Such delays can disrupt the natural flow of conversation, potentially leading to miscommunication and frustration, researchers said.

This is "a pretty big advance in our field," said Jonathan Brumberg of the Speech and Applied Neuroscience Lab at the University of Kansas, who was not part of the study.

A team in California recorded the woman’s brain activity using electrodes while she spoke sentences silently in her brain. The scientists used a synthesizer they built using her voice before her injury to create a speech sound that she would have spoken. They trained an AI model that translates neural activity into units of sound.

It works similarly to existing systems used to transcribe meetings or phone calls in real time, said Anumanchipalli, of the University of California, Berkeley.

The implant itself sits on the speech center of the brain so that it’s listening in, and those signals are translated to pieces of speech that make up sentences. It’s a "streaming approach," Anumanchipalli said, with each 80-millisecond chunk of speech – about half a syllable – sent into a recorder.

"It’s not waiting for a sentence to finish," Anumanchipalli said. "It’s processing it on the fly."

Decoding speech that quickly has the potential to keep up with the fast pace of natural speech, said Brumberg. The use of voice samples, he added, "would be a significant advance in the naturalness of speech."

Though the work was partially funded by the National Institutes of Health, Anumanchipalli said it wasn't affected by recent NIH research cuts. More research is needed before the technology is ready for wide use, but with "sustained investments," it could be available to patients within a decade, he said.