From the perspective of scientists, a giant clam is an intimidating creature.
But what if it could mimic a predator, one with a more intimidating name: a snail?
That’s the premise of a new study that shows how a snails’ tail could actually be a way to “stun” a predator.
Scientists from the University of Edinburgh and the University College London (UCL) examined the tail of the world’s largest sea snail, the Cretaceous-era horned sea snail Cnidaria, as part of a long-term research project that seeks to understand how sea creatures function in the wild.
The snail was collected in the Gulf of St Lawrence off the coast of Newfoundland in 1988.
At the time, the horned snails were widespread throughout the seas.
It was the largest horned marine animal known, with a total length of about 3.5 metres (12 feet).
The study, published in the Proceedings of the Royal Society B, suggests that the horn was once part of the shell of the sea snail.
But after the shell cracked, the shells of the horn-bearing snails fused together, resulting in the horn protruding through the shell.
This resulted in a larger and stronger shell, making the horn even more intimidating to predators, said lead author Prof David Leckie.
The team measured the shell length using electron microscopy, and compared it to the width of the tail, which was measured from the top of the snails head.
They found that the tail was just 1.3 millimetres (0.4 inches) longer than the length of the entire horn, which means that it was more like a sword than a spear.
“When the shell is cracked, it has an impact on the surrounding area, which could affect prey that’s swimming towards the snail,” Leckies team leader Dr Michael Cottrell said.
“This means that when the shell cracks, there is an opportunity for the predator to grab hold of the prey and fling it away.”
Researchers then used a method called bioelectricity to mimic the effect of a snipper tail on prey.
They injected an electric current into the horn, then measured how much electricity was transferred through the horn when the current was applied.
“When the horn is fully cracked, and the shell has been replaced by the shell itself, it can’t transfer any further electric charge through the animal, so the animal is completely helpless,” Leksie said.
The result was that the snail was able to immobilise prey, as well as deter the prey’s predators.
The scientists believe that the increased energy released by the snail’s tail was the result of a complex interaction between two chemical reactions: a chemical called hydroxyapatite, which reacts with water to form hydroxyacetate, which forms the skeleton of the snail; and a protein called pyrroloquinone, which allows the protein to bind to proteins that were previously broken down.
“The shell was able just to immobilize the prey without any effort,” Lecksie said.
“It’s quite remarkable that the snipper’s tail could do this.
When the shell was cracked, this reaction was occurring, and it is a key part of this interaction.”
The scientists also tested the effectiveness of their new technology on the horn of a smaller horned species, known as the sea cobra.
They used a similar technique to mimic how the horn in a sea cobrat would immobilise its prey, but found that their horn had a much higher potential to immobilisation.
“It’s a very high potential to break down a target, so it is important that this horn is effective,” Lecches team leader Professor Nick Kipke said.
“We can’t predict what the future will bring, but we’re hoping that this research will help us to design a better deterrent, and help us make smarter decisions about what to do with endangered species in the future.”
This article was originally published by National Geographic.