Researchers found that disco clam has a flashy defence mechanism a spectacular light show to scare away potential threats.
This small 3 inched long clam has tiny silica spheres which shines can reflect. The clam has a unique ability to use this strategy both for attack and defence mechanism. It uses this flash ability to intimidate the predators and attract the light-loving prey said Study’s lead researcher Lindsey Dougherty, a doctoral candidate of marine biology at the University of California, Berkeley.
“When most people imagine clams, they imagine the things that make clam chowder,” Dougherty said. “These clams are very different. They’re reef-dwelling, they have bright-red tentacles, they have gills that stick out, they live in little crevasses [and] they are the only species of clam that flashes.”
The researcher tested this unique ability by putting disco clam in an aquarium and used Styrofoam lid to mimic a looming predator, actually “which turned [out] to be very scary” for the clams, Dougherty told Live Science.
The flashing rate of the clam almost turned twice when the lid was nearby. It actually altered its flashing from 1.5 to 2.5 flashes per second. The researchers have found another defence mechanism of this organism that is the use of sulphuric acid against its prey.
Dougherty used calcium chloride, which produces white precipitate in the presence of sulphuric acid. “I found about twice as much precipitate in the disturbed clam than in the calm clam that I just left alone,” she said.
The use of sulphuric acid is common in other marine creatures like snails some and other clams. The sulphuric acid could be a critical part of the clams’ defence strategy. “If you’re flashing and saying, ‘I’m distasteful; don’t eat me,’ that’s one thing, but you have to sort of back it up,” with something like sulphuric acid, Dougherty said.
This strategy worked as a wonder against a peacock mantis shrimp. At first, the mantis struggled to open the clam and then suddenly recoiled and left the clam alone. It usually takes a mantis shrimp about 45 minutes to crack open a clamshell, so “that is very strange behaviour [for the mantis shrimp],” Dougherty said. “They’re very aggressive critters, and to have a clam open and flashing, and the mantis shrimp not attacking, is very weird.”
According to Dougherty its likely for the clam to use sulphuric acid or any other irritating agent to protect itself.
According to the researchers the clam can flash more times in a second in real environment against its predator like plankton. So in order to look deep into it the team has future plans to travel to Indonesia this year to have a closer look on this creature.
Another test found that, although the clams have about 40 tiny eyes, their vision likely isn’t good enough to detect the flashing of other disco clams for mating purposes. Researchers think disco clams are born as males and then change into females as they age, but it’s unlikely that the clams use their flashing light show to attract mates, she said.
Jeanne Serb, an associate professor of evolutionary biology at Iowa State University who was not involved with the study said that Dougherty’s team may be the only group currently researching the disco clam.
“Nobody knew why they did it or how they did this, and that’s why Lindsey [Dougherty]’s work is so important,” Serb said.
“What Lindsey’s work is going to help with is, getting some focus on this large group of organisms that actually have lots of really strange and unusual functions and interesting traits,” Serb said. “And I think this gets back to what is going on with their DNA.”
This unpublished research was presented Jan. 4 at the 2015 annual conference of the Society for Integrative and Comparative Biology in West Palm Beach, Florida.