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Ever since the 'disco clam' was caught on camera 'partying' on the ocean floor, its behaviour has fascinated, and baffled, scientists. 

Last year, an expert revealed that the clam's lips are packed with 'mirror ball' style reflectors that help it produce its strobe light effect.

And now the same scientist has discovered this impressive light show is designed to lure prey towards the mollusc, before the clam paralyses its victim with toxic mucus.

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Research from the University of California, Berkeley suggests that scaring off predators or luring prey may explain the disco clam's flashy behaviour (pictured). The disco clam is an active, filter-feeding mollusc that lives in crevices and small caves in Indo-Pacific coral reefs

Ctenoides ales, dubbed disco clam because of its unique feature, produces the effect using its lips - which is packed with tiny spheres of reflective silica - like a mirror ball.

Lindsey Dougherty from the University of California, Berkeley encountered the two-inch clam in 2010 while diving with her mother and sister in Wakatobi, Indonesia.

She saw Ctenoides ales roll the edge of its mantle - a layer of muscle and tissue that acts like a cloak over the mollusc's body - and produce a strobe-light effect using its mirrored lips.

The disco clam is an active, filter-feeding mollusc that lives in crevices and small caves in Indo-Pacific coral reefs. 

Their flashing is so bright, it had been previously thought to be the result of bioluminescence. 

However, using high-powered transmission electron microscopy, Ms Dougherty discovered that the flashes are caused by specialised tissues that form a double layer, reflective to light on one side, but absorbent on the other. 

When the tissue is rapidly rolled and unfurled by the clam, the reflecting light gives the appearance of flashing. 

These tissues are so reflective that they can even flash using the low levels of blue light found in the caves. 

They are the only species of bivalve to have evolved structural colouration of this kind, and this latest project set out to discover why.

Ms Dougherty and her colleagues began by examining the structure and proteins in the clam's eyes using a powerful microscope. 

From this they concluded that its vision is likely to be too poor to allow it to observe displays by other clams, suggesting the flashing is not produced to attract a mate.

Next, they tested the effect of the flashing on predators, which in the wild might be octopi, predatory snails, or mantis shrimp.  

Disco clam has electrically charged lips and tentacles

During further tests, researchers also found high levels of sulphur in the clam's tentacles. A peacock mantis shrimp that was attacking the disco clam seemed to recoil from its tentacles and enter a catatonic state. This suggested to the team that the clams may be producing noxious, acidic mucus to repel predators

Using so-called 'looming' trials, during which the researchers moved a false predator in the direction of the clams, they were able to track the frequency of the flashing. 

'In this case, the false predator was just a styrofoam lid,' said Ms Dougherty. 

'But it turns out a styrofoam lid is indeed pretty scary to the clams, because their flash rate almost doubled from just under 2 Hz to just under 4 Hz.'

During further tests, the researchers also found high levels of sulphur, the key ingredient in sulphuric acid, in the clam's tentacles.

A peacock mantis shrimp that was attacking the disco clam seemed to recoil from its tentacles and enter a catatonic state.

This suggested to Ms Dougherty that the clams may be producing noxious, acidic mucus to repel predators.

Finally, phytoplankton prey were introduced into the clam's tank. 

As the clam's tentacles began to sense the presence of prey, the flash rate increased significantly.  

Phytoplankton prey were introduced into the clam's tank, and as the clam's tentacles began to sense prey, its flash rate increased significantly. Many species of plankton are phototaxic, meaning they are attracted to light

Many species of plankton are phototaxic and therefore attracted to light, though it is unclear whether the disco clam's prey species are able to see their flashing.

Ms Dougherty, said: 'I've dived with humpback whales and great white sharks.

'But when I saw the disco clam, I was enamoured. I said then, "I'm going to do a PhD on the disco clam."'

Ctenoides ales are found in tropical areas, typically in clusters of two or more.

Light is dim and blue-green at the clams' typical depth, which ranges from 10 to 150 feet  (3 metres to 50 metres) but their rippling mirrored lips are visible even without artificial illumination.