11/10/2011 07:17 BST | Updated 11/12/2011 05:12 GMT

Megavirus Chilensis: Ocean Trawl Discovers World's Largest Virus

The world's largest virus has been discovered off the coast of Chile.

The virus, known as Megavirus chilensis, is 10 to 20 times as wide as normal viruses and is bigger than some bacteria.

It was discovered near to Las Cruces in central Chile in a general trawl of the area for interesting biology.

Scientists have told the journal PNAS that the virus infects single-celled organisms floating in the sea, and does not pose a danger to humans.

The Megavirus' unusual size beats the previous record holder, Mimivirus, which was discovered living in a water cooling tower in the UK in 1992.

However those with over-active imaginations should relax, as the virus is still relatively tiny at 0.7 micrometres in diameter.

"You don't need an electron microscope to see it," Professor Jean-Michel Claverie, from Aix-Marseille University, Marseille, France, told the BBC. "You can see it with an ordinary light microscope."

Studies of the Megavirus show that it has more than 1,000 genes, and uses hair-like structures on its shell to attract amoebas to infect and use to replicate itself.

"Everything is initiated from a single particle, and then grows and grows to become this virion factory," Prof Claverie said. "That's why it needs all these genes."