A MONSTER mollusc weighing a whopping 5.5lb has been discovered among Mersea Island's world-famous oysters.

The 2.5kg whopper is 12in long and was discovered by a sub-contractor working for Richard Haward's Oysters on Mersea.

Tom Haward said the oyster had to be the largest his company had ever harvested.

He said: “An oyster that big would be more than 20 years old and would have filtered 1 million litres of water in its lifetime.

“Extra-large oysters are usually best for cooking but tourists who visit our stall in London are always after XL oysters and so when it’s been through our tanks we will see if anyone is interested.”

Tom, who is an eighth-generation oysterman, said the gargantuan oyster was about the same weight as his daughter Autumn, now aged three, when she was born.

Heavy -Heavy - The oyster weighed 2.5kg or 5.5lb (Image: Tom Harward) 

The huge oyster was only 1.5 inches smaller than the largest recorded in by Guinness World Records, and Tom is certain there are more massive molluscs to be found on the oyster bed.

Richard Hayward's Oysters sells about a million oysters a year, including at Borough Market in Southwark in London.

William Haward Snr started cultivating oysters in the 18th Century and now Tom Harward - nicknamed ‘8th Gen’ - oversees an oyster bed the size of seven football pitches on the River Blackwater.

Scale - Autumn Harward, 3, with the oysterScale - Autumn Harward, aged three, with the oyster (Image: Tom Harward)

The company cultivates two types of oysters - the Colchester native and the rock oyster - which are both purified in water from the River Blackwater

The company’s rock oysters are the only wild oysters in the UK.

Wild oysters are very rare as only one in a million survives into adulthood in uncultivated environments.

Richard Haward’s Oysters first cultivate oysters from the rock bed, then move them to oyster beds in creeks that run into the River Blackwater – which they say produces the “best quality” oysters.

Oysters play a vital part in the marine ecosystem, by consuming excess nutrients that fuel harmful algal blooms and by forming oyster reefs which become biodiverse habitats.