World's largest flame shells colony found in Scotland
Around 250 million of the shellfish were discovered at Loch Carron in the Highlands.
The world's largest known colony of a "brilliant but shy" species of shellfish has been discovered at the bottom of a loch.
Around 250 million flame shells were found during survey works at Loch Carron in the Highlands, which is a marine protected area (MPA).
It follows a 2012 discovery in Loch Alsh of a colony of more than 100 million of the molluscs.
Flame shells are small bivalve shellfish with fiery orange tentacles. They spend most of their lives hidden away inside nests.
A huge 185-hectare bed in the MPA has been formed by these nests, which have merged together.
The latest discovery was made by a Scottish Natural Heritage (SNH), Marine Scotland and Heriot-Watt University survey to learn more about creatures living in Loch Carron.
Dr Dan Harries, of Heriot-Watt University's Institute of Life and Earth Sciences, who led the diving fieldwork, said: "This is another fantastic discovery. We really didn't think we'd find a bed that could top the 100 million find in Loch Alsh.
"This is a great example of partnership working across government departments, Scottish Natural Heritage and academia to deliver a timely and scientifically robust response."
SNH chairman Mike Cantlay said: "Scotland's seas clearly still have many secrets left to tell.
"This is a remarkable discovery and I think we should be proud that our rich waters are so important to flame shells, and as our marine research and survey work continues to reveal, many other wonderful species too."
An MPA is designated on an urgent basis and lasts for a maximum of two years but there are plans is to give Loch Carron the status permanently.
Flame shell beds support a diverse community of other species, meaning protection of this habitat-building species conserves hundreds of other species and promotes local biodiversity.
However, they are sensitive to physical disturbances such as dredging, with substantial and persistent declines observed in the species over the years, raising concerns among marine convervationists.
The reef at Loch Carron was badly damaged by a scallop dredger in April, which led to the loch's designation as an MPA the following month.
When announcing the designation, environment secretary Roseanna Cunningham launched a wider review of vulnerable habitats to identify where else management is needed to prevent further damage or loss.
Cunningham said: "This is a fantastic discovery which shows that the new MPA is making an even more valuable contribution to safeguarding these waters than we first thought.
"I am determined to protect Scotland's rich marine environment as this example shows the importance of considering how our seas are conserved beyond the MPA network.
"We are continuing to work with SNH to review the most vulnerable priority marine features in our coastal waters."