'UK's biggest' mud volcano worm habitat in Argyll loch
What has been described as the "UK's biggest and best known example" of an unusual marine habitat has been found in a Scottish loch.
Mounds of mud of up to a metre (3ft) high were recorded in Argyll's Loch Sween in surveys by scientists.
Made by creatures called mud volcano worms, the mounds cover an area of about 1,630 acres (660ha).
"Rich beds" of sea pens were also found covering seabed in areas near Loch Linnhe in the Highlands.
South of Arran, ocean quahog clams were widely recorded and found in "abundant" numbers at one site.
Quahog clams are the world's longest living molluscs. One dredged up off Iceland in 2007 was aged between 405 and 410 years old.
Researchers from Bangor University in north Wales calculated its age by counting rings on its shell.
The clam was nicknamed Ming, after the Chinese dynasty in power when it was born.
Scottish lochs and seabed were surveyed to better understand the state of marine wildlife and habitats.
The studies formed part of work led by Marine Scotland to develop a network of Marine Protected Areas (MPAs).
The results will also help inform future decisions about marine renewable energy development.
A range of techniques were used to explore areas in the Firth of Clyde, Loch Sween and around Loch Linnhe and also Orkney.
These included remote video footage, sampling the seabed and diving.
Scientists from Scottish Natural Heritage (SNH), Scottish Association for Marine Science (Sams) and Edinburgh's Heriot-Watt University carried out the surveys.
Maerl and horse mussel beds and northern sea fan and deep sponge communities were also found.
Other surveys have recorded sea potato, a relative of the common sea urchin, in Loch Linnhe and dahlia anemone in Loch Duich in the north west Highlands.
Thirty-three sites around the coast of Scotland are being considered as possible MPAs.