Tiny crustaceans previously recorded at two locations in the British Isles have been found in a loch near Kinross.
Cytherissa lacustris, a species of creature called ostracods, only grow to about a millimetre in length.
Until now, this species had only been known to be living at Loch Assynt in Scotland and a site in north England.
David Horne, professor of micropalaeontology at Queen Mary University of London, found Cytherissa lacustris in Loch Leven.
The species is rare in Britain, but “quite well-known” elsewhere in the northern hemisphere, including parts of Europe and Canada, said Prof Horne.
He was alerted to the possibility that the creatures were living in Loch Leven during a visit to the Discovery Museum in Newcastle upon Tyne.
Prof Horne had gone there to study a large archive of ostracods collected by a 19th Century naturalist, George Brady.
The scientist said: “I came across a microscope slide containing ostracods collected from Loch Leven in June 1890, among which were several specimens of Cytherissa lacustris.
“In some I could see appendages protruding from between their shells, a clear indication that they had been alive at the time of collection.”
Prof Horne took samples from Loch Leven in August and has been analysing them since then.
This year, Jim Davy at University College London imaged some of the ostracod specimens, including Cytherissa lacustris on a scanning electron microscope.”
Prof Horne studies the fossil remains of ostracods to better understand winter and summer temperatures experienced by early humans in the British Isles.
Finding locations of living ostracods is key to this work.
He is planning further research of the Cytherissa lacustris living in Loch Leven.