North Wales has become the latest area where small jellyfish-like creatures have washed up in hordes.
Tony Jones spotted the creatures at Porth Ysgo beach near Aberdaron
Velella velella, or By-the-wind Sailors, have turned up on the Lleyn peninsula, at Porth Ysgo near Aberdaron, and others near Porthmadog.
They are also in their millions on many beaches all along the coast of Wales, amid speculation that global warming is sending them further north.
They are blue, measure up to 10cm (4in) and are harmless to people.
"At the time we had no idea what the odd little creatures were," said Gwenllian Jones, from Rhiw.
"My husband Tony took a picture and we did some research on it after we got home."
Cliff Benson of the Sea Trust, which monitors marine life off the west Wales coast, said that while rare, they were becoming more common.
"They are amazing things that have a sort of sail on their back and live on the surface of the sea," he said.
"They can be found in their millions and millions if not billions in the Atlantic.
"Two or three years ago there were a lot washed ashore - it does not happen every year and they are a bit of a phenomenon."