A video of small hair-like structures fluttering in the airways of a child with a genetic disease has won an international microscopic imagery contest.
The video, taken by Ning Xu, a researcher at Tsinghua University in China, is one of dozens highlighted by the 2026 Nikon Small World In Motion competition.
The competition is open to anyone around the world with an interest in film or time-lapse photography through a microscope.
Dr Xu's video, magnified to 100 times in size, shows cilia that line airways to out mucus.
In people like this child with primary ciliary dyskinesia (PCD), they move and make it harder to keep lungs clear.
Dr Xu used a series of complicated light waves to illuminate different parts of the sample in colour, allowing researchers to gain a better understanding of PCD.
Vietnamese researcher Nguyen Nam Nhat was awarded second place for a video of a microscopic roundworm, or nematode, encountering a single-celled organism called a Dileptus.
Mr Nguyen said the footage was a chance observation.
"I had intended only to film Dileptus specimens from a naturally collected water sample in order to study their morphology," he said.
But a rogue roundworm appeared, pressing itself up against the Dileptus. The Dileptus lost a chunk of its small body in the struggle to escape.
"After examining several similar cases, I found that pressing against or immobilising other organisms appears to be one of the typical defensive behaviours employed by nematodes," Mr Nguyen said.
Microscopic photographer Benedikt Pleyer won third place for a video of various types of jellyfish larvae.
Mr Pleyer set up the shots by suspending water droplets on a string over a petri dish, sliding small larvae into the drops.
Most jellyfish-containing droplets splashed into the petri dish too quickly to film, so it took months to collect the footage.
Other entrants received honourable mentions such as a video of the Cyerce kikutarobabai sea slug, which is native to the western Pacific Ocean.
Animals weren't the only things on display, with one video showing the growth of the Penicillium venetum fungus, which can cause rot in garlic.
Another video showed the formation of crystals of the food additive monosodium glutamate (MSG).
Mr Pleyer also received an honourable mention for a video of tropical phytoplankton he had collected and cultured.
The phytoplankton, which are magnified to 200 times their size, glow when they are physically disturbed.
"The biggest problem with this bioluminescent reaction is how to trigger it and to at the same time get a clear shot," Mr Pleyer said.
Jostling the phytoplankton to get a reaction makes the camera shake too much at this resolution, so Mr Pleyer used glycerol to fix them in place, and a small electric charge to trigger the bioluminescence.
Tardigrades, animals half a millimetre in size, featured in several other videos.
Mr Pleyer said amateur microscopy enthusiasts had a role to play in science.
"The microcosmos is a vast field and we don't know much about it yet," he said.
In the past decade, it's become much easier and cheaper to see moving things at the micro scale.
"With the digital revolution, a sensor, a camera, you can just go," Mr Pleyer said.
The full list of winners and honourable mentions are published on the competition's website.