Snot and Jewels

Diatoms are tiny single-celled creatures found in water all over the world in a startling array of shapes and colours – earning them the nickname the jewels of the sea. Some species of these microalgae bob around in currents while others propel themselves – here computer software tracks the graceful movement of Craspedostauros australis from above. But underneath is a different story. Researchers discover C. australis steer themselves around using gusts of sticky mucilage pushed through slits in their undercarriage. Different patterns of gluey spurts, forced through differently shaped gaps, help them change direction as they glide. While not directly harmful to humans, algal mucilage, often referred to as “sea snot”, can harbour dangerous bacteria such as E.Coli. Yet, diatoms also produce up to half the world’s oxygen as a byproduct of their photosynthesis, highlighting our contrasting relationships with these ancient microscopic creatures.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Video from work by Stefan Golfier and colleagues
• B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany
• Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Proceedings of the National Academy of Science (PNAS), April 2026