This gorgeous image of a stained adult marine worm was created by former EMBL postdoc Hernando Martinez using structured microscopy. The worm itself was captured during plankton extraction off the coast of Sweden. There are over 10 000 species of these swimming worms, and they have adapted to every imaginable marine habitat.
Each body segment has a pair of fleshy protrusions that bear many bristles made of chitin. Therefore, they are sometimes called bristle worms. Polychaetes, as a class, are extremely robust and widespread: species can be found in the coldest oceans but also near hydrothermal vents, and from the ocean’s surface to its greatest depths.