WATCH: Sea Sponges ‘Sneezing’ Out Their Mucus Is Equal Parts Bizarre and Mesmerizing

by Sean Griffin

Like many sea creatures, sea sponges prove enigmatic to scientists. In a new study, researchers discovered that sea sponges secrete and filter out waste by letting out what looks like a “sneeze.”

Researchers captured the behavior in a time-lapse video. According to Business Insider, the discovery could help scientists better understand how sponges evolved.

“Our data suggest that sneezing is an adaptation that sponges evolved to keep themselves clean,” Jasper de Goeij, a marine biologist at the University of Amsterdam and author of the new paper, stated in a press release.

Sea sponges are very old: scientists estimate they are over half a billion years old. The species consists of simple multicellular organisms with no brains.

The video below—which can also be seen here—taken by the research group and credited to Current Biology/Kornder et al., show the sponge’s “sneeze.” And the video is both equally horrifying as it is enticing. We can’t explain it.

In a recent study published in Current Biology on Wednesday, researchers recorded two species of sponges letting out these “sneezes” that contract their entire bodies. The two species include the Caribbean Aplysina archeri, also known as the stove-pipe sponge, and a species of the Chelonaplysilla genus, found in the Indo-Pacific region.

“Let’s be clear: Sponges don’t sneeze like humans do,” de Goeij said in the press release. De Goeij added that a sponge sneeze takes about a half an hour to complete. “But both sponge and human sneezes exist as a waste disposal mechanism,” he said.

Sea Sponges Contract Their Bodies While Sneezing

Sea sponges are classified as filter feeders. Filter feeders grab particles from the water for nourishment, particles like bacteria and plankton.

A sponge’s pores get clogged with the other gunk not eaten. However, they clean their pores by using this recently discovered sneezing mechanism. This allows them to get rid of non-digestable material.

Water passes through their tiny pores. Their pores, shaped like chimneys, are called ostium.

The sponges slowly release the mucus which contains waste, and these bubble to the sponge’s surface. Moreover, they occasionally contract their bodies in a slow sneeze to get rid of the unwanted material.

However, unsurprisingly, researchers found fish and other animals feeding off of the sponge’s recently released mucus.

“Some organic matter exists in the water surrounding the coral reef, but most of it is not concentrated enough for other animals to eat. Sponges transform this material into eatable mucus,” Kornder, a study co-author, stated in the press release.

Researchers say that they’re still evaluating the information they’ve received.

“In the videos, you can see that the mucus moves along defined paths on the surface of the sponge before accumulating,” Kornder, said, adding, “I have some hypotheses, but more analysis is needed to find out what is happening.”