Sneezing to drain mucus is probably one of the oldest ways organisms remove excess waste. Courtesy of the author
Recently, researchers have found that as one of the oldest surviving multicellular organisms, sponges use “sneezing” to dredge their internal filtration system for obtaining nutrients from water. In addition, other animals living with sponges use this sneezing mucus as food. The research was recently published in Contemporary Biology.
“Our data suggest that sneezing is an adaptation that sponges have evolved to keep themselves clean.” Jasper de Goeij, a marine biologist at the University of Amsterdam in the Netherlands and corresponding author of the paper, said.
While the field has known for years that sponges have had this behavior, the researchers found that these sneezes help sponges remove waste from the body. “Let’s be clear: sponges don’t sneeze like humans, they take half an hour to sneeze. But sponges and human sneezing are both a waste disposal mechanism. de Goeij said.
Sponges collect food by filtering organic matter from the water. They suck in and spew water from different openings, and sometimes sponges suck in too large particles. “Even if the water around them becomes too dirty, sponges can’t move elsewhere.” de Goeij said. That’s when the “sneeze” mechanism comes in handy.
In the video related to the paper, it can be seen that the sponge will slowly release mucus, and the mucus will accumulate on the surface of the sponge. Occasionally, the sponge tissue shrinks, pushing the mucus containing waste into the surrounding water.
While mucus may be waste to sponges, the fish that live around them don’t think so. “We also observed fish and other animals feeding on sponge mucus.” Lead author Dr Niklas Kornder of the team said, “There are some organic matter in the water around the reef, but most of the organic matter is not concentrated enough for other animals to eat. Sponges can convert this substance into mucus that other animals can eat. Kornder said.
The paper documents the “sneezing” behavior of two types of sponges, the Caribbean tubular sponge Aplysina archeri and the Indo-Pacific genus Chelonaplysilla. “We think, if not all, that most sponges sneeze. I’ve seen slime build up on different sponges while diving, and I’ve seen it in photos taken by other scientists for other purposes. Kornder said.
The authors say the findings provide an opportunity to better understand the material cycles of some of the oldest postbiotic animals. Regarding sponge “sneezing”, there are still many aspects that remain unresolved. “In the video, you can see the slime moving along a specific path on the surface of the sponge before it gathers. I have some assumptions about this, but more analysis is needed to find out what happened. Kornder said.
“There are a lot of scientists who think sponges are very simple creatures, but their flexibility to adapt to their environment is surprising,” de Goeij said. (Source: China Science Daily Jinnan)
Related paper information:https://doi.org/10.1016/j.cub.2022.07.017