Surprising behavior: Sponges "sneeze" to dispose of waste, spraying mucus into the sea
Sponges are one of the oldest creatures on Earth and play an important role in many underwater ecosystems. New research has found that sponges "sneeze" to clean their waterways. With each sneeze, the sponge releases a mucus that is eaten by other animals.
The study, conducted by Niklas Kornd of the University of Amsterdam (UvA) and colleagues, published in the scientific journal Current Biology on August 10, 2022.
Fossil evidence shows that sponges date back 650 million years and are one of the oldest animals on Earth. They may appear simple creatures at first, but sponges play a key role in many underwater ecosystems. They are fed by pumping water through a network of access channels in the body, filtering up to thousands of litres of seawater every day. By perfecting this process, sponges are able to feed on dissolved organic matter, a food source that most other marine life cannot obtain.
Different types of sponges in the ocean A. Chondrilla caribensis，b Aplysina archeri，c Verongula gigantea，d Xestospongia muta
Surprising behavior
After feeding on dissolved organic matter, the sponge produces a slimy-like waste carrier. "Waste is expected to be released through their outflow holes along with the outflow water," Kornd explains. To study this theory, the scientists took purple tubular sponge specimens and placed them in an aquarium to collect mucus. They also placed a camera to capture the time delay on the surface of the sponge.
The researchers were very surprised, with Cohend sharing: "Every three to eight hours, the sponge contracts and then relaxes its surface tissue. At first, we thought our attention was temporarily off, but soon realized that the animals were "sneezing." ”
The video shows that every time you sneeze, the collected mucus is released and the sponge surface remains clean. Although sponge sneezing has been described before, it is often thought of as a way for sponges to regulate water flow. The passage of time also indicates that the mucus is constantly flowing out of the inflow opening, rather than outflowing the opening, and is slowly transported along different paths to the central collection point on the surface of the sponge.
While diving in the Caribbean, scientists have seen many small animals feed on the energetic mucus on sponges. This directly shows how sponges harness the energy of dissolved organic matter in water and convert it into food sources into food chains that benefit the entire ecosystem.