A joint team of biologists and physicists from the University of California, San Diego has made a stunning discovery about the hydra, a small freshwater creature with distant ties to a sea anemone. According to a report from Phys.org, researchers have witnessed the hydra open and close its mouth using a bizarrely complicated process.

Scientists observed the tiny hydra tearing a hole through its epithelial tissue each time it opened its mouth. Researchers were baffled by the process, which remained a complete mystery at the cellular level.

According to assistant biology and physics professor at UCSD and lead author Eva-Maria S. Collins, “The reasons why this work is exciting is that there are very few systems in which you can do quantitative measurements in vivo. Hydra is such a simple organism; it allows us to perform controlled perturbations and quantitative measurements in the natural context.”

When UC Irvine professor Robert Steele developed the transgenic hydra years ago, it allowed scientists to watch individual cells in the tiny creature. Steele, one of the study’s co-authors, injected hydra with green and red fluorescent proteins, which were tagged to cytoplasmic proteins in the ectodermal and endodermal epithelial cells. This enabled scientists to get a clear view of what was going on inside and out of the hydra as it fed.

The hydra uses a set of tentacles to latch onto prey and carry it towards the mouth. Scientists found that as it does this, the skin around its own mouth must be ripped apart each time it goes for a bite.

The breakthrough in understanding occurred when the team observed the morphological changes involved in this process at the cellular levels. They found that the hydra rearranges the cells between its tentacles to make the opening wider. The hydra was able to open and close its mouth by rearranging the positions of its skin cells in under 60 seconds.

The hydra’s unique ability to quickly regenerate lends to quite a bizarre method of eating, but it has provided scientists with a new perspective on the strange creature and what is possible at a cellular level.

A UCSD press release describing the details of the study can be found here.