The multi-headed Hydra monster of Greek mythology is more terrifying as compared to its real-life namesake: a species of tiny freshwater polyps that feeds on shrimp and other tiny invertebrates.

However, the less than one-inch creatures possess a fearsome capability that could knock out even the original Hydra. The tiny freshwater-dwelling hydra, whenever eats, has to rip apart their mouth. It might sound strange but research teams have been wondering over this phenomenon for quite long.

Their tubular bodies’ opening isn’t only closed, instead their mouths actually disappear until the time comes to digest dinner, which they obtain using poison-barbed tentacles. When they are done with it, their opening gets sealed up again with a tissue layer.

For the first time ever, scientists at the University of California San Diego and Irvine campuses used color-coded, transgenic proteins for tracking cells around the areas of hydras’ mouth.

The research suggested that the openings are created temporarily by altering the size of the cells, and not by rearranging them, as was thought earlier.

In a press release, lead author Eva-Maria Collins, a biophysicist at UC San Diego, said that they can attempt to understand what looks like the quite complicated processes in the living animal using relatively easy physics. However, the trick was looking for a way of watching the cells in vivo, in which nobody has succeeded so far.

Some years back, co-author Robert Steele, from UC Irvine, came up with transgenic hydra, a hydra composed of some cells transferred from another species. In this case, he transferred green and red proteins into other proteins in the epithelial cells in the inner and outer tissue layers of the hydra, both of which experience changes every time when mouth is created.

Researchers had previously thought that cells surrounding the mouths’ center don’t change their position, but the UC team found that they drastically change shape.