Hydra vulgaris has caught attention of many researchers for its remarkable ability to tear itself in order to gulp its food every time it is hungry. It will be interesting to note that Hydra recovers the rip soon through tissue regeneration. Hydra does this unique action as its skin cells separate to give way for an opening through which food is ingested and soon the opening gets closed.

The process of opening and closing of mouth is so rapid that researchers in past couldn’t find how tissues attain this level of flexibility. However, researchers at the University of California, San Diego found mechanism behind this ability of Hydra vulgaris to do so. The study was published in the Biophysical Journal.

The biologists captured Hydra vulgaris eating its prey, which are usually microorganisms such as microscopic crustaceans and copepods. Hydra pulls its muscle cells found in outer layer as wide as possible. Fibers are generally arranged in circles in hydra and on contracting they tug on to skin cells to enable starching.

“The fact that the cells are able to stretch to accommodate the mouth opening, which is sometimes wider than the body, was really astounding. When you watch the shapes of the cells, it looks like even the cell nuclei are deformed,” said study lead Eva-Marie Collins, a physicist and cell biologist at university of California, San Diego.

The team of researchers working with Collins has led to the discovery how hydra attains this flexibility by studying its skin under microscope. They found that species has two skin layer one is inner while other is outer. The inner layer is called endoderm, while the outer is ectoderm.