Hydra became a subject of a recent study because of its unique ability to tear itself in order to gulp its prey. Hydra is a small freshwater creature which lies beneath water. It has no mouth or lips unlike majority of creatures. As part of the study, biophysicists have made a video of hydra which led to the discovery about potential of hydra to pull apart itself temporarily and later to restore damage to tissues.

The study led by Eva-Maria Collins, a physicist and cell biologist at the University of California San Diego was published in the Biophysical Journal. The boneless hydra is usually smaller than half an inch. Its one end remains attached to plant stem, while other is suspended and flexible though which a prey is attacked. Hydra preys on microorganism such as microscopic crustaceans and copepods.

To understand mechanism through which hydra attain reversible flexibility, the team working with Collins analyzed genetics of a species called Hydra vulgaris. They put its skin under a microscope to understand its features. They found that the species had two skins, inner and outer. For the experiment, the research team genetically modified hydra to add colors to both the skins. The inner magenta colored is endoderm whereas the green outer layer is called ectoderm.

The hydra is astonishingly flexible; the cells in hydra pull each other to make a mouth as wide as possible. These muscle cells are found in the outer layer of the creature. The fibers are arranged in circles and when these fiber contract they tug on skin cells enabling stretching. In most of the animals, when such an opening is achieved the cells move out of place; however, this is not the case with hydra.

“We still have a lot of work to do to really understand how signals from the nervous system trigger mouth opening. And then we also would like to understand how the mouth closes and what the consequences are for the individual cells to accommodate this amazing stretching, which can be more than 100 percent strain”, said Collin on need of future research.