The Hydra Rips a Hole in Itself in Order to Feed
Posted on March 10, 2016
The hydra tears a hold in itself whenever it needs to feed. Biologists and physicists at UC San Diego uncovered the unusual process that enables the tiny, multi-tentacled freshwater creature to feed.
Robert Steele of UC Irvine provided transgenic hydra (pictured above) with green fluorescent and red fluorescent proteins tagged to cytoplasmic proteins to aid the researchers. It was previously thought that the hydra might rearrange the positions of the cells between its tentacles to create an opening but the speed at which the hydra creates a hole and fully opens its mouth helped rule this theory out. Tracking the position of the tagged cells also indicated that the mouth opening did not involve the rearrangement of cells.
Eva-Maria S. Collins, an assistant professor of biology and physics at UC San Diego headed the research teams. Collins says in a statement, "It's fascinating that Hydra has to tear a hole every time it opens its mouth. And that this process happens so quick; this was the first indication to us that mouth opening did not involve cellular rearrangements."
The researchers say there are radially oriented contractile elements called myonemes in the ectodermal cells of the hydra. These act like a muscle so the creature can create a mouth opening. In an experiment the scientists used the muscle relaxant magnesium chloride and the hydra was unable to open a mouth.
A research paper on the study was published here in the Biophysical Journal. Here is a video explaining and showing the hydra mouth. Take a look: